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3 pages, 687 KiB

Open AccessAbstract

Contact Angle Measurement through Liquid Flow in Curved Open Microchannels

by Tina Mitteramskogler, Andreas Fuchsluger, Rafael Ecker, Thomas Wilfinger, Bernhard Jakoby and Robert Wille

Proceedings 2024, 97(1), 1; https://doi.org/10.3390/proceedings2024097001 - 12 Mar 2024

Viewed by 327

Abstract

Whether liquids in open microchannels show spontaneous capillary flow or not crucially depends on the involved surface energies and the shape of the microchannel. In this study, we present a two-dimensional model based on the Gibb’s free energy of a system that predicts [...] Read more.

Whether liquids in open microchannels show spontaneous capillary flow or not crucially depends on the involved surface energies and the shape of the microchannel. In this study, we present a two-dimensional model based on the Gibb’s free energy of a system that predicts the presence of spontaneous capillary flow in open microchannels. We expand our model to include curved microchannels and verify our findings using simulations of a liquid surface with Surface Evolver. Finally, we comment on how these results can be used to measure the liquid contact angle through open capillary flow. Full article

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3 pages, 147 KiB

Open AccessAbstract

Concept Drift Mitigation in Low-Cost Air Quality Monitoring Networks

by Gerardo D’Elia, Matteo Ferro, Paolo Sommella, Sergio Ferlito, Saverio De Vito and Girolamo Di Francia

Proceedings 2024, 97(1), 2; https://doi.org/10.3390/proceedings2024097002 - 12 Mar 2024

Viewed by 326

Abstract

Future air quality monitoring networks will include fleets of low-cost gas and particulate matter sensors calibrated using machine learning techniques. Unfortunately, it is well known that concept drift is one of the primary causes of losses in data quality in operational scenarios. This [...] Read more.

Future air quality monitoring networks will include fleets of low-cost gas and particulate matter sensors calibrated using machine learning techniques. Unfortunately, it is well known that concept drift is one of the primary causes of losses in data quality in operational scenarios. This work focuses on addressing a low-cost NO₂ sensor calibration model update triggered via a concept drift detector. This study defines which data are most appropriate for use in the model updating process in order to maintain compliance with the relative expanded uncertainty (REU) limits established by the European Directive, as well as evaluate the potential of general and importance-weighted calibration models in the mitigation of concept drift effects. Full article

3 pages, 414 KiB

Open AccessAbstract

The Application of Back-Compatible Color QR Codes to Colorimetric Sensors

by Ismael Benito-Altamirano, Ferran Crugeira, Míriam Marchena and J. Daniel Prades

Proceedings 2024, 97(1), 3; https://doi.org/10.3390/proceedings2024097003 - 13 Mar 2024

Viewed by 348

Abstract

We present the application of QR Codes as carriers for colorimetric dyes, whereby this refined version of machine-readable patterns applied to colorimetric sensing also allows us to maintain the data from the QR Code standard in a back-compatible way, which means that the [...] Read more.

We present the application of QR Codes as carriers for colorimetric dyes, whereby this refined version of machine-readable patterns applied to colorimetric sensing also allows us to maintain the data from the QR Code standard in a back-compatible way, which means that the QR Code is still able to encode digital data (readable with a standard QR Code decoder) alongside a hundred colorimetric references and the dyes. Also, we discuss in detail the effectiveness of different color correction methods in attaining color accuracy levels suited for sensing via colorimetry. Moreover, we illustrate how color correction techniques can be applied to take advantage of having hundreds of color references, with an exemplary case of a CO₂ printed sensor used to monitor the integrity of modified atmosphere packaging (MAP). Full article

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3 pages, 421 KiB

Open AccessAbstract

Data Processing Procedure for Real-Time Odour Concentration Estimation at Industrial Plant Fenceline by Sensor-Based Tools

by Christian Ratti, Beatrice Julia Lotesoriere, Carmen Bax and Laura Capelli

Proceedings 2024, 97(1), 4; https://doi.org/10.3390/proceedings2024097004 - 13 Mar 2024

Viewed by 304

Abstract

The realisation of an electronic nose network for the monitoring of the odour concentrations at the fenceline of a waste treatment plant has been investigated. One of the main challenges for instrumental environmental monitoring concerns the interference of the daily variability of humidity [...] Read more.

The realisation of an electronic nose network for the monitoring of the odour concentrations at the fenceline of a waste treatment plant has been investigated. One of the main challenges for instrumental environmental monitoring concerns the interference of the daily variability of humidity and temperature of the ambient air to which sensors are exposed. In this study, we propose a solution to overcome this problem, implementing a specific normalisation pretreatment into the data processing procedure. The preliminary results obtained show a better classification and quantification performance whenever humidity model compensation is applied. Full article

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3 pages, 401 KiB

Open AccessAbstract

Amperometric Biosensing of L-Glutamate Using Reduced Graphene Oxide and Glutamate Oxidase

by Ieva Sakinyte-Urbikiene, Vidute Gureviciene and Julija Razumiene

Proceedings 2024, 97(1), 5; https://doi.org/10.3390/proceedings2024097005 - 13 Mar 2024

Viewed by 374

Abstract

The determination of L-glutamate in biological media is very important, as it is the most common excitatory neurotransmitter related to some neurological diseases, such as Parkinson’s, communication dysfunction, stroke, epilepsy and schizophrenia. When aiming to study the pathways of these diseases, as well [...] Read more.

The determination of L-glutamate in biological media is very important, as it is the most common excitatory neurotransmitter related to some neurological diseases, such as Parkinson’s, communication dysfunction, stroke, epilepsy and schizophrenia. When aiming to study the pathways of these diseases, as well as for the evaluation of medical treatments, it is very important to have rapid and reliable methods for the determination of L-glutamate. This study presents the new approach of an enzyme-based biosensor operating at −0.1 V, which ensures its good sensitivity and selectivity. The reduced graphene oxide used in the biosensor allowed for the monitoring of L-glutamate via the electro-oxidation of the NH₃ released during the reaction catalyzed by Glutamate oxidase. Full article

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3 pages, 153 KiB

Open AccessAbstract

Adoption of a Social Robot in a Sub Intensive Care Unit for the Autonomous Computation of Criticality Scores

by Giovanni Piccininno, Nicola Laurieri, Alessandro Anselmo, Sergio Russo, Alessandra Sorrentino, Daniele Sancarlo, Grazia D’Onofrio, Letizia Lorusso, Laura Fiorini, Filippo Cavallo, Antonio Greco and Francesco Giuliani

Proceedings 2024, 97(1), 6; https://doi.org/10.3390/proceedings2024097006 - 13 Mar 2024

Viewed by 342

Abstract

We describe an innovative case study focusing on a social robot able to help healthcare professionals compute criticality scores for patients hosted in a Geriatric Sub-Intensive Care Unit. The aim is to establish the feasibility of a scenario in which the robot modulates [...] Read more.

We describe an innovative case study focusing on a social robot able to help healthcare professionals compute criticality scores for patients hosted in a Geriatric Sub-Intensive Care Unit. The aim is to establish the feasibility of a scenario in which the robot modulates the frequency of its visits to the room of bedridden patients, based on the criticality scores it has computed. Full article

3 pages, 728 KiB

Open AccessAbstract

Development of Triboelectric Devices for Human–Machine Interface Applications

by Andreas Anastasopoulos, Vasiliki Zacharia, Achilleas Bardakas and Christos Tsamis

Proceedings 2024, 97(1), 7; https://doi.org/10.3390/proceedings2024097007 - 13 Mar 2024

Viewed by 565

Abstract

Haptic feedback, also known as tactile sensing, plays a vital role in human interactions with the external environment. The artificial replication of tactile sensations using triboelectric sensors has sparked the attention of the scientific community by developing advanced electronic skins with haptic perception. [...] Read more.

Haptic feedback, also known as tactile sensing, plays a vital role in human interactions with the external environment. The artificial replication of tactile sensations using triboelectric sensors has sparked the attention of the scientific community by developing advanced electronic skins with haptic perception. In this work, we design and fabricate different flexible tactile sensors based on the triboelectric effect. The triboelectric sensors were evaluated in respect of their ability to identify different materials that were in contact with the sensor. Our results show that the triboelectric signal depends on the nature of the substrate, and a clear distinction among different substrates could be obtained. Full article

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3 pages, 493 KiB

Open AccessAbstract

Advanced Analysis of Solutions with a Low-Cost Electronic Device Containing Color Sensor and Programmable Red, Green, and Blue (RGB) LED

by Ondřej Keresteš and Miroslav Pohanka

Proceedings 2024, 97(1), 8; https://doi.org/10.3390/proceedings2024097008 - 13 Mar 2024

Viewed by 313

Abstract

Although methods for point-of-care testing gains are growing in importance, it is still essential to develop alternatives for tests performed centrally on commercial analyzers, thus making photometry cheaper and more accessible to the public. We introduce a low-cost photometer based on the Arduino [...] Read more.

Although methods for point-of-care testing gains are growing in importance, it is still essential to develop alternatives for tests performed centrally on commercial analyzers, thus making photometry cheaper and more accessible to the public. We introduce a low-cost photometer based on the Arduino with APDS9960 sensor and RBG LED in this work. A photometric platform based on a color sensor can gain a four-signal response. Acetylcholinesterase was chosen as the model element for the biosensor. The device can also easily be upgraded for fluorometric assays. Full article

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3 pages, 178 KiB

Open AccessAbstract

Development of a Wearable Sweat Sensor Chip Based on Surface-Enhanced Raman Spectroscopy

by Cristiano D’Andrea, Martina Banchelli, Chiara Amicucci, Panagis Polykretis, Filippo Micheletti, Marella de Angelis, Yurim Han, Heebo Ha, Byungil Hwang and Paolo Matteini

Proceedings 2024, 97(1), 9; https://doi.org/10.3390/proceedings2024097009 - 13 Mar 2024

Viewed by 353

Abstract

A wearable sweat sensor chip based on surface-enhanced Raman spectroscopy is developed. The plasmonic core of the chip, obtained by depositing silver nanowires on a PTFE porous membrane, permits the direct and label-free detection of urea and lactate at physiological concentration in combination [...] Read more.

A wearable sweat sensor chip based on surface-enhanced Raman spectroscopy is developed. The plasmonic core of the chip, obtained by depositing silver nanowires on a PTFE porous membrane, permits the direct and label-free detection of urea and lactate at physiological concentration in combination with the evaluation of sweat pH in the range between 4 and 9. Full article

3 pages, 968 KiB

Open AccessAbstract

Driver Position Measured Based on Textile Capacitive Sensor Array

by Marc Martínez-Estrada, Ignacio Gil and Raúl Fernández-García

Proceedings 2024, 97(1), 10; https://doi.org/10.3390/proceedings2024097010 - 13 Mar 2024

Viewed by 278

Abstract

A woven textile capacitive sensor array fully integrated on a car seat is presented to detect the driver’s position. The sensor array consists of two planar interdigital capacitive sensors located on the base and the backrest of the seat. With this sensor array, [...] Read more.

A woven textile capacitive sensor array fully integrated on a car seat is presented to detect the driver’s position. The sensor array consists of two planar interdigital capacitive sensors located on the base and the backrest of the seat. With this sensor array, the position of the driver can be continually measured in real time with potential detection for events such as back detaching or buttocks displacement, which could indicate a risk of traffic accidents. Full article

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3 pages, 458 KiB

Open AccessAbstract

An Autonomous Multi-Technological LoRa Sensor Network for Landslide Monitoring

by Mattia Ragnoli, Paolo Esposito, Gianluca Barile, Giuseppe Ferri and Vincenzo Stornelli

Proceedings 2024, 97(1), 11; https://doi.org/10.3390/proceedings2024097011 - 13 Mar 2024

Viewed by 384

Abstract

Hazards like landslides have significant economic and societal repercussions; hence, the issue of remote structure health monitoring has grown in significance for geologic applications. Wireless sensor networks (WSNs) stand out among the new sensing architectures as a particularly well-suited solution, thanks to the [...] Read more.

Hazards like landslides have significant economic and societal repercussions; hence, the issue of remote structure health monitoring has grown in significance for geologic applications. Wireless sensor networks (WSNs) stand out among the new sensing architectures as a particularly well-suited solution, thanks to the versatility they offer. This research, necessary for safety reasons, predictive maintenance and emergency evacuation, presents a WSN-based landslide monitoring system with multi-technology sensor implementation. Its goal is to track the land movements on a hillside. The network is composed of long range (LoRa) sensor nodes connected using a LoRaWAN media access control (MAC) layer. The nodes are several and of different natures and help monitor land movements, hydric parameters and rockfall events, and they also offer a camera view of the landslide in case of an emergency. The system is built on an Internet of Things (IoT) framework, enabling online access to data and reports. The final work will include a system description of the hardware and functionality of all the devices, a description of the web section for remote monitoring, a power analysis and statistics from actual scenarios. Full article

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3 pages, 734 KiB

Open AccessAbstract

A Process to Realize 2PP-Based Electrodes in Microfluidic Channels

by Wiebke Gehlken, Melanie Kirsch and Michael J. Vellekoop

Proceedings 2024, 97(1), 12; https://doi.org/10.3390/proceedings2024097012 - 13 Mar 2024

Viewed by 315

Abstract

In this work, a process to realize metallized 2-photon-polymerized (2PP) structures in prefabricated microfluidic channels is presented, aiming at 3D-structured electrodes. The channel is fabricated using a single-layer process of SU-8 to realize vertical sidewalls with a height and width of 300 µm. [...] Read more.

In this work, a process to realize metallized 2-photon-polymerized (2PP) structures in prefabricated microfluidic channels is presented, aiming at 3D-structured electrodes. The channel is fabricated using a single-layer process of SU-8 to realize vertical sidewalls with a height and width of 300 µm. Electrodes in a ring shape with an outer diameter of 250 µm are printed in the channel using 2PP and metallized via sputtering. Using chromium as sacrificial layer, a lift-off is performed to structure the metal. This allows us to fabricate individual electrically controllable 3D electrodes that use the total height and width of the channel. Metallization with good step coverage on ring-shaped 3D structures in the high microchannel was achieved, which was confirmed using conductivity tests. Full article

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3 pages, 1283 KiB

Open AccessAbstract

Active Conversion of Bubbly Flow into Slug and Annular Flow during Microchannel Flow Boiling Using Thin-Film Platinum Microheaters

by Mark Schepperle, Sebastian Arnold and Peter Woias

Proceedings 2024, 97(1), 13; https://doi.org/10.3390/proceedings2024097013 - 14 Mar 2024

Viewed by 315

Abstract

This paper reports, for the first time, on the use of thin-film platinum microheaters to influence the flow boiling of DI water in microchannels with rapid low power heating pulses. A custom-designed control module allows microheaters to be actuated simultaneously and independently, enabling [...] Read more.

This paper reports, for the first time, on the use of thin-film platinum microheaters to influence the flow boiling of DI water in microchannels with rapid low power heating pulses. A custom-designed control module allows microheaters to be actuated simultaneously and independently, enabling precise local control of flow regimes along an entire channel. In this study, bubbly flow was converted into a slug and annular flow. This pioneering technique promises a radical improvement in the heat transfer and performance of flow-boiling cooling devices by actively targeting flow conditions with high heat dissipation. Full article

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3 pages, 372 KiB

Open AccessAbstract

A Transformer-Based Front-End Circuit for Grounded Capacitive Sensors with Square-Wave Excitation

by Marcelo A. Haberman, Enrique M. Spinelli and Ferran Reverter

Proceedings 2024, 97(1), 14; https://doi.org/10.3390/proceedings2024097014 - 14 Mar 2024

Viewed by 345

Abstract

This work proposes and experimentally characterizes a novel front-end circuit for capacitive sensors with one electrode grounded, which are quite common in liquid-level and position measurement applications. The circuit relies on a properly shielded custom transformer, as already suggested in the literature, but [...] Read more.

This work proposes and experimentally characterizes a novel front-end circuit for capacitive sensors with one electrode grounded, which are quite common in liquid-level and position measurement applications. The circuit relies on a properly shielded custom transformer, as already suggested in the literature, but uses a square excitation instead of a sinusoidal excitation, thus being a simpler solution. Furthermore, the sensor signal is read by a charge amplifier with a single supply voltage, instead of a transimpedance amplifier with a split supply voltage. The preliminary experimental results show an input–output characteristic with a non-linearity error lower than 0.5% FSS in the [0, 33] pF measuring range. Full article

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3 pages, 424 KiB

Open AccessAbstract

A Novel Indium Oxide-Based Nanostructured Material Designed for CO₂ Detection

by Arianna Rossi, Barbara Fabbri, Elena Spagnoli, Andrea Gaiardo, Matteo Valt and Vincenzo Guidi

Proceedings 2024, 97(1), 15; https://doi.org/10.3390/proceedings2024097015 - 14 Mar 2024

Viewed by 338

Abstract

Low-cost sensors working at low/room temperature for CO₂ mapping in indoor–outdoor environments are in growing demand. Solid-state gas sensors are a suitable alternative to expensive optical sensors, but to date, materials designed for chemoresistive devices have not proven functional for CO₂ [...] Read more.

Low-cost sensors working at low/room temperature for CO₂ mapping in indoor–outdoor environments are in growing demand. Solid-state gas sensors are a suitable alternative to expensive optical sensors, but to date, materials designed for chemoresistive devices have not proven functional for CO₂ detection. This work addresses this challenge both in terms of sensing materials research, with the innovative use of alkali metals as dopants in semiconductors, and in terms of deeply understanding the sensing mechanism through DRIFT spectroscopy. The result is a sensor operating at 200 °C that detects CO₂ between 250–5000 ppm with a negligible effect of humidity above 17 RH%. Full article

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3 pages, 336 KiB

Open AccessAbstract

Available Kinetic Energy Sources on the Human Body during Sports Activities: An Optimization Investigation Using Cantilevered Piezoelectric Harvester Model

by Damien Hoareau, Gurvan Jodin, Abdo-Rahmane Anas Laaraibi, Jacques Prioux and Florence Razan

Proceedings 2024, 97(1), 16; https://doi.org/10.3390/proceedings2024097016 - 14 Mar 2024

Viewed by 300

Abstract

Previous work has shown that the impacts induced by human sport activities are one of the most relevant features to operating a cantilevered piezoelectric harvester. In addition, the optimal orientations of the simulated harvester according to body parts were investigated. In this contribution, [...] Read more.

Previous work has shown that the impacts induced by human sport activities are one of the most relevant features to operating a cantilevered piezoelectric harvester. In addition, the optimal orientations of the simulated harvester according to body parts were investigated. In this contribution, we study the influence of the harvester dimensions on the simulated harvested energy. The results show that for a defined mass of active material and the optimal harvester orientation, a low-frequency harvester is preferred. Thus, the harvester operating frequencies, orientation, and location on the human body are explored. Full article

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3 pages, 474 KiB

Open AccessAbstract

Atmospheric Particulate Matter Sensing with Commercial Quartz Crystal Microbalance: A Feature Extraction and Evaluation Study

by Ettore Massera, Brigida Alfano, Tiziana Polichetti and Maria Lucia Miglietta

Proceedings 2024, 97(1), 18; https://doi.org/10.3390/proceedings2024097018 - 14 Mar 2024

Viewed by 318

Abstract

This article presents the results of a study of the ability of the vibrating membranes, such as quartz crystal microbalances, to measure particulate matter. This study builds on the feasibility study previously presented using a low-cost commercial product suitable for research and development [...] Read more.

This article presents the results of a study of the ability of the vibrating membranes, such as quartz crystal microbalances, to measure particulate matter. This study builds on the feasibility study previously presented using a low-cost commercial product suitable for research and development purposes. This work shows the results of the treatment of the vibrating surfaces of the membranes, which significantly amplifies their sensitivity. The study provides an analysis of the impedance spectra of the membranes during their exposure to known concentrations of particulate matter. The results of the study show electronic features highly correlated with the concentration of particulate matter in the air. Full article

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3 pages, 432 KiB

Open AccessAbstract

Cheap, Tunable and Versatile Nanoparticles for Explosive Detection: Quantum Dots

by Federica Mitri, Andrea De Iacovo, Serena De Santis and Lorenzo Colace

Proceedings 2024, 97(1), 19; https://doi.org/10.3390/proceedings2024097019 - 14 Mar 2024

Viewed by 337

Abstract

In recent years, fluorescent probes based on quantum dots have become a popular tool for explosive detection. However, despite their high sensitivity, these probes still require lab-based instrumentation and procedures that are difficult to be converted into a small, low-power system. Furthermore, they [...] Read more.

In recent years, fluorescent probes based on quantum dots have become a popular tool for explosive detection. However, despite their high sensitivity, these probes still require lab-based instrumentation and procedures that are difficult to be converted into a small, low-power system. Furthermore, they are hardly applied to the detection of vapor-phase explosives, being limited to water samples. Herein, we propose two alternative ways of employing quantum dots as a sensing material to build simple devices for vapor explosive detection. First, we report on a compact optical system where a solid-state QD photoluminescent probe is successfully integrated with a QD photodetector on the same silicon chip. Therefore, a high-performance chemiresistive sensor whose electrical resistance changes proportionally to the target gas concentration is proposed. Full article

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3 pages, 1064 KiB

Open AccessAbstract

Classification in Early Fire Detection Using Transfer Learning Based on Multi-Sensor Nodes

by Pascal Vorwerk, Jörg Kelleter, Steffen Müller and Ulrich Krause

Proceedings 2024, 97(1), 20; https://doi.org/10.3390/proceedings2024097020 - 14 Mar 2024

Cited by 1 | Viewed by 336

Abstract

Multi-sensor data from a small laboratory setup was used to create a new feature space with linear discriminant analysis (LDA) to improve the classification of different fire materials. The LDA parameters were applied to a real room dataset to evaluate classification models. Data [...] Read more.

Multi-sensor data from a small laboratory setup was used to create a new feature space with linear discriminant analysis (LDA) to improve the classification of different fire materials. The LDA parameters were applied to a real room dataset to evaluate classification models. Data transformation using LDA improved the classification rate by up to 17% compared to principal component analysis (PCA) approaches used in previous studies. Full article

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3 pages, 1638 KiB

Open AccessAbstract

Co₃O₄-Based Materials as Catalysts for Catalytic Gas Sensors

by Olena Yurchenko, Patrick Diehle, Katrin Schmitt and Jürgen Wöllenstein

Proceedings 2024, 97(1), 21; https://doi.org/10.3390/proceedings2024097021 - 14 Mar 2024

Viewed by 360

Abstract

The work deals with the development of Co₃O₄-based catalysts for application in catalytic gas sensors. Among the transition-metal oxide catalysts, cobalt oxide exhibits the highest activity in catalytic combustion. The catalytic activity of the catalysts was examined by Differential [...] Read more.

The work deals with the development of Co₃O₄-based catalysts for application in catalytic gas sensors. Among the transition-metal oxide catalysts, cobalt oxide exhibits the highest activity in catalytic combustion. The catalytic activity of the catalysts was examined by Differential Scanning Calorimetry (DSC), evaluating the catalyst’s activity by measuring its thermal response to 1% methane (CH₄). Full article

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3 pages, 599 KiB

Open AccessAbstract

Development of a Compact, Reliable, and Electrostatically Actuated Device for Microfluidic-Based Active Glasses

by Simon Kulifaj, Clément Chauvin, Antoine Bouvier, Solène Meinier, Fengzhi Gu, Jérôme Degouttes, Nicolas Terrier, Patrick Pittet and Bruno Berge

Proceedings 2024, 97(1), 22; https://doi.org/10.3390/proceedings2024097022 - 14 Mar 2024

Viewed by 306

Abstract

We present the development study of a reliable and low-power actuator for microfluidics-based active glasses. The adaptive part of the lens implements two liquids of a specific refractive index separated by a thin membrane, the modification of their relative volumes allowing adaptive optical [...] Read more.

We present the development study of a reliable and low-power actuator for microfluidics-based active glasses. The adaptive part of the lens implements two liquids of a specific refractive index separated by a thin membrane, the modification of their relative volumes allowing adaptive optical power corrections. The proposed actuator is connected to an adaptive lens by microchannels since it is intended to be installed in the temple of the glasses. The actuation is based on the electrostatic displacement of a thin film, which changes the relative volumes of two cavities filled with these liquids. The metalized film is placed slack with an “S-shape” between two electrodes biased with the actuation voltage. Very compact actuator prototypes have been developed and characterized. Power corrections ranging from +0D to +3D can be achieved via liquid volume displacement as low as 120 µL and with a power consumption of a few mW. The prototypes show good reliability without any significant change in their operation after more than 1 million actuations. For RD purposes, we have replaced some electrodes with transparent windows. With this setup, we show experimental results on the interplay between the performances and the film folding inside the actuator. Full article

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3 pages, 1249 KiB

Open AccessAbstract

Dielectric Spectroscopy for Non-Invasive Sensing of Multi-Layered Organ-on-Chip Devices

by Tim Hosman, Massimo Mastrangeli and Marco Spirito

Proceedings 2024, 97(1), 23; https://doi.org/10.3390/proceedings2024097023 - 14 Mar 2024

Viewed by 315

Abstract

Organ-on-chip (OoC) is emerging as a key technology for improved pre-clinical drug testing. Monitoring tissues and the artificial microenvironment in OoC devices is critical to recapitulate human physiology; however, sensing is often invasive, superficial, and not continuous over time. This work aims to [...] Read more.

Organ-on-chip (OoC) is emerging as a key technology for improved pre-clinical drug testing. Monitoring tissues and the artificial microenvironment in OoC devices is critical to recapitulate human physiology; however, sensing is often invasive, superficial, and not continuous over time. This work aims to overcome these issues by proposing dielectric spectroscopy as a non-invasive and time-continuous sensing technique capable of extracting information from multi-layer OoC devices, including distinguishable tissue layers. The presented results set the foundations for this goal by proving this technique’s feasibility, showing excellent correspondence between the experimental and modelled data, and providing design guidelines for application-tailored optimization. Full article

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3 pages, 845 KiB

Open AccessAbstract

Co-Design and Characterization of a Differential Wireless Passive Micro-Electromechanical System Pressure Sensor

by Romain Alcesilas, Jean Claude Bastien, Marc Sansa, Camille Jouvaud, Patrice Rey and Christophe Delaveaud

Proceedings 2024, 97(1), 24; https://doi.org/10.3390/proceedings2024097024 - 15 Mar 2024

Viewed by 390

Abstract

We present a differential wireless passive sensor based on a miniature antenna associated with a MEMS capacitive pressure sensor. In this configuration, a change in the external pressure results in a shift of the antenna resonance frequency and, thus, a variation in the [...] Read more.

We present a differential wireless passive sensor based on a miniature antenna associated with a MEMS capacitive pressure sensor. In this configuration, a change in the external pressure results in a shift of the antenna resonance frequency and, thus, a variation in the antenna Radar Cross Section (RCS) detectable from a distance of a few meters. The MEMS and the antenna are modelled and simulated, and a co-design procedure is developed to optimize their performance. The MEMS are fabricated on a 200-mm technological platform and characterized. A specific setup was conceived to characterize the antenna sensor as a function of pressure in an anechoic chamber. Full article

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3 pages, 582 KiB

Open AccessAbstract

Development of an e-Nose System for the Early Diagnosis of Sepsis in Mechanically Ventilated Patients: A Preliminary Study

by Stefano Robbiani, Aurora Pierantozzi, Louwrina H. te Nijenhuis, Patricia A. C. Specht, Floor A. Harms, Carmen Bax, Willem van Weteringen, Laura Capelli and Raffaele L. Dellacà

Proceedings 2024, 97(1), 26; https://doi.org/10.3390/proceedings2024097026 - 15 Mar 2024

Viewed by 373

Abstract

Sepsis is a severe condition and the major cause of mortality in the ICU. Prompt intervention decreases mortality, and non-invasive systems for early diagnosis in ICU patients are necessary. This work presents a customized e-Nose system based on non-selective chemical sensors for exhaled [...] Read more.

Sepsis is a severe condition and the major cause of mortality in the ICU. Prompt intervention decreases mortality, and non-invasive systems for early diagnosis in ICU patients are necessary. This work presents a customized e-Nose system based on non-selective chemical sensors for exhaled breath analysis. The system comprises two units: a sampling device able to collect exhaled breath from mechanically ventilated patients and an e-Nose in which the gas is analyzed. Preliminary results from a porcine model support the possibility of discriminating between healthy and sepsis subjects. Full article

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3 pages, 818 KiB

Open AccessAbstract

A Cervical Plethysmography System to Monitor Blood Vessel Pulses on the Neck

by Antonino Proto, Anselmo Pagani, Paolo Zamboni and Angelo Taibi

Proceedings 2024, 97(1), 27; https://doi.org/10.3390/proceedings2024097027 - 15 Mar 2024

Viewed by 403

Abstract

A cervical plethysmography system has been developed to monitor blood vessel pulses on the neck area and at the same time to record the electrocardiogram signal. The system was tested on subjects in upright (90°) and supine (0°) position. The proposed cervical plethysmography [...] Read more.

A cervical plethysmography system has been developed to monitor blood vessel pulses on the neck area and at the same time to record the electrocardiogram signal. The system was tested on subjects in upright (90°) and supine (0°) position. The proposed cervical plethysmography system can be used as a biomedical tool for cardiovascular screening in the general population. Full article

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3 pages, 499 KiB

Open AccessAbstract

Develop a Smart Material Based on Carbon-Aramid Hybrid Composite for Health Monitoring Structure

by Khalid Alblalaihid, Saad Aldoihi, Abdulaziz Alharbi, Meshal Abuobaid, Sabri Alkhaibari, Khalid Khormi, Sami Alsaleh, Khaled S. Almutairi and Majid A. Albahkali

Proceedings 2024, 97(1), 28; https://doi.org/10.3390/proceedings2024097028 - 15 Mar 2024

Viewed by 380

Abstract

This paper discusses the use of Kevlar-carbon hybrid composites in the aerospace industry for structural and non-structural components. By combining the high tensile strength and impact resistance of Kevlar fibers with the high stiffness and dimensional stability of carbon fibers, a material with [...] Read more.

This paper discusses the use of Kevlar-carbon hybrid composites in the aerospace industry for structural and non-structural components. By combining the high tensile strength and impact resistance of Kevlar fibers with the high stiffness and dimensional stability of carbon fibers, a material with enhanced mechanical properties can be achieved. However, the combination of two materials with different properties can cause delamination between layers, making real-time monitoring of structural integrity important. This study investigates the feasibility of embedding sensors into Kevlar-carbon hybrid composites and presents the basic characterization using a mechanical tensile test. It been shown the embedded sensor has a linear response toward the axial stress and the damage can be detected at the turning point where the capacitance begins to decrease. Full article

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3 pages, 808 KiB

Open AccessAbstract

A Low-Cost, Self-Powered, Plantar Pressure Distribution Sensing Insole

by Abdo-Rahmane Anas Laaraibi, Gurvan Jodin, Mario Costanza, Damien Hoareau, Samuel Margueron, Nicolas Bideau and Florence Razan

Proceedings 2024, 97(1), 29; https://doi.org/10.3390/proceedings2024097029 - 15 Mar 2024

Viewed by 372

Abstract

Energy-autonomous wireless sensors are a promising solution for developing wearable medical, lifestyle- and performance-monitoring systems. This paper presents a low-cost, low-power and self-powered wearable intelligent pressure monitoring system based on flexible piezoresistive sensors. The encapsulated insole with an 8 × 2 sensor matrix [...] Read more.

Energy-autonomous wireless sensors are a promising solution for developing wearable medical, lifestyle- and performance-monitoring systems. This paper presents a low-cost, low-power and self-powered wearable intelligent pressure monitoring system based on flexible piezoresistive sensors. The encapsulated insole with an 8 × 2 sensor matrix is powered by a flexible solar panel and connected to a rigid electronic board. Data acquisition occurs via Bluetooth low-energy transmission (BLE), and the average power consumption of the insole is 113 µW. Full article

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3 pages, 356 KiB

Open AccessAbstract

Development of NOx Gas Sensor Based on Electrospun ZnO Nanofibers for Diagnosing Asthma Disease

by Niloufar Khomarloo, Elham Mohsenzadeh, Roohollah Bagherzadeh, Masoud Latifi, Driss Lahem, Ari Hakgor, Ly Ahmadou and Hayriye Gidik

Proceedings 2024, 97(1), 30; https://doi.org/10.3390/proceedings2024097030 - 15 Mar 2024

Viewed by 358

Abstract

Volatile organic compounds (VOCs) have the potential to serve as biomarkers for respiratory diseases such as asthma. Non-invasive respiratory analysis can be used for early detection and disease monitoring. This paper presents the development of a ZnO metal oxide nanofibers sensor as a [...] Read more.

Volatile organic compounds (VOCs) have the potential to serve as biomarkers for respiratory diseases such as asthma. Non-invasive respiratory analysis can be used for early detection and disease monitoring. This paper presents the development of a ZnO metal oxide nanofibers sensor as a cost-effective method for detecting NO, which is an asthma biomarker, and NO₂, that can cause asthma. Electrospun metal oxide nanofibers are considered for gas sensor applications due to their unique structural and electrical properties. The results indicate that the amount of zinc acetate and the morphology of the ZnO nanofibers as a sensing medium can affect the sensitivity of the gas sensor. The preparation of electrospinning solutions containing varying amounts of zinc acetate must be carefully considered due to its impact on morphology and thus sensitivity. Full article

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3 pages, 507 KiB

Open AccessAbstract

A Magnetic Tracking System Featuring Calibrated Three-Axis AMR Sensors

by Thomas Quirin, Corentin Féry, Céline Vergne, Morgan Madec, Luc Hébrard and Joris Pascal

Proceedings 2024, 97(1), 31; https://doi.org/10.3390/proceedings2024097031 - 15 Mar 2024

Viewed by 301

Abstract

This article presents a magnetic tracking system using on-chip anisotropic magnetoresistive (AMR) sensors. The system consists of four air-core coils sequentially generating four dc magnetic fields. The implemented localization algorithm is quadrilateration, and the accuracy of the system is dependent on the accuracy [...] Read more.

This article presents a magnetic tracking system using on-chip anisotropic magnetoresistive (AMR) sensors. The system consists of four air-core coils sequentially generating four dc magnetic fields. The implemented localization algorithm is quadrilateration, and the accuracy of the system is dependent on the accuracy of the sensors and the simulated field maps. The performance of the system was evaluated using an in-house magnetic field camera (MFC), and the results showed that the system exhibits mean Euclidean errors below 1 mm where the source produces strong gradients. Given the dimensions of the sensors (0.82 × 0.82 mm²), this system is suitable for tracking minimally invasive surgical tools. Full article

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3 pages, 701 KiB

Open AccessAbstract

Electropolymerized PEDOT:PSS Thin Films for Fabrication of Vertical Organic Electrochemical Transistors

by Andreas Schander, Michael Skowrons, Melanie Kirsch and Björn Lüssem

Proceedings 2024, 97(1), 32; https://doi.org/10.3390/proceedings2024097032 - 18 Mar 2024

Viewed by 518

Abstract

This paper presents novel vertical organic electrochemical transistors (vOECTs) with thin transistor channels grown by the electropolymerization of the electrically conductive polymer PEDOT:PSS. This new fabrication method avoids the need for the further structuring of the sensitive polymer layers, which will enable the [...] Read more.

This paper presents novel vertical organic electrochemical transistors (vOECTs) with thin transistor channels grown by the electropolymerization of the electrically conductive polymer PEDOT:PSS. This new fabrication method avoids the need for the further structuring of the sensitive polymer layers, which will enable the high-density integration of biosensors, e.g., on neural probes. Full article

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3 pages, 407 KiB

Open AccessAbstract

Enhancing Ozone Monitoring with Low-Cost Sensors and Deep Neural Network: A Novel Approach

by Marco Magoni, Andrea Gaiardo, Matteo Valt, Pietro Tosato, Barbara Fabbri and Vincenzo Guidi

Proceedings 2024, 97(1), 33; https://doi.org/10.3390/proceedings2024097033 - 18 Mar 2024

Viewed by 331

Abstract

Ozone is a crucial component of the Earth’s atmosphere, playing a critical role in protecting the planet from harmful ultraviolet radiation. However, its concentration can vary greatly across different regions with significant impacts on human health and environment equilibrium. The aim of this [...] Read more.

Ozone is a crucial component of the Earth’s atmosphere, playing a critical role in protecting the planet from harmful ultraviolet radiation. However, its concentration can vary greatly across different regions with significant impacts on human health and environment equilibrium. The aim of this work was to calibrate a low-cost sensing platform, based on chemoresistive gas sensors, to monitor the environmental concentration of O₃. The ongoing on-field calibration is performed with a deep neural network using the concentration of O₃ collected by the local environmental protection agencies through certified tools as the gold standard. Full article

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3 pages, 1569 KiB

Open AccessAbstract

Two-Dimensional Localization of an Aluminum Tag Using the Electromagnetic Shielding Effect

by Kiera Montgomery and Kean Chin Aw

Proceedings 2024, 97(1), 34; https://doi.org/10.3390/proceedings2024097034 - 18 Mar 2024

Viewed by 291

Abstract

Electromagnetic shielding is an underutilized method for non-invasive proximity sensing that could be useful in automated production lines as a low-cost method to locate products. A strong relationship was shown between the position of a tag and individual sensors. The strength of the [...] Read more.

Electromagnetic shielding is an underutilized method for non-invasive proximity sensing that could be useful in automated production lines as a low-cost method to locate products. A strong relationship was shown between the position of a tag and individual sensors. The strength of the magnetic field generated by the coil was reduced by up to 25% when the tag was above the sensor and started to decay when the tag was within 15 mm of each sensor. These measurements can then be aggregated to provide a greater range of measurement. Full article

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3 pages, 327 KiB

Open AccessAbstract

Energy-Harvesting Smart Tiles for Human–Machine Interface Applications

by Alessandro Zompanti, Paolo Romeo, Anna Sabatini, Luca Vollero, Marco Santonico and Giorgio Pennazza

Proceedings 2024, 97(1), 35; https://doi.org/10.3390/proceedings2024097035 - 18 Mar 2024

Viewed by 312

Abstract

In this work, a human–machine interface with energy harvesting capabilities was developed and a modular floor made of tiles equipped with piezoelectric elements was produced. The developed platform was tested as a position-tracking system for a human user, allowing the tracking of the [...] Read more.

In this work, a human–machine interface with energy harvesting capabilities was developed and a modular floor made of tiles equipped with piezoelectric elements was produced. The developed platform was tested as a position-tracking system for a human user, allowing the tracking of the lower body in a virtual reality environment. Moreover, the energy collected by the device was evaluated. Full article

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3 pages, 499 KiB

Open AccessAbstract

Development and Deployment of Portable Sensor Platforms Based on a Micro-Electro-Mechanical-System Chemoresistive Gas Sensor Array for Outdoor Air Quality Monitoring

by Andrea Gaiardo, Matteo Valt, Pietro Tosato, Marco Magoni, Vincenzo Guidi, Claudia Dolci and Pierluigi Bellutti

Proceedings 2024, 97(1), 36; https://doi.org/10.3390/proceedings2024097036 - 18 Mar 2024

Viewed by 357

Abstract

Nowadays, there is a growing demand for a well-distributed sensor network to monitor air quality which can aid policymakers in making decisions. This has led to an increase in the R&D of cost-effective and energy-efficient sensing solutions. In this study, sensing platforms composed [...] Read more.

Nowadays, there is a growing demand for a well-distributed sensor network to monitor air quality which can aid policymakers in making decisions. This has led to an increase in the R&D of cost-effective and energy-efficient sensing solutions. In this study, sensing platforms composed of MEMS chemoresistive gas sensors were developed and deployed in two Italian cities for the detection of pollutants. Over three years of measurements, the sensors have proven to be reliable in detecting CO, NO₂ and O₃ with high accuracy compared to data collected by local environmental protection agencies, paving the way for their potential validation and future adoption. Full article

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3 pages, 145 KiB

Open AccessAbstract

Efficient Methods for Training and Validation of Odor Sensors

by Gina Zeh, Maximilian Koehne and Tilman Sauerwald

Proceedings 2024, 97(1), 37; https://doi.org/10.3390/proceedings2024097037 - 18 Mar 2024

Viewed by 344

Abstract

The correlation between a gas sensor pattern and its corresponding odor impression on human noses remains a scientific challenge for the development of technical odor detection systems. Small, inexpensive gas sensors, for example, those based on a metal oxide semiconductor (MOS), offer a [...] Read more.

The correlation between a gas sensor pattern and its corresponding odor impression on human noses remains a scientific challenge for the development of technical odor detection systems. Small, inexpensive gas sensors, for example, those based on a metal oxide semiconductor (MOS), offer a versatile platform for the development of application-specific sensor systems for odor detection or monitoring. The training of MOS sensors for odor detection remains a challenging task that has been addressed by recent advances. We hereby present a comprehensive method and instrumentation for the characterization and validation of MOS sensors using a gas chromatograph with a mass spectrometer and odor detection port. Full article

3 pages, 1088 KiB

Open AccessAbstract

A Low-Cost Solution and Continuous Wavelet Transform Analysis for Structural Health Monitoring

by Bruno Andò, Danilo Greco and Giacomo Navarra

Proceedings 2024, 97(1), 38; https://doi.org/10.3390/proceedings2024097038 - 18 Mar 2024

Viewed by 335

Abstract

In this paper, a low-cost solution for Structural Health Monitoring is proposed, exploiting a dedicated embedded sensing system. Signals provided by the sensor node have been processed by Continuous Wavelet Transform. The node behavior to seismic-like solicitations and has been assessed in the [...] Read more.

In this paper, a low-cost solution for Structural Health Monitoring is proposed, exploiting a dedicated embedded sensing system. Signals provided by the sensor node have been processed by Continuous Wavelet Transform. The node behavior to seismic-like solicitations and has been assessed in the case of frequency sweeps. The results demonstrate the system’s suitability for use in Early Warning frameworks. Full article

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2 pages, 445 KiB

Open AccessAbstract

Electrochemical Performance of WS₂-CNT Core–Shell Heterostructures for the Detection of Vitamin B₂

by Rayhane Zribi, Muhammad Hamid Raza, Nicola Pinna and Giovanni Neri

Proceedings 2024, 97(1), 39; https://doi.org/10.3390/proceedings2024097039 - 18 Mar 2024

Viewed by 352

Abstract

In this study, a novel electrochemical sensor was developed for the quantitative determination of riboflavin. The tungsten disulfide (WS₂) layer was deposited on carbon nanotubes (CNTs) by atomic layer deposition (ALD), forming a CNTs-WS₂ core–shell heterostructure. This material was used [...] Read more.

In this study, a novel electrochemical sensor was developed for the quantitative determination of riboflavin. The tungsten disulfide (WS₂) layer was deposited on carbon nanotubes (CNTs) by atomic layer deposition (ALD), forming a CNTs-WS₂ core–shell heterostructure. This material was used to modify the commercial screen-printed carbon electrode in order to enhance its electrocatalytic activity toward the detection of vitamin B₂. Cyclic voltammetry was performed as a preliminary test in the presence of riboflavin. In addition to this, an extensive electrochemical study was performed using differential pulse voltammetry, demonstrating that modified the CNTs-WS₂/SPCE sensor display superior electrochemical performance compared with bare SPCE. The sensor exhibits a linear response in the concentration range from 0 µM to 45 µM, with remarkably enhanced sensitivity (9 μAμM⁻¹cm⁻²) compared with the bare electrode, with a limit of detection (LOD) of 1.24 µM. This enhancement is attributed to the conformal growth of the WS2 flakes on the CNTs and the high surface area offered by these flakes. Full article

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3 pages, 373 KiB

Open AccessAbstract

Experimental Development and Validation of an E-Textile Sleeve for Surface Electromyography

by Armando Coccia, Federica Amitrano, Gaetano Pagano, Arcangelo Biancardi, Giuseppe Tombolini and Giovanni D’Addio

Proceedings 2024, 97(1), 40; https://doi.org/10.3390/proceedings2024097040 - 18 Mar 2024

Viewed by 374

Abstract

This work describes the development of a leg sleeve with embedded e-textile electrodes for surface electromyography (sEMG). The novel device is a textile substrate with embedded circular electrodes made of conductive fabric, which can be connected to EMG acquisition systems. The performances of [...] Read more.

This work describes the development of a leg sleeve with embedded e-textile electrodes for surface electromyography (sEMG). The novel device is a textile substrate with embedded circular electrodes made of conductive fabric, which can be connected to EMG acquisition systems. The performances of the novel prototypical device were validated in comparison with standard sEMG electrodes. The experimental study involved 11 healthy volunteers, and general features extracted from the signals were compared using statistical methods. The results underline the absence of significant differences between the two systems, suggesting that the e-textile novel device is a viable alternative to conventional electrodes for collecting sEMG data. Full article

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3 pages, 3579 KiB

Open AccessAbstract

Concept and Proof of Principle of an Acoustofluidic Single-Particle Sorting Device Using a Spatially Confined Acoustic Active Region

by Andreas Fuchsluger, Annalisa De Pastina, Tina Mitteramskogler, Rafael Ecker, Thomas Voglhuber-Brunnmaier, Nikolai Andrianov, Alexander Shatalov, Norbert Cselyuszka, Mohssen Moridi and Bernhard Jakoby

Proceedings 2024, 97(1), 41; https://doi.org/10.3390/proceedings2024097041 - 18 Mar 2024

Viewed by 367

Abstract

We present the concept and a proof-of-principle experiment for an acoustofluidic single- particle sorter. In a microfluidic channel, a flow profile with the following three parallel fluid domains is generated: buffer fluid in the center and buffer plus particles in the lateral domains. [...] Read more.

We present the concept and a proof-of-principle experiment for an acoustofluidic single- particle sorter. In a microfluidic channel, a flow profile with the following three parallel fluid domains is generated: buffer fluid in the center and buffer plus particles in the lateral domains. Due to the laminar flow regime present in microfluidics, the particles essentially follow the stream line(s) along the channel. In the spatially confined sorting and detection region, by switching on the standing acoustic wave, particles of interest (POIs) are pushed into the center fluid domain, thus leaving the chip at the center outlet. For particles of non-interest (PONIs), the acoustic region remains silent, so PONIs are not centered and follow their path to the side outlet. Full article

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3 pages, 479 KiB

Open AccessAbstract

Fabricating Acetic Acid Sensors Using PVP Nanofibrous Scaffold Doubly Decorated with Mesoporous Graphene

by Paolo Papa, Emiliano Zampetti, Corrado Di Natale, Fabrizio De Cesare, Giovanna Tranfo and Antonella Macagnano

Proceedings 2024, 97(1), 42; https://doi.org/10.3390/proceedings2024097042 - 18 Mar 2024

Viewed by 363

Abstract

A nanofibrous layer of polyvinylpyrrolidone (PVP) was designed to house, both in the fiber core and onto its outer surface, nanoparticles of mesoporous graphene (MGC), which are able to selectively adsorb acetic acid vapors. When grown on interdigital fingers microelectrodes (IDEs), upon UV-light [...] Read more.

A nanofibrous layer of polyvinylpyrrolidone (PVP) was designed to house, both in the fiber core and onto its outer surface, nanoparticles of mesoporous graphene (MGC), which are able to selectively adsorb acetic acid vapors. When grown on interdigital fingers microelectrodes (IDEs), upon UV-light irradiation taking place in air, the layer proved conductive and stable. Electrical and sensing features were significatively modulated by decorating the fiber surface with MGC (a sandwich-like structure) and polyethyleneimine (PEI). MGC, used both as a conductive filler and to decorate the fiber surface, strengthened the PVP scaffold and acted as a nucleation center for entrapping molecules of acetic acid. PEI improved the adhesion of MGC onto the surface. A preliminary study reported fast responses, high sensitivity with good linearity, selectivity, reversibility, and repeatability towards the acetic acid in ranges of up to hundreds of ppm at room temperature. Full article

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3 pages, 1174 KiB

Open AccessAbstract

Equivalent Circuit Models for Impedimetric Sensors

by Eva-Maria Korek, Evanthia Chrysanthi Kounoupioti and Ralf Brederlow

Proceedings 2024, 97(1), 43; https://doi.org/10.3390/proceedings2024097043 - 18 Mar 2024

Viewed by 344

Abstract

In this work, equivalent circuit models for conductivity, reference, and potassium ion sensors are introduced and validated. The models help to understand and verify the sensors’ functioning and to determine the selective element of the potassium sensor as a capacitance that occurs below [...] Read more.

In this work, equivalent circuit models for conductivity, reference, and potassium ion sensors are introduced and validated. The models help to understand and verify the sensors’ functioning and to determine the selective element of the potassium sensor as a capacitance that occurs below 1 Hz. Measurements at 100 mHz suggest that the phase response of the sensor reveals advantages concerning response time and stability compared to the typically used magnitude. Full article

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3 pages, 1347 KiB

Open AccessAbstract

Fabrication of Wafer-Level Vacuum-Packaged 3C-SiC Resonators with Q-Factor above 250,000

by Sergio Sapienza, Luca Belsito, Matteo Ferri, Ivan Elmi, Marcin Zielinski, Francesco La Via and Alberto Roncaglia

Proceedings 2024, 97(1), 44; https://doi.org/10.3390/proceedings2024097044 - 18 Mar 2024

Viewed by 376

Abstract

In this work, the fabrication of wafer-level vacuum-packaged 3C-SiC on Si double- clamped beam resonators via glass–silicon anodic bonding using Ti-based vacuum gettering is reported. Open-loop resonance measurements are performed on the vacuum-packaged devices, showing Q-factor values up to 290,000, a process yield [...] Read more.

In this work, the fabrication of wafer-level vacuum-packaged 3C-SiC on Si double- clamped beam resonators via glass–silicon anodic bonding using Ti-based vacuum gettering is reported. Open-loop resonance measurements are performed on the vacuum-packaged devices, showing Q-factor values up to 290,000, a process yield above 80%, and a maximum vacuum level around 10⁻² mbar inside the Ti-gettered encapsulations. Full article

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3 pages, 497 KiB

Open AccessAbstract

Electrochemical Sensors for Animal Welfare

by Ilaria Sorrentino, Claire Verplanck and Yohann R. J. Thomas

Proceedings 2024, 97(1), 45; https://doi.org/10.3390/proceedings2024097045 - 18 Mar 2024

Viewed by 331

Abstract

The WAIT4 (Welfare: Artificial Intelligence and new Technologies for Tracking Key Indicator Traits in Animals Facing Challenges of the Agro-ecological Transition) project aims to increase research-based capacities to quantify and characterize animal welfare (AW) from the agro-ecological (AE) perspective and to revise farming [...] Read more.

The WAIT4 (Welfare: Artificial Intelligence and new Technologies for Tracking Key Indicator Traits in Animals Facing Challenges of the Agro-ecological Transition) project aims to increase research-based capacities to quantify and characterize animal welfare (AW) from the agro-ecological (AE) perspective and to revise farming practices by considering interactions between the animal and its environment. From this perspective, the development of new sensors for assessing the kinetics of physiological variables of interest (Na⁺, K⁺, pH) in animals’ interstitial fluid (ISF) by microneedle patches will be a valuable aid for farmers to monitoring AW states and various stressors. Full article

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3 pages, 322 KiB

Open AccessAbstract

A Chipless RFID Humidity Sensor for Smart Packaging Applications

by Viviana Mulloni, Giada Marchi, Andrea Gaiardo, Matteo Valt, Massimo Donelli and Leandro Lorenzelli

Proceedings 2024, 97(1), 46; https://doi.org/10.3390/proceedings2024097046 - 18 Mar 2024

Viewed by 292

Abstract

A chipless RFID humidity sensor suitable for smart packaging is proposed in this work. The sensor is flexible, fast, low-cost, easy to fabricate and can be read wirelessly. The results show a very high sensitivity in the low-humidity range (1–10%), making it especially [...] Read more.

A chipless RFID humidity sensor suitable for smart packaging is proposed in this work. The sensor is flexible, fast, low-cost, easy to fabricate and can be read wirelessly. The results show a very high sensitivity in the low-humidity range (1–10%), making it especially suited to monitor and establish package integrity. Full article

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3 pages, 323 KiB

Open AccessAbstract

WO3-Pt/Graphene Nanocomposite Sensors for Methane Sensing Applications

by Patricia Arroyo, Tiziana Polichetti, Brigida Alfano, Maria Lucia Miglietta, Ettore Massera and Jesus Lozano

Proceedings 2024, 97(1), 47; https://doi.org/10.3390/proceedings2024097047 - 18 Mar 2024

Viewed by 326

Abstract

This study presents the fabrication and characterization of chemoresistive sensors based on a nanocomposite of WO3-Pt and graphene for methane detection. The graphene was prepared using a liquid-phase exfoliation technique, and the nanocomposite was deposited onto interdigitated gold electrodes using drop-casting. The response [...] Read more.

This study presents the fabrication and characterization of chemoresistive sensors based on a nanocomposite of WO3-Pt and graphene for methane detection. The graphene was prepared using a liquid-phase exfoliation technique, and the nanocomposite was deposited onto interdigitated gold electrodes using drop-casting. The response of the sensors was analyzed by measuring changes in electrical resistance at methane concentrations of 7, 5, 3, and 1 ppm. Full article

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3 pages, 416 KiB

Open AccessAbstract

Fabrication of an Ultrathin PMMA Foil for Sensing Applications in Microfluidic Systems

by Rafael Ecker, Tina Mitteramskogler, Andreas Fuchsluger and Bernhard Jakoby

Proceedings 2024, 97(1), 48; https://doi.org/10.3390/proceedings2024097048 - 19 Mar 2024

Viewed by 356

Abstract

This research work focuses on the fabrication of ultrathin polymethylmethacrylate (PMMA) foils using a spin coating process of in anisole dissolved PMMA on a water-soluble polyvinyl alcohol (PVA) foil. Currently, layer thicknesses as low as 1 µm can be achieved and even thinner [...] Read more.

This research work focuses on the fabrication of ultrathin polymethylmethacrylate (PMMA) foils using a spin coating process of in anisole dissolved PMMA on a water-soluble polyvinyl alcohol (PVA) foil. Currently, layer thicknesses as low as 1 µm can be achieved and even thinner layers appear to be possible. Sensors and actuators can be applied to the foils and directly integrated into the center of the channel of a polymer-based microfluidic chip. Specifically, the foil acts as a supporting structure that helps to position the sensor in the center of the channel. Thermal sensors, in particular, benefit from the low heat capacity of the foil. This will improve the performance and the accuracy of these sensors of which the impact on the fluidic flow is minimized. Full article

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3 pages, 456 KiB

Open AccessAbstract

A Wireless Strain Sensor for Measurement in Composites

by Lukas Bertram, Michael Brink and Walter Lang

Proceedings 2024, 97(1), 49; https://doi.org/10.3390/proceedings2024097049 - 19 Mar 2024

Viewed by 386

Abstract

This paper presents first characterization results of a novel, battery-less sensor for integration into glass fiber-reinforced plastic (FRP) materials. The sensor targets combined usage in both production and structural health monitoring applications. It is shown that wireless measurement of biaxial mechanical strain inside [...] Read more.

This paper presents first characterization results of a novel, battery-less sensor for integration into glass fiber-reinforced plastic (FRP) materials. The sensor targets combined usage in both production and structural health monitoring applications. It is shown that wireless measurement of biaxial mechanical strain inside FRP is possible with the presented approach. The results promise feasibility of industrial application by implementing a sticker-based ‘sensor tag’ approach for easy application and additional advantages in context of ‘smart’ structures. Full article

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3 pages, 988 KiB

Open AccessAbstract

An Acoustically Transparent Electrical Cap for Piezoelectric Ultrasound Transducers on Silicon

by Gandhika K. Wardhana, Tiago L. Costa and Massimo Mastrangeli

Proceedings 2024, 97(1), 50; https://doi.org/10.3390/proceedings2024097050 - 19 Mar 2024

Viewed by 415

Abstract

Bulk piezoelectric ultrasound transducers on integrated circuits offer unique properties for therapeutic applications of ultrasound neuromodulation. However, current implementations of such transducers are not optimized for the high transmit efficiency required to stimulate neurons. This is mainly due to the challenge of implementing [...] Read more.

Bulk piezoelectric ultrasound transducers on integrated circuits offer unique properties for therapeutic applications of ultrasound neuromodulation. However, current implementations of such transducers are not optimized for the high transmit efficiency required to stimulate neurons. This is mainly due to the challenge of implementing a metal layer on top of the piezoelectric film using microfabrication techniques. Here, we propose a micromachined capping structure providing an electrical connection on top of the piezoelectric film with minimal acoustic losses. The structure can potentially be used as a common ground connection in phased-array ultrasound transducers. Full article

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3 pages, 942 KiB

Open AccessAbstract

A Phenylalanine Ammonia Lyase Capacitive Sensor for Phenylalanine Detection

by Bruno Andò, Salvatore Castorina, Ludovica Maugeri, Salvatore Petralia, Maria Anna Messina, Martino Ruggieri, Giovanni Neri, Angelo Ferlazzo, Emilio Sardini and Mauro Serpelloni

Proceedings 2024, 97(1), 51; https://doi.org/10.3390/proceedings2024097051 - 19 Mar 2024

Viewed by 408

Abstract

In this paper, an easy-to-use and fast biosensor for phenylalanine quantification in patients affected by phenylketonuria is investigated. The phenylalanine concentration was indirectly estimated through the ammonia released as a by-product of an enzymatic reaction, which was then detected by exploiting an yttria-stabilized [...] Read more.

In this paper, an easy-to-use and fast biosensor for phenylalanine quantification in patients affected by phenylketonuria is investigated. The phenylalanine concentration was indirectly estimated through the ammonia released as a by-product of an enzymatic reaction, which was then detected by exploiting an yttria-stabilized zirconia layer deposited over an interdigitated capacitive sensor. The latter was manufactured by rapid-prototyping technologies. A sensor limit of detection higher than 1.25 µM was estimated, along with an accuracy better than 18.31 µM. Full article

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4 pages, 693 KiB

Open AccessAbstract

Additive Manufacturing Electronics for Packaging High-Frequency Aluminum Nitride Piezoelectric Micromachined Ultrasonic Transducer Probes

by Vincenzo Mariano Mastronardi, Antonio Qualtieri, Enrico Boni, Piero Tortoli, Roberto De Fazio, Paolo Visconti, Maria Teresa Todaro and Massimo De Vittorio

Proceedings 2024, 97(1), 52; https://doi.org/10.3390/proceedings2024097052 - 18 Mar 2024

Viewed by 357

Abstract

Additive Manufacturing Electronics (AME) is a promising method that has the potential to directly embed piezoelectric micromachined ultrasonic transducer (PMUT) probes into conventional electronic circuits and boards. It enables fast customized prototyping, three-dimensional circuit boards, and small-series production. In this study, annular probes [...] Read more.

Additive Manufacturing Electronics (AME) is a promising method that has the potential to directly embed piezoelectric micromachined ultrasonic transducer (PMUT) probes into conventional electronic circuits and boards. It enables fast customized prototyping, three-dimensional circuit boards, and small-series production. In this study, annular probes composed of circular suspended Aluminum Nitride (AlN)-based PMUT membranes, addressed in 2-dimensional arrays, were designed, fabricated, and encapsulated using AME technology. Full article

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3 pages, 896 KiB

Open AccessAbstract

Aerosol Measurements by OPC Aided by QCM Mass Sensor

by Emiliano Zampetti, Maria Aurora Mancuso, Papa Paolo, Antonella Macagnano, Andrea Bearzotti and Yi Hsuan Chen

Proceedings 2024, 97(1), 53; https://doi.org/10.3390/proceedings2024097053 - 19 Mar 2024

Viewed by 358

Abstract

Atmospheric aerosols, as well as particulate matters or suspended particulate matters (PMx), impact climate and affect human health, directly or indirectly. PMx is one of the most important pollutants monitored for air quality evaluation. Optical particle counters and quartz crystal microbalances are used [...] Read more.

Atmospheric aerosols, as well as particulate matters or suspended particulate matters (PMx), impact climate and affect human health, directly or indirectly. PMx is one of the most important pollutants monitored for air quality evaluation. Optical particle counters and quartz crystal microbalances are used to measure mass in a fixed volume. However, when used separately, these devices can show some issues. In this work, we propose combining these devices to obtain results that include particle counting, mass measurement, and, in particular cases, discrimination between solid and liquid aerosols. By using both instruments together, we can overcome the limitations of each and obtain more accurate and comprehensive data on air quality. Full article

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3 pages, 798 KiB

Open AccessAbstract

Enhancing Ammonia Sensor Sensitivity by CuBr Encapsulation in a Mesoporous Host

by Lisa Weber, Virginie Martini, David Grosso, Stephane Burtey and Marc Bendahan

Proceedings 2024, 97(1), 54; https://doi.org/10.3390/proceedings2024097054 - 19 Mar 2024

Viewed by 402

Abstract

A resistive room-temperature ammonia sensor has been developed by CuBr impregnation of a mesoporous SiO₂ host prepared by the sol–gel process and deposited by dip-coating. The mesoporous sensor performances are compared with those of a single CuBr layer. The CuBr encapsulation in [...] Read more.

A resistive room-temperature ammonia sensor has been developed by CuBr impregnation of a mesoporous SiO₂ host prepared by the sol–gel process and deposited by dip-coating. The mesoporous sensor performances are compared with those of a single CuBr layer. The CuBr encapsulation in a mesoporous host leads to an impressive sensitivity improvement with sub-ppm detection of ammonia at room temperature. The results open new perspectives for the development of highly sensitive chemical sensors and are of great interest for non-invasive health monitoring. Full article

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3 pages, 595 KiB

Open AccessAbstract

Three-Dimensionally Printed Resonator with Piezoelectric Actuation and Machine Learning Calibration for In-Line Density–Viscosity Sensing

by Víctor Corsino, Víctor Ruiz-Díez, Mario Ramírez-Palma, Javier Toledo, José Manuel Gilpérez and José Luis Sánchez-Rojas

Proceedings 2024, 97(1), 55; https://doi.org/10.3390/proceedings2024097055 - 19 Mar 2024

Viewed by 396

Abstract

Three-dimensionally printed cuboid-shaped flow cells featuring a rectangular vibrating plate in one of the sides, actuated by PZT piezoelectric films, were designed, fabricated, and tested. Instead of oscillator circuits based on single resonances, we use the frequency response of the cell in a [...] Read more.

Three-dimensionally printed cuboid-shaped flow cells featuring a rectangular vibrating plate in one of the sides, actuated by PZT piezoelectric films, were designed, fabricated, and tested. Instead of oscillator circuits based on single resonances, we use the frequency response of the cell in a range with multiple resonances, sensitive to the liquid properties. Machine learning techniques were implemented for training and calibration with water–glycerol mixtures at different temperatures. Various materials, fabrication parameters, and post-treatment processes were investigated. The calibration errors and resolutions are compared for different devices, conditioning circuits, and machine learning algorithms. Our results demonstrate the high potential of the low-cost sensor to monitor density and viscosity in aqueous solutions. Full article

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3 pages, 460 KiB

Open AccessAbstract

Fabrication of 3D Nanostructures via AFM-Based Nanolithography

by Lorenzo Vincenti, Paolo Pellegrino, Isabella Farella, Mariafrancesca Cascione, Valeria De Matteis, Fabio Quaranta and Rosaria Rinaldi

Proceedings 2024, 97(1), 56; https://doi.org/10.3390/proceedings2024097056 - 19 Mar 2024

Viewed by 390

Abstract

The increasing use of nanomaterials in high-tech devices has posed an exciting challenge for the scientific community to develop new, easy, high-throughput nanofabrication approaches. Here, we present an easy AFM-based nanofabrication approach based on Static Plowing Lithography, with which we are able to [...] Read more.

The increasing use of nanomaterials in high-tech devices has posed an exciting challenge for the scientific community to develop new, easy, high-throughput nanofabrication approaches. Here, we present an easy AFM-based nanofabrication approach based on Static Plowing Lithography, with which we are able to realize patterns of 3D nanostructures on a thin PMMA layer. By coupling a wet etching process with ultrasound exposure, we effectively removed the polymer bulges at the nanostructure’s borders, increasing the quality of the patterned 3D nanostructures, and paving the way for their integration into lab-on-a-chip devices. Full article

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3 pages, 463 KiB

Open AccessAbstract

Electrochemical Detection of MMP-2 Using Graphene-Based Aptasensor

by Stefan Jarić, Silvia Schobesberger, Peter Ertl, Nikola Ž. Knežević and Ivan Bobrinetskiy

Proceedings 2024, 97(1), 57; https://doi.org/10.3390/proceedings2024097057 - 19 Mar 2024

Viewed by 394

Abstract

A graphene-based electrochemical biosensor was developed for the detection of matrix metalloproteinase 2 (MMP-2) endopeptidase, whose expression can be significantly related to the occurrence, metastasis, and prognosis of cancer. A specific anti-MMP-2 aptamer was successfully immobilized on the surface of electrochemically reduced graphene [...] Read more.

A graphene-based electrochemical biosensor was developed for the detection of matrix metalloproteinase 2 (MMP-2) endopeptidase, whose expression can be significantly related to the occurrence, metastasis, and prognosis of cancer. A specific anti-MMP-2 aptamer was successfully immobilized on the surface of electrochemically reduced graphene oxide via a pyrene-based linker, enabling the specific capture of MMP-2. The sensor was able to detect 1 ng mL⁻¹, with an overall detection time of less than 20 min. Moreover, the aptamer-based biosensor showed good specificity toward different unspecific proteins. Full article

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3 pages, 1023 KiB

Open AccessAbstract

Contactless Heating Technology for Lab-on-Chip Microfluidic-Based Nucleic Acid Amplification Testing System

by Tomasz Matusiak, Miron Tokarski, Małgorzata Małodobra-Mazur, Henryk Roguszczak, Arkadiusz Dąbrowski, Paweł Sitarz and Matylda Czosnykowska

Proceedings 2024, 97(1), 58; https://doi.org/10.3390/proceedings2024097058 - 20 Mar 2024

Viewed by 379

Abstract

The miniaturisation of manual systems is reported in this paper. The whole system was based on microfluidic cartridge heated up by a unique contactless system. The presented device utilised fully passive cartridge with required reagents. Full article

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3 pages, 635 KiB

Open AccessAbstract

Research by Fondazione Bruno Kessler on Strategies to Improve the Yield in Plasma Focused Ion Beam Circuit Editing

by David Novel, Evgeny Demenev and Lorenza Ferrario

Proceedings 2024, 97(1), 59; https://doi.org/10.3390/proceedings2024097059 - 20 Mar 2024

Viewed by 380

Abstract

This contribution explores the potential of PFIB for the post-production circuit editing of custom ASICs. The reworking of integrated circuits with ion beam is an effective tool for testing design modifications rapidly, and in small-volume productions, it proves to be a valuable substitute [...] Read more.

This contribution explores the potential of PFIB for the post-production circuit editing of custom ASICs. The reworking of integrated circuits with ion beam is an effective tool for testing design modifications rapidly, and in small-volume productions, it proves to be a valuable substitute for the microfabrication of chips with a revised layout, thus reducing the cost and lead time. In the case study in this work, the PFIB intervention resulted in the recovery of ~90% of defective channels in a multichannel ASIC design by disconnecting some parts of the internal circuit. This contribution describes several implemented optimization strategies and their statistical effectiveness. Full article

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3 pages, 417 KiB

Open AccessAbstract

Efficient Modeling of Piezoelectric Micromachined Ultrasonic Transducers Using a Combination of Finite and Lumped Element Modeling

by Romain Liechti, Francois Blard, Jean-Rémi Chatroux, Jean-Claude Bastien, Hélène Lhermet and Bruno Fain

Proceedings 2024, 97(1), 60; https://doi.org/10.3390/proceedings2024097060 - 20 Mar 2024

Viewed by 363

Abstract

This research paper presents a comprehensive methodology for the efficient modeling of piezoelectric micromachined ultrasonic transducers (PMUTs) using a combination of finite and lumped element models. A single membrane is first studied in air with an eigenfrequency study in order to calibrate the [...] Read more.

This research paper presents a comprehensive methodology for the efficient modeling of piezoelectric micromachined ultrasonic transducers (PMUTs) using a combination of finite and lumped element models. A single membrane is first studied in air with an eigenfrequency study in order to calibrate the lumped element model on the finite element model. From this electrical equivalent circuit, a complete model of the PMUT cell composed of numerous membranes is developed using the propagation, directivity, absorption, mutual and self-impedances, and variability of the resonance frequencies due to manufacturing discrepancies. The calculated acoustic response of the PMUT is then compared with a measured response, in water. The relatively good agreement between the simulation and the measurement, as well as the very low computation time, makes this approach relevant for further optimization of the PMUT design to target larger bandwidth and higher sensitivity. Full article

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3 pages, 2446 KiB

Open AccessAbstract

Annealed Gallium-Doped Zinc Oxide (ZnO:Ga) Thin Films for Sub-ppm NO₂ Sensing

by Benjamin Paret, Philippe Menini, Thierry Camps, Yohann Thimont, Antoine Barnabé, Laurent Mazenq and Lionel Presmanes

Proceedings 2024, 97(1), 61; https://doi.org/10.3390/proceedings2024097061 - 20 Mar 2024

Viewed by 313

Abstract

In this work, gallium-doped zinc oxide was deposited with a Radio Frequency Magnetron sputtering method on test platforms. The NO₂ sensing properties of the resulting devices were studied. The sensing properties of ZnO:Ga thin films were successfully stabilized through annealing in dry [...] Read more.

In this work, gallium-doped zinc oxide was deposited with a Radio Frequency Magnetron sputtering method on test platforms. The NO₂ sensing properties of the resulting devices were studied. The sensing properties of ZnO:Ga thin films were successfully stabilized through annealing in dry air, and then improved by either a thinning of the layer or an increase in the roughness of the substrate. The sensing response with an Rgas/Rair of 15 for 100 ppb of NO₂ under 50% humidity was obtained, with a response time below 10 min. Full article

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3 pages, 751 KiB

Open AccessAbstract

A Low-Cost Testbed for Neural Microelectrodes

by Cat-Vu H. Bui, Neethu Maliakal, Hasan Ulusan, Andreas Hierlemann and Fernando Cardes

Proceedings 2024, 97(1), 62; https://doi.org/10.3390/proceedings2024097062 - 21 Mar 2024

Viewed by 377

Abstract

The performances of microelectrode arrays for neural interfaces strongly depend on electrode design. Due to a lack of simulation tools, electrode engineers often have to refine new designs empirically. This process requires setups of electrical and electrophysiological hardware that are not specific to [...] Read more.

The performances of microelectrode arrays for neural interfaces strongly depend on electrode design. Due to a lack of simulation tools, electrode engineers often have to refine new designs empirically. This process requires setups of electrical and electrophysiological hardware that are not specific to electrode testing and unnecessarily costly. We propose a low-cost testbed for specifically targeting metrics relevant to electrode performance and functions, which relies on an off-the-shelf measurement tool and only on components necessary for such testing. We experimentally demonstrate the platform by characterizing microelectrodes by means of impedance spectroscopy and recording the extracellular action potentials from in vitro primary rat neurons. Full article

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3 pages, 654 KiB

Open AccessAbstract

Laser-Induced Graphitization of Polyimide Tape as Modifiable Sensor in Anodic Stripping Voltammetry

by Laura Chirivì, Antonio Serra, Antonio Della Torre, Riccardo Di Corato, Rosaria Rinaldi and Alessandra Aloisi

Proceedings 2024, 97(1), 63; https://doi.org/10.3390/proceedings2024097063 - 21 Mar 2024

Viewed by 433

Abstract

The monitoring of toxic contaminant traces in the environment needs a simple and sensitive method, such as stripping analysis that applies a pre-concentration step to the analyte on the working electrode. The present work focuses on the realization of a two-electrode sensor made [...] Read more.

The monitoring of toxic contaminant traces in the environment needs a simple and sensitive method, such as stripping analysis that applies a pre-concentration step to the analyte on the working electrode. The present work focuses on the realization of a two-electrode sensor made by means of laser-induced graphitization of a polyimide (PI) tape. Moreover, taking advantage of the strong affinity of Bi for metal ions for detection by Anodic Stripping Voltammetry (ASV), the proposed sensor implementation involved the use of Bi₂O₃ nanopowder as the precursor of Bi film as eco-friendly Hg substitute. Physicochemical analyses were conducted to investigate elemental and structural differences in relation to the shifts recorded in the voltametric behavior. Full article

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3 pages, 743 KiB

Open AccessAbstract

Microfluidic Flowmeter Using a Single Hot Wire

by Rafael Ecker and Bernhard Jakoby

Proceedings 2024, 97(1), 64; https://doi.org/10.3390/proceedings2024097064 - 21 Mar 2024

Viewed by 364

Abstract

The objective of this study is the design and fabrication of a microfluidic thermal flow sensor using polymethylmethacrylate (PMMA) as a substrate. This enables the simple fabrication process of the channel structure and the sensor itself using a laser engraver/cutter machine and a [...] Read more.

The objective of this study is the design and fabrication of a microfluidic thermal flow sensor using polymethylmethacrylate (PMMA) as a substrate. This enables the simple fabrication process of the channel structure and the sensor itself using a laser engraver/cutter machine and a solvent-based bonding process. A thin platinum wire called a Wollaston wire is directly integrated into the fluidic chip and acts as the only sensor element. The combination of this sensor and customized measurement electronics enables a measurement range at flow velocities from 4 mm/s up to 400 mm/s (volume flow rate range from 10 µL/min up to 1 mL/min). Full article

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3 pages, 1348 KiB

Open AccessAbstract

Innovative Silicon-Based Sensing Strategy for the Alzheimer’s Disease Detection by Phage Display

by Paolo Calorenni, Maria Giovanna Rizzo, Laura Maria De Plano, Antonio A. Leonardi, Vincenzo Paratore, Guglielmo Guido Condorelli, Alessia Irrera, Emanuele L. Sciuto, Salvatore Oddo and Sabrina Conoci

Proceedings 2024, 97(1), 65; https://doi.org/10.3390/proceedings2024097065 - 21 Mar 2024

Viewed by 378

Abstract

An innovative biosensing strategy for the diagnosis of Alzheimer’s disease (AD) in human sera has been developed. The technology relied on a silicon flat substrate that was functionalized to perform a phage display detection of anti-amyloid beta (Aβ) antibodies, as AD markers, among [...] Read more.

An innovative biosensing strategy for the diagnosis of Alzheimer’s disease (AD) in human sera has been developed. The technology relied on a silicon flat substrate that was functionalized to perform a phage display detection of anti-amyloid beta (Aβ) antibodies, as AD markers, among the pool of IgGs of human sera. The substrate was derivatized with an interface able to bind and orient the IgGs for the detection operated by an engineered selective probe phage. The interface chemistry and its discrimination activity of healthy and AD sera have been fully characterized. Full article

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3 pages, 614 KiB

Open AccessAbstract

Neural Network Approaches for Distributional Shifts in Environmental Sensors

by Tobias Sukianto, Sebastian A. Schober, Cecilia Carbonelli, Simon Mittermaier and Robert Wille

Proceedings 2024, 97(1), 66; https://doi.org/10.3390/proceedings2024097066 - 21 Mar 2024

Viewed by 386

Abstract

Harmful pollutants in the air have become a severe concern in our health-conscious society. Consequently, deploying low-cost environmental sensors and the application of machine learning algorithms to the sensor raw data are crucial to enabling an overall assessment of the air quality around [...] Read more.

Harmful pollutants in the air have become a severe concern in our health-conscious society. Consequently, deploying low-cost environmental sensors and the application of machine learning algorithms to the sensor raw data are crucial to enabling an overall assessment of the air quality around us. Due to the distributional shift between the training and operational environment induced by sensor ageing and drift processes, the algorithms that predict air quality suffer from performance degradation during the products’ lifetime. We propose a novel transformer-based model architecture inspired by the field of natural language processing, showing advantages compared to other architectures in the presence of distributional shifts. Full article

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3 pages, 409 KiB

Open AccessAbstract

HyperTaste Lab—A Notebook with a Machine Learning Pipeline for Chemical Sensor Arrays

by Gianmarco Gabrieli, Michal Muszynski, Matteo Manica, Joris Cadow-Gossweiler and Patrick W. Ruch

Proceedings 2024, 97(1), 67; https://doi.org/10.3390/proceedings2024097067 - 21 Mar 2024

Viewed by 374

Abstract

The cross-sensitivity of materials in low-selective sensor arrays, namely e-noses and e-tongues, results in a convoluted sensor array response, which renders traditional analytical methods for data processing ineffective. Machine learning approaches can help discover the latent information in such data, and various data [...] Read more.

The cross-sensitivity of materials in low-selective sensor arrays, namely e-noses and e-tongues, results in a convoluted sensor array response, which renders traditional analytical methods for data processing ineffective. Machine learning approaches can help discover the latent information in such data, and various data processing methods, including unsupervised and supervised techniques, have been proposed to calibrate those devices. In this study, we demonstrate HyperTaste Lab—a notebook with a machine learning pipeline for potentiometric sensor arrays. The ability of the notebook to process raw data produced by model sensor arrays comprising cross-sensitive and/or ion-selective electrodes is demonstrated for the characterization of drinking water and consumer beverages. We describe the modular data processing and machine learning framework that can be applied by sensor researchers to accommodate different signal modalities and perform various downstream tasks, such as the verification of a product’s originality, the estimation of ion concentrations, and the quantitative prediction of sensory descriptors. Full article

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3 pages, 470 KiB

Open AccessAbstract

Modified Local Regression for Signal Resampling

by Reiner Jedermann, Yogesh Kapoor and Walter Lang

Proceedings 2024, 97(1), 68; https://doi.org/10.3390/proceedings2024097068 - 21 Mar 2024

Viewed by 347

Abstract

The resampling of sensor signals to compensate for deviating sampling intervals, clock jitter, or missing samples is still challenging. Real-time applications demand low latency and restriction of the input data window to past samples. Furthermore, most practical sensor signals are overlaid with noise. [...] Read more.

The resampling of sensor signals to compensate for deviating sampling intervals, clock jitter, or missing samples is still challenging. Real-time applications demand low latency and restriction of the input data window to past samples. Furthermore, most practical sensor signals are overlaid with noise. A new resampling method that provides a lower error than four other common interpolation methods under such conditions is introduced. Full article

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3 pages, 415 KiB

Open AccessAbstract

Morpho-Mechanical Characterization and Removal Strategy of Pile-Ups in AFM-Based Nanolithography

by Paolo Pellegrino, Isabella Farella, Lorenzo Vincenti, Mariafrancesca Cascione, Valeria De Matteis, Fabio Quaranta and Rosaria Rinaldi

Proceedings 2024, 97(1), 69; https://doi.org/10.3390/proceedings2024097069 - 21 Mar 2024

Viewed by 400

Abstract

Nowadays, mechanical AFM-based nanolithography has emerged as the most promising nanolithography technique, allowing the patterning of nanostructures on polymer layers with a sub-nanometer resolution. In such a stimulating context, we developed the Pulse-AFM method to obtain continuous structures with a controlled depth profile, [...] Read more.

Nowadays, mechanical AFM-based nanolithography has emerged as the most promising nanolithography technique, allowing the patterning of nanostructures on polymer layers with a sub-nanometer resolution. In such a stimulating context, we developed the Pulse-AFM method to obtain continuous structures with a controlled depth profile, either constant or variable, on a polymer layer. However, those nanostructures are contoured by polymer pile-ups that limit their integration into high-tech devices. Since pile-up removal is still an open challenge, AFM force–distance curve analysis was performed to characterize the stiffness of bulges, and an effective strategy to easily remove pile-ups while preserving the shape and morphology of nanostructures was then developed. Full article

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3 pages, 443 KiB

Open AccessAbstract

Non-Stationary Gas Sensors Based on WSe₂ or MoS₂ Calibrated upon NH₃ Exposure

by Filiberto Ricciardella, Kangho Lee, Niall McEvoy, Mark McCrystall and Georg S. Duesberg

Proceedings 2024, 97(1), 70; https://doi.org/10.3390/proceedings2024097070 - 21 Mar 2024

Viewed by 430

Abstract

We report on the calibration of gas sensors based on two transition metal dichalcogenides, molybdenum disulfide or tungsten diselenide, grown by the thermally assisted conversion of patterned Mo or W. The sensors showed non-stationary behavior when exposed to ammonia (NH₃) in [...] Read more.

We report on the calibration of gas sensors based on two transition metal dichalcogenides, molybdenum disulfide or tungsten diselenide, grown by the thermally assisted conversion of patterned Mo or W. The sensors showed non-stationary behavior when exposed to ammonia (NH₃) in the range of 10–100 parts per million at room temperature. This drawback hampered the calibration of the sensors. Applying the time-differential signal output (TDSO) enabled us to overcome the issue since the maxima of TDSO were uniquely and linearly correlated to the NH₃ concentration. The outcomes show that TDSO is a powerful, reliable, and valid approach when gas sensors are exposed to both oxidizing and reducing atmospheres. Full article

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3 pages, 960 KiB

Open AccessAbstract

Optically Induced Dielectrophoresis and Machine Learning Algorithms for the Identification of the Circulating Tumor Cells

by Joanna Filippi, Francesca Corsi, Paola Casti, Gianni Antonelli, Michele D’Orazio, Francesco Capradossi, Rosamaria Capuano, Giorgia Curci, Lina Ghibelli, Arianna Mencattini and Eugenio Martinelli

Proceedings 2024, 97(1), 71; https://doi.org/10.3390/proceedings2024097071 - 21 Mar 2024

Viewed by 442

Abstract

Detecting circulating tumor cells (CTCs) is a challenge in cancer research. Their dissemination into the blood stream represents a crucial event in the formation of the metastases from the primary tumor. For this reason, targeting CTCs in human liquid biopsies is a warning [...] Read more.

Detecting circulating tumor cells (CTCs) is a challenge in cancer research. Their dissemination into the blood stream represents a crucial event in the formation of the metastases from the primary tumor. For this reason, targeting CTCs in human liquid biopsies is a warning event for cancer invasiveness, progression, and prognosis. In this regard, by means of the optically induced dielectrophoresis (ODEP) technique, we investigated the response to the electric field, at different frequencies, of human prostatic carcinoma PC3 cells, which mimic CTCs derived from prostate cancer, and human leukemia monocytic THP-1 cells, which simulate circulating monocytes. The obtained spectra of the cell motion descriptors represent the unique identification signature of each cell type. Full article

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3 pages, 889 KiB

Open AccessAbstract

Low-Voltage Tri-Electrode Electrostatic Actuator Using Solid Gap-Spacing Materials

by Mehdi Allameh, Byoungyoul Park and Cyrus Shafai

Proceedings 2024, 97(1), 72; https://doi.org/10.3390/proceedings2024097072 - 21 Mar 2024

Viewed by 381

Abstract

Employing a tri-electrode electrostatic actuator revealed a significant improvement in reducing the controlling voltage. However, the primary electrode fixed voltage can be a few times higher than the conventional topology. In this work, materials with relative permittivity of ε_r = 4.2, 6.2 [...] Read more.

Employing a tri-electrode electrostatic actuator revealed a significant improvement in reducing the controlling voltage. However, the primary electrode fixed voltage can be a few times higher than the conventional topology. In this work, materials with relative permittivity of ε_r = 4.2, 6.2 and 10 were explored as the spacing material to reduce the primary voltage, and the results are compared with using air. Simulations showed that the controlling voltage can be reduced more than two times (at ε_r = 4.2) compared to the conventional topology while the primary electrode voltage required is lower than for air spacing and not more than two times larger than the conventional. Full article

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3 pages, 1299 KiB

Open AccessAbstract

MEMS Valves with Molecular Flow Regime Orifices

by Alvise Bagolini, Raffaele Correale, Antonino Picciotto and Leandro Lorenzelli

Proceedings 2024, 97(1), 73; https://doi.org/10.3390/proceedings2024097073 - 21 Mar 2024

Viewed by 443

Abstract

In this work, a novel, silicon-based micro-electromechanical valve that includes a submicrometric orifice and can operate at pressure gradients of 1 bar was used to enhance sampling for gas chromatograph mass spectrometers. The valve is based on a membrane-in-membrane design and operates with [...] Read more.

In this work, a novel, silicon-based micro-electromechanical valve that includes a submicrometric orifice and can operate at pressure gradients of 1 bar was used to enhance sampling for gas chromatograph mass spectrometers. The valve is based on a membrane-in-membrane design and operates with thermomechanical actuation. It includes a pin to enable self-cleaning. Prototypes were fabricated and preliminary testing was performed. Full article

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3 pages, 693 KiB

Open AccessAbstract

Ecoresorbable Radio-Frequency Platform for Humidity and Temperature Sensing

by James Bourely, Jaemin Kim, Xavier Aeby, Gilberto Siqueira, Gustav Nyström, Oleksandr Vorobyov, Christian Beyer, David Schmid and Danick Briand

Proceedings 2024, 97(1), 74; https://doi.org/10.3390/proceedings2024097074 - 22 Mar 2024

Viewed by 413

Abstract

Aiming to reduce electronic waste in sensing applications, we report on an eco-friendly printed microstrip line to sense relative humidity (RH) and temperature. The device is made of zinc resonators on paper used as transducers, which are coated with beeswax as an encapsulant, [...] Read more.

Aiming to reduce electronic waste in sensing applications, we report on an eco-friendly printed microstrip line to sense relative humidity (RH) and temperature. The device is made of zinc resonators on paper used as transducers, which are coated with beeswax as an encapsulant, and uses konjac as a humidity sensitive coating. The multi-resonating structure, operating in the S-band, shows reproducible temperature and humidity sensing from 15 °C to 35 °C and 30% to 70% RH with sensitivities up to 1.9 MHz/°C and 2.0 MHz/%RH, respectively. This combination of transducing and sensing materials is promising for the realization of disposable environmental sensors. Full article

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3 pages, 359 KiB

Open AccessAbstract

Colour Catcher^®: A Low-Cost Support for Developing Colorimetric Sensors for PFOA Detection

by Fabrizio Caroleo, Francesco Pizzoli, Gabriele Magna, Valerio Allegra, Sara Nardis, Corrado Di Natale, Emma Gallo and Roberto Paolesse

Proceedings 2024, 97(1), 75; https://doi.org/10.3390/proceedings2024097075 - 22 Mar 2024

Viewed by 410

Abstract

In this work, we report the development of an optical sensor based on the colour variation of a silicon corrole upon interaction with specific emerging pollutants belonging to the PFAS family in water samples. The solid support on which the receptor is deposited [...] Read more.

In this work, we report the development of an optical sensor based on the colour variation of a silicon corrole upon interaction with specific emerging pollutants belonging to the PFAS family in water samples. The solid support on which the receptor is deposited consists of Colour Catcher^® paper strips. An optical portable platform composed of low-cost electronic devices, such as an LED as a light source and a webcam as a detector, was developed to digitalize the strip colour changes during the measurements. This instrument is able to perform in situ analysis of water sources to determine the perfluoroalkyl substance (PFASs) content. Data analysis using the hue parameter allowed for the calculation, with great sensitivity, of the PFOA concentration depending on colour changes. Full article

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3 pages, 866 KiB

Open AccessAbstract

Development of an Indirect Photoacoustic Sensor Concept for Highly Accurate Low-ppm Gas Detection

by Ananya Srivastava, Achim Bittner and Alfons Dehé

Proceedings 2024, 97(1), 76; https://doi.org/10.3390/proceedings2024097076 - 22 Mar 2024

Viewed by 391

Abstract

Indirect photoacoustic sensing (PAS) offers accurate low-ppm gas measurements, with an inverse relation of the obtained signal to the measured gas concentration. The gas is sealed in transistor outline (TO) housing using a new method. This provides a relatively a very small volume [...] Read more.

Indirect photoacoustic sensing (PAS) offers accurate low-ppm gas measurements, with an inverse relation of the obtained signal to the measured gas concentration. The gas is sealed in transistor outline (TO) housing using a new method. This provides a relatively a very small volume for the reference gas signal. The gas sensing system features a black body source, highly reflective measurement volumes and TO housing sealed with gas and multiple sensors. CO₂ is used for testing and characterizing the sensor sealing and working concepts in the measurement range 0–2000 ppm, with other gases, such as CO, methane, etc., planned to be tested. A PAS signal corresponding to a 4 ppm minimum gas concentration is measured. Allan Deviation measurements provide a theoretical limit of detection of 3.14 ppm, with the integration time of 5.2 × 10³ s. Full article

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3 pages, 822 KiB

Open AccessAbstract

Optical Interference Analysis of ZIF-8 Films for Chemical Vapor Detection

by Anna Estany-Macià, Sachin Navale, Ignasi Fort-Grandas, Nirav Joshi, Albert Romano-Rodríguez and Mauricio Moreno-Sereno

Proceedings 2024, 97(1), 77; https://doi.org/10.3390/proceedings2024097077 - 22 Mar 2024

Viewed by 388

Abstract

Metal–organic frameworks (MOFs) are materials that feature a large surface area with permanent porosity, which is an attractive property for chemical and gas sensing, making them a good candidate for sensor fabrication. In this paper, we present a sensor that employs zeolitic-imidazolate-based MOFs [...] Read more.

Metal–organic frameworks (MOFs) are materials that feature a large surface area with permanent porosity, which is an attractive property for chemical and gas sensing, making them a good candidate for sensor fabrication. In this paper, we present a sensor that employs zeolitic-imidazolate-based MOFs (ZIF-8) to detect ethanol vapors via refractive index-dependent optical interference. Full article

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2 pages, 499 KiB

Open AccessAbstract

Comparative Assessment of Gold Nanoparticle–Antibody Conjugates with Two Differently Shaped Particles for Multimodal Colorimetric Lateral Flow Assay

by Vinayak Sharma, Bilal Javed and Furong Tian

Proceedings 2024, 97(1), 78; https://doi.org/10.3390/proceedings2024097078 - 21 Mar 2024

Viewed by 387

Abstract

Novel detection strategies that exploit the unique properties of gold nanoparticles (AuNPs) hold great potential for the advancement of point-of-care (POC) diagnostics, such as lateral flow and dipstick immunoassay [...] Full article

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3 pages, 513 KiB

Open AccessAbstract

Efficient Methane Monitoring with Low-Cost Chemical Sensors and Machine Learning

by Guillem Domènech-Gil, Nguyen Thanh Duc, J. Jacob Wikner, Jens Eriksson, Donatella Puglisi and David Bastviken

Proceedings 2024, 97(1), 79; https://doi.org/10.3390/proceedings2024097079 - 22 Mar 2024

Viewed by 523

Abstract

We present a method to monitor methane at atmospheric concentrations with errors in the order of tens of parts per billion. We use machine learning techniques and periodic calibrations with reference equipment to quantify methane from the readings of an electronic nose. The [...] Read more.

We present a method to monitor methane at atmospheric concentrations with errors in the order of tens of parts per billion. We use machine learning techniques and periodic calibrations with reference equipment to quantify methane from the readings of an electronic nose. The results obtained demonstrate versatile and robust solution that outputs adequate concentrations in a variety of different cases studied, including indoor and outdoor environments with emissions arising from natural or anthropogenic sources. Our strategy opens the path to a wide-spread use of low-cost sensor system networks for greenhouse gas monitoring. Full article

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3 pages, 709 KiB

Open AccessAbstract

Optical Detection System of Heavy Metals Based on Microplasma Excitation

by Tomasz Matusiak, Arkadiusz Dąbrowski and Leszek Golonka

Proceedings 2024, 97(1), 80; https://doi.org/10.3390/proceedings2024097080 - 22 Mar 2024

Viewed by 384

Abstract

This paper presents the outcome of a study on the reliability of sensors utilizing microplasma to analyze the amount of selected elements in aqueous solutions. Increasing environmental pollution poses new challenges for protective services through real-time monitoring. The aim of this work was [...] Read more.

This paper presents the outcome of a study on the reliability of sensors utilizing microplasma to analyze the amount of selected elements in aqueous solutions. Increasing environmental pollution poses new challenges for protective services through real-time monitoring. The aim of this work was to develop miniature plasma generators for the excitation and then analysis of aqueous solutions. Full article

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3 pages, 430 KiB

Open AccessAbstract

Low-Cost, Low-Footprint X-ray Sensors Based on Colloidal Quantum Dots

by Marco Ruggieri, Elisabetta Colantoni, Eleonora Marconi, Andrea Fabbri, Paolo Branchini, Andrea De Iacovo, Lorenzo Colace and Luca Tortora

Proceedings 2024, 97(1), 81; https://doi.org/10.3390/proceedings2024097081 - 22 Mar 2024

Viewed by 339

Abstract

Development of novel and inexpensive X-ray detectors is of key importance for numerous applications, such as dosimetry in nuclear and medical facilities, diagnostics in cultural heritage, and homeland security. Solution-processed materials are being investigated as novel x-ray sensing materials, with constant improvements that [...] Read more.

Development of novel and inexpensive X-ray detectors is of key importance for numerous applications, such as dosimetry in nuclear and medical facilities, diagnostics in cultural heritage, and homeland security. Solution-processed materials are being investigated as novel x-ray sensing materials, with constant improvements that are rapidly approaching commercial standards. Here, we demonstrate a detector based on PbS colloidal quantum dots (QD) fabricated in air with simple drop-casting techniques on a Si substrate with pre-patterned Au interdigitated electrodes. The device showed good linearity in the tested dose range and a maximum sensitivity value of 2370 µC Gy⁻¹ cm⁻¹, which is higher than typically reported values for commercial a-Se and poly-CZT detectors. Full article

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3 pages, 570 KiB

Open AccessAbstract

Gas Sensing Capabilities of CuInS₂/ZnO Core–Shell Quantum Dot

by Antonio Orlando, Guglielmo Trentini, Pietro Tosato, Soufiane Krik, Matteo Valt, Andrea Gaiardo and Luisa Petti

Proceedings 2024, 97(1), 82; https://doi.org/10.3390/proceedings2024097082 - 22 Mar 2024

Viewed by 439

Abstract

Chemoresistive gas sensors are surely one of the easiest and most commonly used methods to monitor the presence of different polluting gases. Nevertheless, there are still several challenges to overcome in order for these sensors to be widely used. In particular, the selectivity [...] Read more.

Chemoresistive gas sensors are surely one of the easiest and most commonly used methods to monitor the presence of different polluting gases. Nevertheless, there are still several challenges to overcome in order for these sensors to be widely used. In particular, the selectivity and sensitivity of chemoresistive gas sensors towards a wide range of analytes need to be improved. This is why new sensing materials capable of detecting different analytes in a sensitive and selective manner are being investigated. In this regard, this work is focused on the development and characterization of a new sensing material based on the quantum dot (QD) core–shell of CuInS₂/ZnO (CIS-ZO). Optimized films of the QD core–shell of CIS-ZO were integrated into a micro-electromechanical system (MEMS)-based gas sensor platform, showing excellent sensing performance versus different gases and especially towards ethanol (C₂H₅OH). Full article

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3 pages, 567 KiB

Open AccessAbstract

Integration of Printed PVDF-Based Force Sensors into a Printed Circuit Board Stack

by Sebastian Lang, Wolfgang Hilber, Herbert Enser and Bernhard Jakoby

Proceedings 2024, 97(1), 84; https://doi.org/10.3390/proceedings2024097084 - 22 Mar 2024

Viewed by 343

Abstract

This work reports on the fabrication and testing of force sensors integrated directly into a printed circuit board (PCB). For this purpose, a layer of poly(vinylidene fluoride-trifluoroethylen) (P(VDF-TrFE)) is printed onto two pieces of two two-layer PCBs, which are then stacked together to [...] Read more.

This work reports on the fabrication and testing of force sensors integrated directly into a printed circuit board (PCB). For this purpose, a layer of poly(vinylidene fluoride-trifluoroethylen) (P(VDF-TrFE)) is printed onto two pieces of two two-layer PCBs, which are then stacked together to create a four-layer PCB. The devised and fabricated sensor with the described measurement setup features a nearly linear measurement characteristic in the range between 0.3 and 1.2 N and a detection limit of approximately 10 mN. Full article

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3 pages, 1014 KiB

Open AccessAbstract

Comparison of Bacterial Cellulose Deformation Sensors Based on Choline Malonate and EMIM-BF₄ Ionic Liquids

by Santhosh Kurukunda, Salvatore Cerruto, Salvatore Graziani, Carlo Trigona, Giovanna Di Pasquale, Antonino Pollicino, Kaija Põhako-Esko and Alvo Aabloo

Proceedings 2024, 97(1), 85; https://doi.org/10.3390/proceedings2024097085 - 25 Mar 2024

Viewed by 346

Abstract

Sensors and transducers are essential components of measurement systems. The achievement of a sustainable economy requires environmentally friendly solutions and processes in order to develop sensors and transducers that are capable of being recycled, disposed, and, degraded without releasing pollutants into the environment. [...] Read more.

Sensors and transducers are essential components of measurement systems. The achievement of a sustainable economy requires environmentally friendly solutions and processes in order to develop sensors and transducers that are capable of being recycled, disposed, and, degraded without releasing pollutants into the environment. In this context, we propose a comparative analysis of deformation sensors based on bacterial cellulose impregnated with choline malonate and EMIM-BF₄ ionic liquids (ILs). Their features and performance will be compared while also considering the green aspect of the proposed sensors. Full article

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3 pages, 915 KiB

Open AccessAbstract

Energy-Autonomous Tread Wear Wireless Sensor System for Tire Monitoring

by Robert A. Lockhart, Pattanaphong Janphuang, Francisco Molina-Lopez, Andres Vasquez Quintero, Gabriele Tasselli, Patrick Favre, Cyril Botteron, Pierre-André Farine and Danick Briand

Proceedings 2024, 97(1), 86; https://doi.org/10.3390/proceedings2024097086 - 25 Mar 2024

Viewed by 372

Abstract

Technologies are going through a digitalization process. Convergence of 2D printing with 3D printing is leading to 3D structural electronics. Implementation during their fabrication of sensing components in objects using printing would make these 3D-printed objects smarter. At the same time, sensors production [...] Read more.

Technologies are going through a digitalization process. Convergence of 2D printing with 3D printing is leading to 3D structural electronics. Implementation during their fabrication of sensing components in objects using printing would make these 3D-printed objects smarter. At the same time, sensors production would benefit, thanks to their digital manufacturing in the 3rd dimension, from customization, self-packaging, and better integration into products. We are proposing to apply digital printing of functional and structural inks addressing the challenges of the whole processing in a single tool. Developments in the field of smart wearables are presented. Full article

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3 pages, 454 KiB

Open AccessAbstract

Machine Learning for Enhanced Operation of Underperforming Sensors in Humid Conditions

by Guillem Domènech-Gil and Donatella Puglisi

Proceedings 2024, 97(1), 87; https://doi.org/10.3390/proceedings2024097087 - 25 Mar 2024

Viewed by 354

Abstract

Using a single sensor as a virtual electronic nose, we demonstrate the possibility of obtaining good results with underperforming sensors that, at first glance, would be discarded. For this aim, we characterized chemical gas sensors with low repeatability and random drift towards both [...] Read more.

Using a single sensor as a virtual electronic nose, we demonstrate the possibility of obtaining good results with underperforming sensors that, at first glance, would be discarded. For this aim, we characterized chemical gas sensors with low repeatability and random drift towards both dangerous and innocuous volatile organic compounds (VOCs) under different levels of relative humidity. Our results show classification accuracies higher than 90% when differentiating harmful from harmless VOCs and coefficients of determination, R², higher than 80% when determining their concentration in the parts per billion to parts per million range. Full article

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3 pages, 333 KiB

Open AccessAbstract

Investigation on the Development, Stabilization and Impact of Thermally Induced Oxygen Vacancies on the Chemoresistive Sensing Properties of MOX

by Andrea Gaiardo, Lia Vanzetti, Andrea Pedrielli, Matteo Valt and Soufiane Krik

Proceedings 2024, 97(1), 88; https://doi.org/10.3390/proceedings2024097088 - 25 Mar 2024

Viewed by 334

Abstract

Gas sensors based on metal oxide (MOX) semiconductors doped with oxygen vacancies (VO) have many advantages over stoichiometric MOX, such as higher surface reactivity and lower operating temperature. However, preparing reduced MOX is challenging, and the impact of different VO types and concentration [...] Read more.

Gas sensors based on metal oxide (MOX) semiconductors doped with oxygen vacancies (VO) have many advantages over stoichiometric MOX, such as higher surface reactivity and lower operating temperature. However, preparing reduced MOX is challenging, and the impact of different VO types and concentration on sensing performance is still unclear. In this work, we developed a tailored reducing thermal treatment for creating controlled VO in MOX. The effect of the length and temperature of the treatment was investigated using several characterization methods. Finally, measurements were performed to evaluate the impact of VO type and concentration on reduced MOX sensing performance. Full article

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3 pages, 2415 KiB

Open AccessAbstract

Engineered Porous Metal Structures via Electroplating in Two-Photon Polymerized Molds

by Ana Luiza Silveira Fiates, Sina Reede, Franziska Bollhorst, Lukas Hansen, Klaus Froehner and Michael J. Vellekoop

Proceedings 2024, 97(1), 89; https://doi.org/10.3390/proceedings2024097089 - 25 Mar 2024

Viewed by 325

Abstract

We report the realization of metallic 3D microstructures, electroplated in two-photon polymerized molds. These molds are typically 150 × 150 × 30 µm³ in size and the smallest feature size is about 1 µm. After the electroplating process, the mold is removed [...] Read more.

We report the realization of metallic 3D microstructures, electroplated in two-photon polymerized molds. These molds are typically 150 × 150 × 30 µm³ in size and the smallest feature size is about 1 µm. After the electroplating process, the mold is removed by means of CF₄/O₂ etching (1 h). The vertical electroplating growth is about two times higher than the horizontal growth, which creates voids. A new design to prevent voids was tested where the pores were arranged at a 35° angle to the chip surface. The remaining structures consisted of a copper base with a palladium finish, or of pure palladium. They were analyzed through SEM and were shown to be a good reproduction of the mold design, resulting in metallic porous structures with a specific surface area of about 6 mm²/mm². Full article

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3 pages, 348 KiB

Open AccessAbstract

Influence of Ultrasonic Bath on Mold-Assisted Electrodeposition of Gold Microelectrode Arrays

by Neeraj Yadav, Flavio Giacomozzi, Alessandro Cian, Damiano Giubertoni and Leandro Lorenzelli

Proceedings 2024, 97(1), 90; https://doi.org/10.3390/proceedings2024097090 - 25 Mar 2024

Viewed by 361

Abstract

This study investigates the potential of ultrasonic baths to enhance mold-assisted electrodeposition for fabricating three-dimensional (3D) microelectrode arrays (MEAs) with improved quality and reliability. Focusing on gold microstructures, commonly employed in 3D MEAs due to their biocompatibility and electrical conductivity, we explore how [...] Read more.

This study investigates the potential of ultrasonic baths to enhance mold-assisted electrodeposition for fabricating three-dimensional (3D) microelectrode arrays (MEAs) with improved quality and reliability. Focusing on gold microstructures, commonly employed in 3D MEAs due to their biocompatibility and electrical conductivity, we explore how ultrasonic vibrations impact the electrodeposition process. Through the formation of microscopic bubbles and reactive sites, ultrasonic baths accelerate deposition, offering potential benefits such as increased deposition rates, uniformity, and cost-effectiveness. Our experimental findings demonstrate significant improvements in deposition rate and uniformity, highlighting the potential of ultrasonic baths to advance the fabrication of 3D MEAs for various biomedical applications. Full article

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3 pages, 355 KiB

Open AccessAbstract

From Gas Sensors to Artificial Neural Networks: A New Precision Farming Approach for Crop Coefficient Determination

by Francesco Tralli, Barbara Fabbri, Matteo Valt, Alessandro Drago and Vincenzo Guidi

Proceedings 2024, 97(1), 91; https://doi.org/10.3390/proceedings2024097091 - 25 Mar 2024

Viewed by 341

Abstract

This study aims to utilize gaseous emissions from cultivation to predict the crop coefficient, an indirect measure of plant water stress. An array of chemiresistive gas sensors was used to collect the data, which were then processed by a simple artificial neural network [...] Read more.

This study aims to utilize gaseous emissions from cultivation to predict the crop coefficient, an indirect measure of plant water stress. An array of chemiresistive gas sensors was used to collect the data, which were then processed by a simple artificial neural network algorithm. The results highlighted that the gas emissions from tomato crops can be used as a reliable indicator for determining the crop coefficient, allowing for more efficient and effective irrigation management. This research offers a potential solution to the growing issue of water scarcity in agriculture by providing a cost-effective and practical method for monitoring crop water status. Full article

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3 pages, 501 KiB

Open AccessAbstract

From a Memory Sensor to a Sensor without Memory: Trigger Mechanism

by Giada Marchi, Viviana Mulloni, Andrea Gaiardo, Matteo Valt, Massimo Donelli and Leandro Lorenzelli

Proceedings 2024, 97(1), 92; https://doi.org/10.3390/proceedings2024097092 - 25 Mar 2024

Viewed by 347

Abstract

In the context of environmental monitoring, maximum levels of nitrogen dioxide (NO₂) are internationally regulated since long exposure impacts health. In general, very low concentrations in the sub-ppm range are found for NO₂, which implies the need for very [...] Read more.

In the context of environmental monitoring, maximum levels of nitrogen dioxide (NO₂) are internationally regulated since long exposure impacts health. In general, very low concentrations in the sub-ppm range are found for NO₂, which implies the need for very sensitive detection systems. Here, we demonstrate a chipless RFID sensing cell with both threshold detection and re-usability capabilities. Full article

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3 pages, 476 KiB

Open AccessAbstract

Humidity Impact on Thermal Conductivity Sensors

by Sophie Emperhoff, Matthias Eberl, Tim Dwertmann and Jürgen Wöllenstein

Proceedings 2024, 97(1), 93; https://doi.org/10.3390/proceedings2024097093 - 25 Mar 2024

Cited by 1 | Viewed by 372

Abstract

The thermal conductivity of humid air at different saturation levels has been investigated at 70 °C. A MEMS-based thermal conductivity sensor was calibrated and used to measure the thermal conductivity of humid air. The obtained results were compared to different equations for calculating [...] Read more.

The thermal conductivity of humid air at different saturation levels has been investigated at 70 °C. A MEMS-based thermal conductivity sensor was calibrated and used to measure the thermal conductivity of humid air. The obtained results were compared to different equations for calculating the thermal conductivity of gas mixtures, in this case, dry air and water vapor. The selected equations predict contradicting behaviors of humid air at different temperatures and saturation levels. A semi-empirical equation by Melling et al. for the temperature range of 100 °C to 200 °C has shown the best agreement with the experimental data. We intend to study the temperature range from 0 to 100 °C in more detail and plan to adapt the interpolation to fit this temperature range. Full article

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3 pages, 1347 KiB

Open AccessAbstract

Multi-Micro-Sensor Platform for Monitoring Toxic Algal Blooms and Pollution in Coastal Marine Waters: Transducer Integration in Micro-Technology

by Pierre Groc, Guy Cathébras, Vincent Kerzerho, Adrian Laborde, Fabien Soulier, Pierre Temple-Boyer, Jérôme Launay and Serge Bernard

Proceedings 2024, 97(1), 94; https://doi.org/10.3390/proceedings2024097094 - 25 Mar 2024

Viewed by 344

Abstract

This work presents the design of a multisensor platform for the in situ monitoring of physico-chemical parameters in seawater. As a result, we propose an 8.5 × 8.5 mm² silicon chip that integrates a MOSFET and two ISFETs (Metal Oxide Semiconductor and [...] Read more.

This work presents the design of a multisensor platform for the in situ monitoring of physico-chemical parameters in seawater. As a result, we propose an 8.5 × 8.5 mm² silicon chip that integrates a MOSFET and two ISFETs (Metal Oxide Semiconductor and Ion-Sensitive Field-Effect Transistor) and four microelectrodes (two Ag electrodes and two Pt electrodes). The device allows measurements to be taken in liquid phase of temperature, pH, nitrate concentrations and conductivity. These silicon transducers could be integrated with conditioning electronics to achieve an autonomous environmental sensor device. Full article

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3 pages, 757 KiB

Open AccessAbstract

Inductive Sensor with Contactless Interrogation for Conductive Target Detection

by Marco Zini, Marco Baù, Alessandro Nastro, Marco Ferrari and Vittorio Ferrari

Proceedings 2024, 97(1), 95; https://doi.org/10.3390/proceedings2024097095 - 25 Mar 2024

Viewed by 315

Abstract

The contactless interrogation of an inductive sensor (IS) for conductive target detection is presented. The IS comprises a solenoidal coil of copper wire wrapped around a plastic pipe which is connected to a series capacitor to form an LC circuit resonating at the [...] Read more.

The contactless interrogation of an inductive sensor (IS) for conductive target detection is presented. The IS comprises a solenoidal coil of copper wire wrapped around a plastic pipe which is connected to a series capacitor to form an LC circuit resonating at the frequency f_r. A conductive target placed at different positions inside the pipe modifies the inductance of the coil, and in turn, f_r. An external interrogation coil (IC) electromagnetically coupled to the IS allows the f_r to be read through a contactless interrogation technique. The approach has been tested by varying both the position of a lead sphere adopted as the target and the interrogation distance d between the IS and IC. Without the sphere, the LC circuit has f_r0 = 2.51 MHz. The target sphere has been detected at up to |x| = 7.5 mm from the center of the IS coil with a frequency variation ∆ f_r = 180 kHz at x = 0. Full article

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3 pages, 651 KiB

Open AccessAbstract

Housing Molecularly Imprinted Polymer Nanoparticles in Polyvinylpyrrolidone/Multiwall Carbon Nanotube Nanofibers to Detect Chiral Terpene Vapors

by Fabricio N. Molinari, Fabrizio De Cesare and Antonella Macagnano

Proceedings 2024, 97(1), 96; https://doi.org/10.3390/proceedings2024097096 - 26 Mar 2024

Viewed by 402

Abstract

This study proposes a two-step process to design a chiral sensor combining MIP (molecularly imprinted polymer) and electrospinning technologies. First, stereoselective S(-)-limonene molecularly imprinted polymer nanoparticles (MINPs) were fabricated and dispersed into polyvinylpyrrolidone–carbon nanotube (PVP-MWCNT) conductive nanofibers to cover resistive interdigitated electrodes (IDEs). [...] Read more.

This study proposes a two-step process to design a chiral sensor combining MIP (molecularly imprinted polymer) and electrospinning technologies. First, stereoselective S(-)-limonene molecularly imprinted polymer nanoparticles (MINPs) were fabricated and dispersed into polyvinylpyrrolidone–carbon nanotube (PVP-MWCNT) conductive nanofibers to cover resistive interdigitated electrodes (IDEs). The electrical and sensing performances of the resulting sensor confirmed its capacity to discriminate and quantify the two limonene enantiomers. The sensor’s response to terpene gases appeared completely reversible, probably due to the peculiarity of the nanostructure. The sensor characteristics were influenced by the polymer matrix’s composition ratio, the cavity shape and the interfaces with carbon nanotubes. The morphological properties of the nanofibers were investigated by microscopy (optical, SEM, TEM and AFM). Full article

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3 pages, 732 KiB

Open AccessAbstract

Low-Cost Sensors Based on Nanoparticles of Tin Dioxide Decorated with Graphene Used to Detect Ultra-Low NO₂ Concentrations at Room Temperature

by Isabel Sayago, Carlos Sánchez-Vicente and José Pedro Santos

Proceedings 2024, 97(1), 97; https://doi.org/10.3390/proceedings2024097097 - 25 Mar 2024

Viewed by 320

Abstract

Chemical nanosensors based on nanoparticles (NPs) of pure tin dioxide (SnO₂) and graphene-decorated tin dioxide were developed and characterized for the detection of pollutant gases. Sensitive layers were prepared by a drop casting method. The photoactivation of the sensors allows for [...] Read more.

Chemical nanosensors based on nanoparticles (NPs) of pure tin dioxide (SnO₂) and graphene-decorated tin dioxide were developed and characterized for the detection of pollutant gases. Sensitive layers were prepared by a drop casting method. The photoactivation of the sensors allows for the detection of ultra-low NO₂ concentrations (50 ppb) at room temperature. The sensors show strong responses to NO₂ and weak ones to the other tested polluting gases (CO, CH₄ and CO₂). The effect of humidity and the presence of graphene on the sensors’ response were studied. Full article

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3 pages, 794 KiB

Open AccessAbstract

New SiC Microwire-Based Ion Sensitive Junction Field Effect Transistors (SiC ISJFETs) for pH Sensing

by Olfa Karker, Konstantinos Zekentes, Nicolaos Makris, Edwige Bano and Valérie Stambouli

Proceedings 2024, 97(1), 98; https://doi.org/10.3390/proceedings2024097098 - 26 Mar 2024

Viewed by 334

Abstract

For the first time, we have implemented new kinds of ISFETs based on silicon carbide (SiC). Thanks to its chemical inertness, SiC is an interesting semiconductor for the development of chemically robust and biocompatible ISFETs. The challenge is to replace Si NWFETs for [...] Read more.

For the first time, we have implemented new kinds of ISFETs based on silicon carbide (SiC). Thanks to its chemical inertness, SiC is an interesting semiconductor for the development of chemically robust and biocompatible ISFETs. The challenge is to replace Si NWFETs for biochemical sensing due to the lack of long-term stability of Si NWs in aqueous solutions. More particularly, we fabricated a micro/nanowire SiC-based ion-sensitive junction field-effect transistor (SiC-ISJFET) and studied its sensitivity to pH variations. The obtained sensitivity reaches 500 mV/pH, making it the first SiC pH sensor with performance equaling that of the latest NWFET Si-based pH sensors. Full article

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3 pages, 489 KiB

Open AccessAbstract

FOCV-MPPT Power Management Unit for Submilliwatt Indoor PV Cells

by Marc Azlor, Eduard Ferré, Manel Gasulla and Ferran Reverter

Proceedings 2024, 97(1), 99; https://doi.org/10.3390/proceedings2024097099 - 26 Mar 2024

Viewed by 367

Abstract

This work proposes and experimentally characterizes a low-power circuit to track the maximum power point (MPP) of submilliwatt photovoltaic (PV) cells intended for indoor applications. The circuit relies on a low-power conventional indirect tracking technique: the fractional open circuit voltage (FOCV). The experimental [...] Read more.

This work proposes and experimentally characterizes a low-power circuit to track the maximum power point (MPP) of submilliwatt photovoltaic (PV) cells intended for indoor applications. The circuit relies on a low-power conventional indirect tracking technique: the fractional open circuit voltage (FOCV). The experimental results presented herein show that power losses due to the tracking inaccuracy of the FOCV technique are much lower (at least a factor of 10) than those due to the ensuing micropower DC/DC converter. Accordingly, the application of more accurate yet more power-demanding tracking techniques seems unnecessary in such scenarios, since they could incur even higher power losses. Full article

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3 pages, 385 KiB

Open AccessAbstract

Magnetic Field Sensors for Non-Invasive Current Monitoring in Wire-Bond-Less Power Modules

by Perla Malagò, Stefano Lumetti, Dominik Holzmann, Michael Ortner and Ali Roshanghias

Proceedings 2024, 97(1), 100; https://doi.org/10.3390/proceedings2024097100 - 27 Mar 2024

Viewed by 349

Abstract

A non-invasive implementation of a planar magnetoresistive sensor on top of copper interconnected power modules is proposed. This solution allows for the real-time monitoring of the electrical current flowing across the power modules. Anisotropic magnetoresistive (AMR) sensors made of Permalloy were designed through [...] Read more.

A non-invasive implementation of a planar magnetoresistive sensor on top of copper interconnected power modules is proposed. This solution allows for the real-time monitoring of the electrical current flowing across the power modules. Anisotropic magnetoresistive (AMR) sensors made of Permalloy were designed through finite-difference and finite-element simulations in the so-called barber-pole configuration and microfabricated via patterning by laser lithography and thin film deposition by electron-beam evaporation. Finally, the sensor performance was tested by measuring the magnetic field generated by the electrical current in a specific range of interest. Full article

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3 pages, 1156 KiB

Open AccessAbstract

Electrostatic Microelectromechanical System Speaker Array with Out-of-Plane Piston Displacement and Simplified Microfabrication

by Diogo E. Aguiam, Inês S. Garcia, Edoardo Sotgiu and Filipe S. Alves

Proceedings 2024, 97(1), 101; https://doi.org/10.3390/proceedings2024097101 - 27 Mar 2024

Viewed by 368

Abstract

This study presents a new design for a MEMS electrostatic speaker array with out-of-plane piston-like diaphragm displacement using a simplified silicon-on-insulator microfabrication process. The device comprises an array of parallel actuating membranes with small circular mechanically open but acoustically sealed apertures that enable [...] Read more.

This study presents a new design for a MEMS electrostatic speaker array with out-of-plane piston-like diaphragm displacement using a simplified silicon-on-insulator microfabrication process. The device comprises an array of parallel actuating membranes with small circular mechanically open but acoustically sealed apertures that enable controlled etching of the buried oxide to be released directly from the front side, but retain a high acoustic impedance acting as a flat membrane. This approach simplifies the microfabrication process, requiring only two lithography masks and increasing process tolerances. Preliminary experimental measurements validate the concept and demonstrate the electromechanical and acoustic performance compared with theoretical models. Full article

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3 pages, 1196 KiB

Open AccessAbstract

A Novel Sensor Effect Applicable in Seismically Active Regions

by Siya Lozanova, Martin Ralchev, Avgust Ivanov and Chavdar Roumenin

Proceedings 2024, 97(1), 102; https://doi.org/10.3390/proceedings2024097102 - 27 Mar 2024

Viewed by 316

Abstract

This paper reports a novel sensor effect in solid non-regular materials with the following formula: a previously unknown phenomenon in solid disordered structures, such as rocks and building concrete, has been experimentally established, which is expressed in the emission of micro-sized particles under [...] Read more.

This paper reports a novel sensor effect in solid non-regular materials with the following formula: a previously unknown phenomenon in solid disordered structures, such as rocks and building concrete, has been experimentally established, which is expressed in the emission of micro-sized particles under the action of uniaxial pressures. The obtained results are an integrated technology indicator for pre-emergency and emergency conditions in mountain massifs and are applicable in seismically active regions. Full article

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3 pages, 860 KiB

Open AccessAbstract

Multi-Sensor System for Saffron Quality Identification

by Rosamaria Capuano, Chiara Serafini, Leonardo Papale, Valerio Allegra, Corrado Di Natale and Alexandro Catini

Proceedings 2024, 97(1), 103; https://doi.org/10.3390/proceedings2024097103 - 27 Mar 2024

Viewed by 335

Abstract

The high commercial value of saffron prompts attempts to adulterate this commodity. Thus, there is growing interest in fast and simple methods of identifying quality products. Color and aroma are the most appreciated characteristics of saffron that make this spice widely used. On [...] Read more.

The high commercial value of saffron prompts attempts to adulterate this commodity. Thus, there is growing interest in fast and simple methods of identifying quality products. Color and aroma are the most appreciated characteristics of saffron that make this spice widely used. On these bases, we developed a multisensor approach to saffron quality identification based on VIS spectrometry and volatile compound detection. For scopes, a miniaturized spectrophotometer and an electronic nose were used to identify high-quality saffron with respect to less-valuable commercial products and adulterant agents. The outer product of the spectra and electronic nose patterns was demonstrated to be effective at clustering samples according to their purity. Full article

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2 pages, 128 KiB

Open AccessAbstract

Construction of an Array of Antibody–Gold Nanoparticle Conjugates for Their Comparative Assessment on Multiplex Lateral Flow Test to Detect Mycotoxins

by Bilal Javed, Vinayak Sharma and Furong Tian

Proceedings 2024, 97(1), 104; https://doi.org/10.3390/proceedings2024097104 - 27 Mar 2024

Viewed by 374

Abstract

A multiplex lateral flow immuno-biosensor for rapid, simple, and ultrasensitive on-site quantification of aflatoxin B1, type B-Fumonisin, and zearalenone in food requires the conjugation of their anti-toxin antibodies to the gold nanoparticles of various colors and sizes to obtain different color test lines [...] Read more.

A multiplex lateral flow immuno-biosensor for rapid, simple, and ultrasensitive on-site quantification of aflatoxin B1, type B-Fumonisin, and zearalenone in food requires the conjugation of their anti-toxin antibodies to the gold nanoparticles of various colors and sizes to obtain different color test lines [...] Full article

3 pages, 647 KiB

Open AccessAbstract

Microengineered Flexible Pressure Sensors with Sacrificial Molding Layer: A Novel Fabrication Approach for Improved Performance

by Maria Brites Atalaia Rosa and Michael Kraft

Proceedings 2024, 97(1), 105; https://doi.org/10.3390/proceedings2024097105 - 27 Mar 2024

Viewed by 358

Abstract

Recent research aims to improve the performance of flexible pressure sensors by microengineering their active layer. However, current fabrication approaches often require a trade-off between scalability, miniaturization, and performance. To overcome these limitations, we propose a novel technique that involves stacking all sensor [...] Read more.

Recent research aims to improve the performance of flexible pressure sensors by microengineering their active layer. However, current fabrication approaches often require a trade-off between scalability, miniaturization, and performance. To overcome these limitations, we propose a novel technique that involves stacking all sensor layers on a carrier wafer and shaping the active layer into micro-cones using a sacrificial mold. Precise miniaturization through photolithography techniques improves mapping resolution, useful for object recognition applications. This method offers enhanced ease of fabrication, versatility in shape and size, and tunability, potentially improving the efficacy of flexible pressure sensors for various applications. Full article

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3 pages, 183 KiB

Open AccessAbstract

An Innovative Layer on Surface Acoustic Wave Sensors Integrated in a Cascade Impactor to Optimize PM10 Detection for Air Pollution Monitoring

by Ghida Fawaz, Meddy Vanotti, Fatima-Ezzahraa Dbibih, Valérie Soumann, Sacha Poisson and Virginie Blondeau-Patissier

Proceedings 2024, 97(1), 106; https://doi.org/10.3390/proceedings2024097106 - 27 Mar 2024

Viewed by 345

Abstract

A cascade impactor coupled with Surface Acoustic Wave (SAW) sensors was developed in our laboratory to detect Particulate Matters with an aerodynamic diameter of less or equal to 2.5 and 10 µm (PM2.5 and PM10). To improve the collection of PM10, a layer [...] Read more.

A cascade impactor coupled with Surface Acoustic Wave (SAW) sensors was developed in our laboratory to detect Particulate Matters with an aerodynamic diameter of less or equal to 2.5 and 10 µm (PM2.5 and PM10). To improve the collection of PM10, a layer was added to the SAW sensors, which was later on tested to check its effectiveness. These tests were carried out using polystyrene (PS) and silicon carbide (SiC) particles in order to have a representative sample of sizes. Results analysis was conducted quantitatively using a digital microscope. Full article

3 pages, 406 KiB

Open AccessAbstract

Optimization of Dielectric Excitation for Metal Oxide Sensors: Simulation and Experimental Results

by Alessandro Benegiamo, Meryl Cruz, Stefano Robbiani, Raffaele Dellacá and Santiago Marco

Proceedings 2024, 97(1), 107; https://doi.org/10.3390/proceedings2024097107 - 27 Mar 2024

Viewed by 353

Abstract

This study assesses the agreement in terms of linearity errors between simulated and experimental data from MOX sensors operated in dielectric excitation mode. Both simulated and experimental reactance spectra exhibit high linearity with respect to gas concentration in the high-frequency shoulder of the [...] Read more.

This study assesses the agreement in terms of linearity errors between simulated and experimental data from MOX sensors operated in dielectric excitation mode. Both simulated and experimental reactance spectra exhibit high linearity with respect to gas concentration in the high-frequency shoulder of the relaxation peak. The results demonstrate strong agreement between simulated and experimental 95% CI of absolute linearity errors as a function of frequency. As expected, the empirical errors are slightly bigger compared to the simulation prediction, since the latter only considers the linearity errors. The good correspondence between simulations and empirical results supports the use of simulation to optimize the tuning capacitor and the selection of the optimal operating frequency. Full article

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3 pages, 673 KiB

Open AccessAbstract

Measuring Exhaled Propofol in an Ex Vivo Lung Model with Low-Cost Metal Oxide Gas Sensors

by Christian Bur, Ksenia Karst, Andreas Schütze, Felix Maurer, Stefan Radermacher, Klaus Hoffmann and Sascha Kreuer

Proceedings 2024, 97(1), 108; https://doi.org/10.3390/proceedings2024097108 - 27 Mar 2024

Viewed by 343

Abstract

Herein, commercially available MOS gas sensors running in temperature cycling operations are studied for the online monitoring of propofol in an ex vivo ventilation and perfusion lung model. A porcine lung was connected to a heart–lung machine and propofol was added into the [...] Read more.

Herein, commercially available MOS gas sensors running in temperature cycling operations are studied for the online monitoring of propofol in an ex vivo ventilation and perfusion lung model. A porcine lung was connected to a heart–lung machine and propofol was added into the blood reservoir. The MOS sensor was able to quantitatively detect exhaled propofol in the very low ppb range. The results are in accordance with those obtained by a propofol-sensitive ion mobility spectrometer. Full article

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2 pages, 568 KiB

Open AccessAbstract

Optimization of a Drone-Based System for Instrumental Odor Monitoring Using Feature Selection

by Alessandro Benegiamo, Javier Burgués, Javier Alonso-Valdesueiro, Beatrice Julia Lotesoriere, Lara Terrén, Lidia Sauco, Mª Deseada Esclapez, Silvia Doñate, Agustín Gutiérrez-Gálvez and Santiago Marco

Proceedings 2024, 97(1), 109; https://doi.org/10.3390/proceedings2024097109 - 27 Mar 2024

Viewed by 314

Abstract

The application of Instrumental Odor Monitoring Systems (IOMS) for odor concentration estimation in wastewater treatment plants remains a challenge. We present the optimization of a heterogeneous gas sensor array mounted on a small drone to be used in dynamic conditions. The proposed method [...] Read more.

The application of Instrumental Odor Monitoring Systems (IOMS) for odor concentration estimation in wastewater treatment plants remains a challenge. We present the optimization of a heterogeneous gas sensor array mounted on a small drone to be used in dynamic conditions. The proposed method is based on the use of feature selection during the estimation of the best calibration model. The results show that the selection of an optimal sensor array and the proper time window decreases the multiplicative error a 25%. Full article

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3 pages, 3976 KiB

Open AccessAbstract

Development of Fluid Handling Capabilities for Autonomous Sampling Capsule

by Bharathesh Badadamath, Desmond Brennan, Paul D. Cotter and Paul Galvin

Proceedings 2024, 97(1), 110; https://doi.org/10.3390/proceedings2024097110 - 21 Mar 2024

Viewed by 260

Abstract

This work focusses on the design of a swallowable smart capsule to collect rumen samples from a cow’s rumen and small intestine. The capsule (60 mm long × 25 mm diameter) passively travels along the cow’s GI tract, identifies the region of interest, [...] Read more.

This work focusses on the design of a swallowable smart capsule to collect rumen samples from a cow’s rumen and small intestine. The capsule (60 mm long × 25 mm diameter) passively travels along the cow’s GI tract, identifies the region of interest, collects a sample, and chemically stabilizes it for offline omics analysis. Key components in the fluidic system include (i) a micro pump, (ii) valves, and (iii) a fluidic reservoir. As a preliminary design step, we investigated sample collection and reagent mixing protocols on a bench-top fluidic system. A model rumen sample (80% glycerol/water) of similar viscosity to rumen fluid was used in our research to evaluate pumping and mixing with a stabilizing reagent. Full article

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3 pages, 1362 KiB

Open AccessAbstract

Development of a Potentiometric Nitrate Ion Microsensor Improved Using Conductive Polymer Doped with Carbon Nanotubes as a Transducing Layer

by Camille Bene, Emmanuel Flahaut, Morgan Legnani, Pierre Temple-Boyer and Jérôme Launay

Proceedings 2024, 97(1), 111; https://doi.org/10.3390/proceedings2024097111 - 27 Mar 2024

Viewed by 330

Abstract

An all-integrated on-chip electrochemical microcell (10 × 11 mm²) is developed using silicon technology. The potentiometric nitrate ion detection is based on the functionalization of the working microelectrode array with a polymer membrane in fluoropolysiloxane (FPSX) containing ionophore tetradodecylammoniumnitrate (TDDAN) and [...] Read more.

An all-integrated on-chip electrochemical microcell (10 × 11 mm²) is developed using silicon technology. The potentiometric nitrate ion detection is based on the functionalization of the working microelectrode array with a polymer membrane in fluoropolysiloxane (FPSX) containing ionophore tetradodecylammoniumnitrate (TDDAN) and ionic additive potassium tetrakis[3,5-bis(trifuoromethyl)phenyl]borate (KTFPB) to form an all-solid-state ion selective electrode (ISE). The addition of an ion-to-electron transducing layer between the platinum working electrode and the polymer membrane helped to improve the sensor performances, especially the response time, the sensitivity, and the stability. Composites formed with two conductive polymers were compared: Polyethylenedioxythiophène (PEDOT) and Polypyrrole (PPy), doped with Poly(styrene sulfonate) or double-walled carbon nanotubes (DWCNTs). Full article

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3 pages, 785 KiB

Open AccessAbstract

Optical System Design and Characterization of MEMS Mirror-Based SPAD LiDAR System for Smart Factory Applications

by Jeong-Yeon Hwang, Paul Raschdorf, Andre Henschke, Manuel Ligges, Sara Weyer and Shanshan Gu-Stoppel

Proceedings 2024, 97(1), 112; https://doi.org/10.3390/proceedings2024097112 - 28 Mar 2024

Viewed by 411

Abstract

This paper presents the optical system design for the MEMS mirror-based SPAD LiDAR system. The transmitter of the proposed LiDAR system consists of related optics for incident beam expansion and a piezoelectric MEMS mirror for a wide-scanning field of view. For the receiver [...] Read more.

This paper presents the optical system design for the MEMS mirror-based SPAD LiDAR system. The transmitter of the proposed LiDAR system consists of related optics for incident beam expansion and a piezoelectric MEMS mirror for a wide-scanning field of view. For the receiver unit, an SPAD array is utilized to collect the laser beam reflected from the target objects at a smart factory. The optical system of the proposed LiDAR system is presented, designed, and analyzed in various ways. Full article

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3 pages, 643 KiB

Open AccessAbstract

Functionalization of Indium Tin Oxide with Noble Metals Nanoparticles in Hydrogen Sensing

by Brigida Alfano, Maria Lucia Miglietta, Ettore Massera, Patricia Arroyo, Jesus Lozano and Tiziana Polichetti

Proceedings 2024, 97(1), 113; https://doi.org/10.3390/proceedings2024097113 - 25 Mar 2024

Viewed by 273

Abstract

This work presents a simple method of synthesis of hydrogen-sensitive composites, starting from commercial materials, namely ITO, Rh, Pd and Pt nanoparticles. These composites, prepared by mechanical mixture and tested vs. 0.5% H2 showed promising results at temperatures below 250 °C, in line [...] Read more.

This work presents a simple method of synthesis of hydrogen-sensitive composites, starting from commercial materials, namely ITO, Rh, Pd and Pt nanoparticles. These composites, prepared by mechanical mixture and tested vs. 0.5% H2 showed promising results at temperatures below 250 °C, in line with those obtained in the literature on similar materials, prepared with more energy- and time-consuming methods. Full article

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3 pages, 1275 KiB

Open AccessAbstract

Piezoelectric Layer Transfer Process for MEMS

by Gwenael Le Rhun, Franklin Pavageau, Timothée Rotrou, Christel Dieppedale and Laurent Mollard

Proceedings 2024, 97(1), 114; https://doi.org/10.3390/proceedings2024097114 - 27 Mar 2024

Viewed by 306

Abstract

Piezoelectric MEMS devices were fabricated on 200 mm Si wafers using both deposited and layer-transferred PZT films. In both cases, the PZT-based devices showed ferroelectric and piezoelectric properties at the level of current state-of-the-art devices. The wafer-to-wafer piezoelectric layer transfer process that was [...] Read more.

Piezoelectric MEMS devices were fabricated on 200 mm Si wafers using both deposited and layer-transferred PZT films. In both cases, the PZT-based devices showed ferroelectric and piezoelectric properties at the level of current state-of-the-art devices. The wafer-to-wafer piezoelectric layer transfer process that was developed can thus be useful to bypass the thermal budgeting issue associated with the high crystallization temperature of PZT (~700 °C). It allows the integration of PZT capacitors on any kind of layer stack or substrate, for either actuator or sensor applications. Full article

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3 pages, 2956 KiB

Open AccessAbstract

Parameters Affecting Single ZnO Nanowire Assembly by Dielectrophoresis

by Achilleas Bardakas and Christos Tsamis

Proceedings 2024, 97(1), 115; https://doi.org/10.3390/proceedings2024097115 - 27 Mar 2024

Viewed by 311

Abstract

This study aims to examine the dielectrophoretic assembly of single ZnO nanowires, focusing on the effect of electrode geometry, AC frequency and solvent medium on the alignment performance. Experimental results indicate that the electrode geometry significantly affects the capturing performance due to the [...] Read more.

This study aims to examine the dielectrophoretic assembly of single ZnO nanowires, focusing on the effect of electrode geometry, AC frequency and solvent medium on the alignment performance. Experimental results indicate that the electrode geometry significantly affects the capturing performance due to the electric field distribution. Utilizing ethanol as the solvent medium resulted in repeatable nanowire alignment at the optimal AC voltage frequency. Full article

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3 pages, 932 KiB

Open AccessAbstract

LIG/ZnO/Porphyrin-Functionalized EGFET-Based Electronic Tongue

by Kishore Pushparaj, Alexandro Catini, Rosamaria Capuano, Leonardo Papale, Valerio Allegra, Gabriele Magna, Gianni Antonelli, Eugenio Martinelli, Yuvaraj Sivalingam, Roberto Paolesse and Corrado di Natale

Proceedings 2024, 97(1), 116; https://doi.org/10.3390/proceedings2024097116 - 28 Mar 2024

Viewed by 409

Abstract

The use of laser cutter machines to produce porous graphene films is an innovative method for a low-cost production of flexible electrodes for electronics and sensing applications. Here, laser-induced graphene (LIG) is used to produce the gate electrodes of EGFET sensors. LIG electrodes [...] Read more.

The use of laser cutter machines to produce porous graphene films is an innovative method for a low-cost production of flexible electrodes for electronics and sensing applications. Here, laser-induced graphene (LIG) is used to produce the gate electrodes of EGFET sensors. LIG electrodes and LIG electrodes functionalized with ZnO and metalloporphyrin-coated ZnO are used as elements of the electronic tongue. The array is tested in a classical experiment aimed at identifying complex food matrices, such as fruit juices. The results demonstrate the feasibility of the approach and provide a solid basis for further array developments. Full article

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3 pages, 919 KiB

Open AccessAbstract

A New Hall Microdevice with Minimal Complexity

by Siya Lozanova, Avgust Ivanov, Martin Ralchev and Chavdar Roumenin

Proceedings 2024, 97(1), 117; https://doi.org/10.3390/proceedings2024097117 - 28 Mar 2024

Viewed by 337

Abstract

A new Hall microdevice with minimal complexity and orthogonal magnetic field activation is suggested. The microsensor contains a rectangular n-type silicon substrate. On the long sides, three ohmic contacts are formed symmetrically and opposite each other. The first two opposite electrodes are [...] Read more.

A new Hall microdevice with minimal complexity and orthogonal magnetic field activation is suggested. The microsensor contains a rectangular n-type silicon substrate. On the long sides, three ohmic contacts are formed symmetrically and opposite each other. The first two opposite electrodes are connected and the second two are fed in the same way, and third ones are the outputs. The increased sensitivity constituting 40 V/AT is due to the reduced parasitic surface currents. Furthermore, output electrodes are moved out of the area where the supply currents flow. The 80 × 135 μm² size of the sensor increases the resolution and provides detailed mapping of the magnetic field’s topology. Full article

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3 pages, 1211 KiB

Open AccessAbstract

Electrochemical Diffusion Study in Hydrogels

by Eva Melnik, Steffen Kurzhals, Valerio Beni, Giorgio C. Mutinati and Rainer Hainberger

Proceedings 2024, 97(1), 118; https://doi.org/10.3390/proceedings2024097118 - 28 Mar 2024

Viewed by 370

Abstract

In this study, poly(ethylene glycol) dimethacrylate (PEG-DMA)-based hydrogels were investigated with respect to the diffusion properties of methylene blue (MB) and MB conjugated proteins (MB-BSA and MB-IgG). Electrochemical sensors were used to monitor the diffusion process via the redox-active MB-label. All tested molecules [...] Read more.

In this study, poly(ethylene glycol) dimethacrylate (PEG-DMA)-based hydrogels were investigated with respect to the diffusion properties of methylene blue (MB) and MB conjugated proteins (MB-BSA and MB-IgG). Electrochemical sensors were used to monitor the diffusion process via the redox-active MB-label. All tested molecules showed good mobility in the hydrogel. Also, the release of MB-BSA could be demonstrated after drying the hydrogel containing MB-BSA, which is a promising result for the development of hydrogel-based reagent reservoirs for biosensing. Full article

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3 pages, 454 KiB

Open AccessAbstract

Effect of Heat Treatment on Electrical Insulation of Strain Sensors for Aluminum Cast Parts

by Marco Cen-Puc, Tim de Rijk, Dirk Lehmhus and Walter Lang

Proceedings 2024, 97(1), 119; https://doi.org/10.3390/proceedings2024097119 - 29 Mar 2024

Viewed by 357

Abstract

This work presents the effect of thermal treatment on the electrical insulation of strain sensors on aluminum substrates. The sensors are meant to be embedded into cast aluminum parts, which are heat-treated for strengthening via precipitation hardening. For sensor manufacturing, thick film materials [...] Read more.

This work presents the effect of thermal treatment on the electrical insulation of strain sensors on aluminum substrates. The sensors are meant to be embedded into cast aluminum parts, which are heat-treated for strengthening via precipitation hardening. For sensor manufacturing, thick film materials are used for the electrical insulation and its connection tracks, whereas sensing platinum structures are produced by sputtering. The effectiveness of different insulation thicknesses was tested for a treatment regime of 7 h at 535 °C, which matches solution heat treatment conditions as the most demanding part of the precipitation hardening process. The results showed that insulation is partially lost after treatment, and six consecutive insulating layers are required to produce an insulation capable of withstanding an extended heat treatment. Full article

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3 pages, 436 KiB

Open AccessAbstract

Preparation of Antibody-Conjugated Gold Nanotriangles for Immunochromatographic Test

by Asahi Kimura, Mao Hamamoto and Hiromasa Yagyu

Proceedings 2024, 97(1), 120; https://doi.org/10.3390/proceedings2024097120 - 29 Mar 2024

Viewed by 380

Abstract

Gold nanotriangles (GNTs) for producing a test strip of human chorionic gonadotropin (hCG) tests were reported in this paper. The GNTs were simply synthesized by non-thermal liquid-phase reduction with sodium citrate and tannic acid composition as a reducing reagent. The antibody-conjugated GNTs were [...] Read more.

Gold nanotriangles (GNTs) for producing a test strip of human chorionic gonadotropin (hCG) tests were reported in this paper. The GNTs were simply synthesized by non-thermal liquid-phase reduction with sodium citrate and tannic acid composition as a reducing reagent. The antibody-conjugated GNTs were prepared using the synthesized GNTs and anti-hCG beta antibodies. The experimental results confirmed that the use of GNTs can decrease the volume of antibodies required for the use of a labeling reagent compared with spherical GNPs for the first time. Full article

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3 pages, 423 KiB

Open AccessAbstract

Rational Design of a Planar Junctionless Field-Effect Transistor for Sensing Biomolecular Interactions

by Rajendra P. Shukla, Johan G. Bomer, Daniel Wijnperle, Naveen Kumar, Janwa El Maiss, Divya Balakrishanan, Aruna Chandra Singh, Vihar P. Georgiev, Cesar Pascual Garcia, Sivashankar Krishnamoorthy and Sergii Pud

Proceedings 2024, 97(1), 121; https://doi.org/10.3390/proceedings2024097121 - 29 Mar 2024

Viewed by 449

Abstract

In the ElectroMed project, we are interested in screening certain peptide sequences for their ability to selectively interact with antibodies or MHC proteins. This poses a combinatorial challenge that requires a highly multiplexed setup of label-free immunosensors. Label-free FET-based immunosensors are good candidates [...] Read more.

In the ElectroMed project, we are interested in screening certain peptide sequences for their ability to selectively interact with antibodies or MHC proteins. This poses a combinatorial challenge that requires a highly multiplexed setup of label-free immunosensors. Label-free FET-based immunosensors are good candidates due to their high multiplexing capability and fast response time. Nanowire-based FET sensors have shown high sensitivity but are unreliable for clinical applications due to drift and gate stability issues. To address this, a label-free immuno-FET architecture based on planar junctionless FET devices is proposed. This geometry can improve the signal-to-noise ratio due to its larger planar structure, which is less prone to defects that cause noise and is better suited to the functionalization of different receptor molecules. Full article

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3 pages, 422 KiB

Open AccessAbstract

Rapid Determination of Hexane Residues in Refined Vegetable Oils Using Semiconducting Metal Oxide-Based Sensors

by Asia Kalinichenko, Benjamin Junker, Udo Weimar and Nicolae Bârsan

Proceedings 2024, 97(1), 122; https://doi.org/10.3390/proceedings2024097122 - 29 Mar 2024

Viewed by 392

Abstract

A simple, direct method for the determination residual hexane content in refined oils was developed, which makes use of commercial Semiconducting Metal Oxides (SMOX) sensors and is proposed as an alternative to the currently used standards (ISO 9832:2002, ISO 2719:2016). The main advantages [...] Read more.

A simple, direct method for the determination residual hexane content in refined oils was developed, which makes use of commercial Semiconducting Metal Oxides (SMOX) sensors and is proposed as an alternative to the currently used standards (ISO 9832:2002, ISO 2719:2016). The main advantages are related to the direct measurement of the headspace of oil samples. The measurements are performed at an oil sample temperature of 30 °C and by spiking the samples with hexane in the 8–132 mg·kg⁻¹ range, which is in line with the requirements of current standard for the maximum residue limit set by European Union regulation. Using separate measurements performed with the help of a computer-controlled gas mixing system it is possible to determine the relationship between the concentration of hexane in oil and in the headspace. Full article

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3 pages, 166 KiB

Open AccessAbstract

Inkjet-Printed Split Ring Resonators for the Detection of Analyte Binding to a Gold Surface

by Matthias Paul, Doris Pollhammer, Christoph Mehofer, Rudolf Oberpertinger, Harald Kühnel and Markus Wellenzohn

Proceedings 2024, 97(1), 123; https://doi.org/10.3390/proceedings2024097123 - 29 Mar 2024

Viewed by 377

Abstract

This work focuses on demonstrating the working principle of inkjet-printed Au nanoparticle (NP) split-ring resonators (SRRs) as a novel platform for the detection of analytes on flexible substrates. Potential applications of this technology include rapid and reusable near-patient diagnostics. In the method, a [...] Read more.

This work focuses on demonstrating the working principle of inkjet-printed Au nanoparticle (NP) split-ring resonators (SRRs) as a novel platform for the detection of analytes on flexible substrates. Potential applications of this technology include rapid and reusable near-patient diagnostics. In the method, a microwave electromagnetic wave is coupled into the Au SRR via a printed Cu-NP stripline sintered photonically on a solid FR1 substrate. This coupling mechanism facilitates the detection of analytes by inducing resonance shifts in the SRR. To demonstrate the sensing principle of the platform, biomolecules are attached to the SRR and the resulting resonance shift is measured. All experiments show resonance frequency shifts in the range of approximately 20–30 MHz. Full article

3 pages, 3174 KiB

Open AccessAbstract

Development of Piezoelectrically Driven Quasi-Static 2D MEMS Mirrors with Extremely Large FoV for Scanning LiDARs

by Paul Raschdorf, Jeong-Yeon Hwang, Lena Wysocki, Lianzhi Wen, Jörg Albers, Gunnar Wille, Erdem Yarar and Shanshan Gu-Stoppel

Proceedings 2024, 97(1), 124; https://doi.org/10.3390/proceedings2024097124 - 29 Mar 2024

Viewed by 390

Abstract

In this paper, a piezoelectrically driven quasi-static MEMS mirror is developed for a scanning LiDAR system. Finite element method (FEM) simulations are used to optimize the design of the MEMS scanner. With special emphasis on the shape and thickness of the actuators, they [...] Read more.

In this paper, a piezoelectrically driven quasi-static MEMS mirror is developed for a scanning LiDAR system. Finite element method (FEM) simulations are used to optimize the design of the MEMS scanner. With special emphasis on the shape and thickness of the actuators, they are optimized to reach a maximum static total optical scan angle (TOSA) of 30°. Their influence on the resonance frequency at dynamic modes and the material stress are investigated. In this study, two designs are compared with respect to their FEM simulation results. Currently, the devices are manufactured in the cleanroom. The manufactured samples will be characterized and the measurement results will be published in future works. Full article

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3 pages, 1069 KiB

Open AccessAbstract

Zinc-Based Electrically Conductive Adhesive for the Transfer of SMD Components on Paper PCB

by James Bourely, Nicolas Fumeaux, Marie Sanglé-Ferrière and Danick Briand

Proceedings 2024, 97(1), 125; https://doi.org/10.3390/proceedings2024097125 - 1 Apr 2024

Viewed by 363

Abstract

We report on an eco-friendly zinc-based electrically conductive adhesive (ECA). The composition and process for the implementation of the paste to fix surface-mounted devices (SMDs) components were investigated and optimized. The ECA was used to transfer SMD resistors onto paper with printed zinc [...] Read more.

We report on an eco-friendly zinc-based electrically conductive adhesive (ECA). The composition and process for the implementation of the paste to fix surface-mounted devices (SMDs) components were investigated and optimized. The ECA was used to transfer SMD resistors onto paper with printed zinc contact pads. The stability of the paste was assessed for 1 month at room temperature with less than 1% change in resistance. Mechanical bending of SMDs bonded onto the substrate was evaluated. The paste was also implemented to fabricate a zinc paper-based RFID card. Full article

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3 pages, 711 KiB

Open AccessAbstract

ZIF-8 Films and Surface Plasmon Resonance for Chemical Vapor Detection

by Anna Estany-Macià, Ignasi Fort-Grandas, Nirav Joshi, Winnie E. Svendsen, Maria Dimaki, Albert Romano-Rodríguez and Mauricio Moreno-Sereno

Proceedings 2024, 97(1), 126; https://doi.org/10.3390/proceedings2024097126 - 1 Apr 2024

Viewed by 356

Abstract

In this paper, we present a sensor that employs Zeolitic Imidazolate Frameworks (ZIF-8) on a Surface Plasmon Resonance sensor based on diffraction gratings to detect ethanol vapors via refractive index change in the porous structure. Full article

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3 pages, 527 KiB

Open AccessAbstract

Refractive Index Sensitivity of Localized Surface Plasmon Resonance Sensor Using Gold Nanotriangles Synthesized by Seedless Non-Thermal Liquid-Phase Reduction

by Mao Hamamoto and Hiromasa Yagyu

Proceedings 2024, 97(1), 127; https://doi.org/10.3390/proceedings2024097127 - 1 Apr 2024

Viewed by 348

Abstract

This paper reported the refractive index sensing ability of localized surface plasmon resonance (LSPR) sensors using synthesized GNTs by a seedless and non-thermal synthesis method. The synthesized GNTs were a blue solution, and the edge length of the GNTs was 127 nm. The [...] Read more.

This paper reported the refractive index sensing ability of localized surface plasmon resonance (LSPR) sensors using synthesized GNTs by a seedless and non-thermal synthesis method. The synthesized GNTs were a blue solution, and the edge length of the GNTs was 127 nm. The refractive index sensitivity of the LSPR sensor using GNTs showed 162 nm/RIU, and the results confirmed that the LSPR sensor using GNTs realized high refractive index sensitivity compared with that using spherical gold nanoparticles (GNPs) with a Au concentration of 0.186 mM and a diameter of 10 nm. Full article

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3 pages, 1184 KiB

Open AccessAbstract

Screen-Printed Ceramic MEMS for Metal Oxide Gas Sensor

by Oleg Kul, Alexey Vasiliev, Andrey Nikitin, Anna Dmitrieva and Alexandr Bolshakov

Proceedings 2024, 97(1), 128; https://doi.org/10.3390/proceedings2024097128 - 1 Apr 2024

Viewed by 504

Abstract

We developed a new approach to the fabrication of MEMS (Microelectromechanical system) substrates for gas sensors. This full screen-printing approach consists in the application of sacrificial material, which is solid at the near-room temperature of printing and becomes powder after firing of the [...] Read more.

We developed a new approach to the fabrication of MEMS (Microelectromechanical system) substrates for gas sensors. This full screen-printing approach consists in the application of sacrificial material, which is solid at the near-room temperature of printing and becomes powder after firing of the elements of the sensor and, therefore, can be removed from under the suspended elements of the MEMS structure in an ultrasonic bath. The glass–ceramic MEMS is a cantilever structure equipped with a Pt-based microheater on the end edge with the sensing layer. Screen-printing provides cheap fabrication, robustness, and low power (~120 mW at 450 °C) for the sensing element. Full article

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3 pages, 3263 KiB

Open AccessAbstract

Noise Analysis of MEMS Microphones as a Gas-Sensing Element

by Gabriel Rodriguez Gutierrez and Stefan Palzer

Proceedings 2024, 97(1), 129; https://doi.org/10.3390/proceedings2024097129 - 1 Apr 2024

Viewed by 470

Abstract

In recent years, micromachined microphones have evolved into versatile transducers for gas-sensing applications in the fields of both direct and indirect photoacoustics. However, their noise properties have not yet caught much attention. In this contribution, we present an analysis of the noise spectrum [...] Read more.

In recent years, micromachined microphones have evolved into versatile transducers for gas-sensing applications in the fields of both direct and indirect photoacoustics. However, their noise properties have not yet caught much attention. In this contribution, we present an analysis of the noise spectrum of a MEMS microphone and show how it may be employed as a gas-sensing tool and to characterize photoacoustic detectors. The results highlight the potential to determine the speed of sound, ambient temperature, and gas composition via Fourier analysis of the microphone noise. Full article

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3 pages, 1442 KiB

Open AccessAbstract

Sensing Material Temperature Effect on the Multiple Gas Sensor Sensing Response

by Anze Sitar, Elia Scattolo, Matteo Valt, Alvise Bagolini, Pietro Tosato and Andrea Gaiardo

Proceedings 2024, 97(1), 130; https://doi.org/10.3390/proceedings2024097130 - 1 Apr 2024

Viewed by 348

Abstract

The temperature of the sensing material has a large impact on the tin-oxide gas sensor performance. However, the thermal analysis of gas sensors is often overlooked or only partially included in the studies. The aim of this research was to employ numerical simulations [...] Read more.

The temperature of the sensing material has a large impact on the tin-oxide gas sensor performance. However, the thermal analysis of gas sensors is often overlooked or only partially included in the studies. The aim of this research was to employ numerical simulations to investigate the temperature effect on the detection of the ethanol in an ethanol/air mixture by positioning multiple electrodes on a single heated membrane. The experimental results validated the electrothermal simulation and indicated a significant temperature effect on the sensor responsivity. Indeed, the decrease in the average sensor temperature from 427 °C to 411 °C increased the sensing response by approximately 75 % during the 5 ppm ethanol mixture flow over the sensor array. Full article

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3 pages, 448 KiB

Open AccessAbstract

UV Light Stereoselective Limonene Sensor Using Electrospun PVP Composite Nanofibers

by Antonella Macagnano, Fabricio N. Molinari, Tiziana Mancini, Stefano Lupi and Fabrizio De Cesare

Proceedings 2024, 97(1), 131; https://doi.org/10.3390/proceedings2024097131 - 1 Apr 2024

Viewed by 404

Abstract

This study explored the design of an innovative stereoselective S-(-)-limonene sensor according to the molecular imprinting polymer (MIP) strategy using UV light to generate in situ polymer cross-linking. A conductive composite nanofibrous fabric of polyvinylpyrrolidone (PVP), polyacrylic acid (PAA) and carbon nanotubes (MWCNTs) [...] Read more.

This study explored the design of an innovative stereoselective S-(-)-limonene sensor according to the molecular imprinting polymer (MIP) strategy using UV light to generate in situ polymer cross-linking. A conductive composite nanofibrous fabric of polyvinylpyrrolidone (PVP), polyacrylic acid (PAA) and carbon nanotubes (MWCNTs) was deposited on purpose in a single step by electrospinning onto interdigital microelectrodes. The nanostructured layer was investigated by microscopy (SEM, TEM, AFM) and infrared transmission measurements (FTIR). The resulting sensing features (carried out in environmental air) seemed to be mainly dependent on the peculiarity of the nanostructure and the phenomena occurring at the interfaces between the cross-linked PVP–PAA/cavity shape and MWCNTs. Furthermore, the specificity of the host–guest interaction was proven by the sensitivity, selectivity and stereoselectivity of the sensor when exposed to similar monoterpenes ((±)-α-pinene and (±)-linalool) and the enantiomer of limonene (R(+)), respectively. Full article

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3 pages, 1205 KiB

Open AccessAbstract

Sensitivity Characterization of an Impedance-Based Platform for Viability Analysis of 3D Spheroids

by Claudia Sampaio da Silva, Christian Beyer, Julia Boos, Sreedhar Kumar, Mario Modena, Thomas Valentin, Andreas Hierlemann and Vincent Revol

Proceedings 2024, 97(1), 132; https://doi.org/10.3390/proceedings2024097132 - 1 Apr 2024

Viewed by 341

Abstract

Electrical impedance spectroscopy (EIS) is a promising label-free tool for high-throughput analysis of 3D cellular constructs, also called spheroids. Here, we used an EIS platform featuring facing electrodes to characterize the viability of hepatic spheroids, which are used for bioprinting applications. By using [...] Read more.

Electrical impedance spectroscopy (EIS) is a promising label-free tool for high-throughput analysis of 3D cellular constructs, also called spheroids. Here, we used an EIS platform featuring facing electrodes to characterize the viability of hepatic spheroids, which are used for bioprinting applications. By using principal component analysis (PCA), we show that this simple impedance sensor enables us to successfully distinguish healthy spheroids from spheroids exposed to toxic conditions. The sensitivity of the impedance sensor will be further characterized by using spheroids exposed to varying stress conditions like different drug concentrations and temperatures. Full article

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3 pages, 1116 KiB

Open AccessAbstract

ZnO/WS₂ Hybrid Material, for NO₂ Detection, via the Combination of AACVD and APCVD Techniques

by Shuja Bashir Malik, Eduard Llobet and Fatima Ezahra Annanouch

Proceedings 2024, 97(1), 133; https://doi.org/10.3390/proceedings2024097133 - 1 Apr 2024

Viewed by 383

Abstract

We report for the first time the successful synthesis of ZnO/WS₂ hybrid material using a combination of aerosol-assisted chemical vapor deposition (AA-CVD) and atmospheric pressure CVD techniques. The morphology and the composition of the grown films were investigated and the results confirm [...] Read more.

We report for the first time the successful synthesis of ZnO/WS₂ hybrid material using a combination of aerosol-assisted chemical vapor deposition (AA-CVD) and atmospheric pressure CVD techniques. The morphology and the composition of the grown films were investigated and the results confirm the co-existence of both materials. Moreover, gas-sensing results against 500 ppb of NO₂ revealed the influence of WS₂ material on the ZnO gas-sensing performance. The operating temperature shifted towards lower values, from 300 °C to 150 °C. Furthermore, at room temperature, the ZnO/WS₂ sensor was able to detect NO₂ at ppb level. Full article

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3 pages, 546 KiB

Open AccessAbstract

Selectivity Enhancement of an Acetone-Monitoring SPR Sensor: Theoretical Evaluation

by Gabriel B. M. Fernandes, Villeneve O. Soares, Jefferson L. B. Marques and Cleumar S. Moreira

Proceedings 2024, 97(1), 134; https://doi.org/10.3390/proceedings2024097134 - 1 Apr 2024

Viewed by 346

Abstract

A numerical investigation of a sensor for acetone monitoring using surface plasmon resonance (SPR) is proposed. We evaluate the effects of polyaniline (PANI), graphene, or chitosan acting as a chemisorption binding layer for the selective sensing of acetone. Our findings suggest that these [...] Read more.

A numerical investigation of a sensor for acetone monitoring using surface plasmon resonance (SPR) is proposed. We evaluate the effects of polyaniline (PANI), graphene, or chitosan acting as a chemisorption binding layer for the selective sensing of acetone. Our findings suggest that these materials present suitable responses when applied as an overlayer to the sensor. Their thicknesses, however, should be maintained close to a monolayer level to preserve performance. Full article

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3 pages, 1000 KiB

Open AccessAbstract

Electrical Conductivity Sensor for Plant Substrates

by Yawar Abbas, Milou Jaspers, Rached Moalla, Joris van Nieuwstadt and Marcel A. G. Zevenbergen

Proceedings 2024, 97(1), 135; https://doi.org/10.3390/proceedings2024097135 - 1 Apr 2024

Viewed by 385

Abstract

Measuring the electrical conductivity (EC) of plant substrates is an effective way to assess their nutrient content. This study aims to compare the performance of EC sensors with varying electrode sizes and spacings when embedded in a plant substrate. The range of electrode [...] Read more.

Measuring the electrical conductivity (EC) of plant substrates is an effective way to assess their nutrient content. This study aims to compare the performance of EC sensors with varying electrode sizes and spacings when embedded in a plant substrate. The range of electrode sizes and spacings varied from 0.1 mm to 10 mm. The EC electrodes were embedded in a porous plant substrate and subjected to wet–dry cycles. The results showed that the electrodes with larger electrode dimensions and spacing produce valid EC values. Full article

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3 pages, 3142 KiB

Open AccessAbstract

The Improvement of Tamm Interface State Detection by Using a Porous Layer between a Metal Nanostructured Grating and a DBR

by Oumaima Haidar, Baptiste Mathmann, Yannick Dusch, Mohamed El Barghouti, Gaëtan Lévêque, Abdellatif Akjouj, Abdellah Mir and Abdelkrim Talbi

Proceedings 2024, 97(1), 136; https://doi.org/10.3390/proceedings2024097136 - 2 Apr 2024

Viewed by 451

Abstract

In this work, we propose a sensor based on Tamm plasmonic resonance; the structure is composed of gold nanoribbons deposited on a Distributed Bragg Reflector (DBR) (SiO₂/Si₃N₄)₆. We have enhanced the sensitivity of our sensor [...] Read more.

In this work, we propose a sensor based on Tamm plasmonic resonance; the structure is composed of gold nanoribbons deposited on a Distributed Bragg Reflector (DBR) (SiO₂/Si₃N₄)₆. We have enhanced the sensitivity of our sensor from 40 nm/RIU to 200 nm/RIU for a refractive index change of 1% by replacing the last layer of Si₃N₄ in contact with gold with porous Si₃N₄ with a porosity of p = 40%. Full article

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3 pages, 392 KiB

Open AccessAbstract

Zn-Based Triphenylene Metal–Organic Frameworks as a Chemiresistive Platform for Methane Detection

by Sachin Navale, Ignasi Fort-Grandas, Yuzelfy Mendoza, Paolo Pellegrino, Mauricio Moreno, Daniel Sainz, Anton Vidal-Ferran and Albert Romano-Rodriguez

Proceedings 2024, 97(1), 137; https://doi.org/10.3390/proceedings2024097137 - 1 Apr 2024

Viewed by 394

Abstract

Methane (CH₄) emissions are a leading cause of global warming, and precise monitoring of and reduction in these emissions are important. To achieve these goals, miniaturized low-power sensor systems with improved precision are necessary. To this end, we present a novel [...] Read more.

Methane (CH₄) emissions are a leading cause of global warming, and precise monitoring of and reduction in these emissions are important. To achieve these goals, miniaturized low-power sensor systems with improved precision are necessary. To this end, we present a novel room-temperature chemiresistive CH₄ gas sensor that employs Zn-hexahydroxytriphenylene-based metal–organic frameworks (Zn-HHTP MOFs) as detection materials. The high surface area and porosity of Zn-HHTP MOFs enable effective detection of low atmospheric levels (1.2 ppm) of CH₄. Full article

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3 pages, 1496 KiB

Open AccessAbstract

Platform for Weakly Coupled Electro-Mechanical Resonators with Arbitrary Tunability

by Ruopeng Chen, Bernardo Pereira, Chen Wang, Michael Kraft and Georges Gielen

Proceedings 2024, 97(1), 138; https://doi.org/10.3390/proceedings2024097138 - 1 Apr 2024

Viewed by 374

Abstract

This paper presents a platform for weakly coupled mechanical and electrical resonators with arbitrary tunability. Two- and three-degree-of-freedom (DoF) weakly coupled resonator systems are demonstrated experimentally with this platform, showing excellent tuning and matching flexibility. Fully electrical coupling logic circuitry gives the proposed [...] Read more.

This paper presents a platform for weakly coupled mechanical and electrical resonators with arbitrary tunability. Two- and three-degree-of-freedom (DoF) weakly coupled resonator systems are demonstrated experimentally with this platform, showing excellent tuning and matching flexibility. Fully electrical coupling logic circuitry gives the proposed system better adjustability and lower susceptibility to fabrication tolerances compared to purely mechanical weakly coupled resonators. Due to its mother/daughter board structure and the simplicity of the coupling logic, the proposed system can easily be extended to any-DoF systems. Full article

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3 pages, 328 KiB

Open AccessAbstract

Biaxial Piezoelectrically Driven MEMS Mirror with Large Design Flexibility

by Lena Wysocki, Patrick Schütt, Jörg Albers, Gunnar Wille, Erdem Yarar, Paul Raschdorf, Lianzhi Wen and Shanshan Gu-Stoppel

Proceedings 2024, 97(1), 139; https://doi.org/10.3390/proceedings2024097139 - 1 Apr 2024

Viewed by 459

Abstract

In this work, a biaxial, piezoelectrically driven resonant MEMS mirror with large design flexibility is presented. After FEM-based design optimization to reduce material stress and thereby maximize the achievable total optical scanning angles, fabricated MEMS mirrors were electrically, mechanically, and optically characterized. While [...] Read more.

In this work, a biaxial, piezoelectrically driven resonant MEMS mirror with large design flexibility is presented. After FEM-based design optimization to reduce material stress and thereby maximize the achievable total optical scanning angles, fabricated MEMS mirrors were electrically, mechanically, and optically characterized. While the achievable optical scanning angles were determined using a home-built optical setup, a laser Doppler vibrometer was used to characterize the resonance frequencies of the rotational modes and their respective quality factors. The encapsulation of the mirror by a glass window ensures its operation in vacuum, which increases the Q-factor up to 15,000. Full article

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3 pages, 390 KiB

Open AccessAbstract

Increasing Safe Water Availability via a Multisensor System for Water Monitoring and Filtration

by Anna Sabatini, Alessandro Zompanti, Simone Grasso, Marco Santonico and Giorgio Pennazza

Proceedings 2024, 97(1), 140; https://doi.org/10.3390/proceedings2024097140 - 2 Apr 2024

Viewed by 385

Abstract

The availability and quality of water have become major concerns worldwide due to the impact of climate change and pollution. To ensure safe water consumption, a monitoring and filtration system comprising a Miniwell Filter 360 passive filter, a multisensorial system with an electrochemical [...] Read more.

The availability and quality of water have become major concerns worldwide due to the impact of climate change and pollution. To ensure safe water consumption, a monitoring and filtration system comprising a Miniwell Filter 360 passive filter, a multisensorial system with an electrochemical sensor and spectrophotometer, was designed. Water samples were collected in two locations on the north coast of Rome, and analyses were conducted before and after filtration. Multivariate statistical analyses were performed to assess the instruments’ ability. The results indicate that the implemented system can increase the availability of safe water. Full article

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3 pages, 391 KiB

Open AccessAbstract

Toward Material-Integrated Wireless Electronics for SHM in Fiber Metal Laminates

by Sarah Bornemann, Liv Rittmeier, Thomas Roloff, Jan N. Haus, Christoph Polle, Axel S. Herrmann, Andreas Dietzel, Michael Sinapius, Walter Lang and Björn Lüssem

Proceedings 2024, 97(1), 141; https://doi.org/10.3390/proceedings2024097141 - 2 Apr 2024

Viewed by 409

Abstract

A self-sufficient wireless electronic sensor node for the acquisition of guided ultrasonic waves (GUW) is introduced. The system presents a step toward a structural health monitoring (SHM) system fully integrated into fiber metal laminates. It removes the need for complex wiring to transfer [...] Read more.

A self-sufficient wireless electronic sensor node for the acquisition of guided ultrasonic waves (GUW) is introduced. The system presents a step toward a structural health monitoring (SHM) system fully integrated into fiber metal laminates. It removes the need for complex wiring to transfer energy and data and reduces electromagnetic actuator excitation interference observable in wired GUW measurements. The functionality of the integrated system, e.g., to monitor the structural health of FMLs, is tested with the help of magnets used as pseudo defects. Full article

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3 pages, 1550 KiB

Open AccessAbstract

Temperature Effect of the Synthesis of Gold Nanoparticles by Microfluidics

by Sheng Shu, Mao Hamamoto and Hiromasa Yagyu

Proceedings 2024, 97(1), 142; https://doi.org/10.3390/proceedings2024097142 - 2 Apr 2024

Viewed by 448

Abstract

We clarified the effect of mixing temperature on the synthesis of gold nanoparticles by a microfluidic device using tannic acid and citric acid as reducing reagents. In this study, gold nanoparticles were synthesized on the microfluidic device with a flow rate of 0.05 [...] Read more.

We clarified the effect of mixing temperature on the synthesis of gold nanoparticles by a microfluidic device using tannic acid and citric acid as reducing reagents. In this study, gold nanoparticles were synthesized on the microfluidic device with a flow rate of 0.05 mL/min at the temperature of room temperature (23 °C) and 80 °C. The results confirmed that the mean diameter and coefficient of variation of gold nanoparticles synthesized at 80 °C were 13.7 nm and 0.28 and the coefficient of variation increased by 65% in comparison with that at room temperature. Full article

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3 pages, 336 KiB

Open AccessAbstract

Indoor Air Quality CO₂ Thermally Modulated SMR Sensor

by Siavash Esfahani, Thomas Dawson, Barbara Urasinska Wojcik, Marina Cole and Julian W. Gardner

Proceedings 2024, 97(1), 143; https://doi.org/10.3390/proceedings2024097143 - 2 Apr 2024

Viewed by 350

Abstract

This paper reports on a CO₂ solidly mounted resonator (SMR)-based sensor with an integrated heater. The SMR device is CMOS compatible and operates at a resonant frequency of 2 GHz. To increase the sensitivity and selectivity, the SMR devices were functionalized with [...] Read more.

This paper reports on a CO₂ solidly mounted resonator (SMR)-based sensor with an integrated heater. The SMR device is CMOS compatible and operates at a resonant frequency of 2 GHz. To increase the sensitivity and selectivity, the SMR devices were functionalized with a 20 μm CO₂ sensitive layer. Two SMR sensors were employed in a differential configuration; one sensor was uncoated and used as a reference and the other was coated and used as a sensing device. The frequency shift of ~8 kHz/% CO₂ in dry air was observed after temperature and humidity compensation; demonstrating its potential application in indoor air quality (IAQ) monitoring. Full article

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3 pages, 2560 KiB

Open AccessAbstract

A Comprehensive Characterization Procedure for Resonant MEMS Scanning Mirrors

by Clement Fleury, Markus Bainschab, Gianluca Mendicino, Roberto Carminati, Pooja Thakkar, Dominik Holzmann, Sara Guerreiro and Adrien Piot

Proceedings 2024, 97(1), 144; https://doi.org/10.3390/proceedings2024097144 - 3 Apr 2024

Viewed by 488

Abstract

We demonstrate an experimental assessment of a high-Q, high-angle piezoelectric (2 µm PZT) MEMS scanning micromirror featuring distributed backside reinforcement, suitable for applications demanding energy-efficient and high-quality image projection. Frequency response measurements at 10 different vacuum levels ranging from atmospheric pressure to 10 [...] Read more.

We demonstrate an experimental assessment of a high-Q, high-angle piezoelectric (2 µm PZT) MEMS scanning micromirror featuring distributed backside reinforcement, suitable for applications demanding energy-efficient and high-quality image projection. Frequency response measurements at 10 different vacuum levels ranging from atmospheric pressure to 10⁻⁶ mbar allow for the quantitative separation of damping mechanisms (air and structural). Stroboscopic digital holographic microscopy was used to assess the static and dynamic deformation of the mirror surface. The experimental results are in good agreement with simulations and models. Full article

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3 pages, 403 KiB

Open AccessAbstract

Electronic Nose for Early Diagnosis of Ovarian Cancer

by Jens Eriksson, Donatella Puglisi and Christer Borgfeldt

Proceedings 2024, 97(1), 145; https://doi.org/10.3390/proceedings2024097145 - 3 Apr 2024

Viewed by 476

Abstract

We present an electronic nose that detects ovarian cancer based on gas emissions from blood plasma. There is currently no test available for screening or diagnostic testing of this disease, which is therefore often detected at aa late stage, resulting in a poor [...] Read more.

We present an electronic nose that detects ovarian cancer based on gas emissions from blood plasma. There is currently no test available for screening or diagnostic testing of this disease, which is therefore often detected at aa late stage, resulting in a poor prognosis. Our approach correctly detected 85 out of 87 ovarian cancers, ranging from borderline to stage IV. Full article

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2 pages, 458 KiB

Open AccessAbstract

Room Temperature CO₂ Detection by Metal Oxide-Based Nanosensors

by José Pedro Santos, Isabel Sayago and Júlia González

Proceedings 2024, 97(1), 146; https://doi.org/10.3390/proceedings2024097146 - 3 Apr 2024

Viewed by 432

Abstract

Carbon dioxide is considered a greenhouse gas and is the main cause of global warming. CO₂ emissions have increased more and more each year. It is therefore important to be able to detect these levels of CO₂ at room temperature. Chemical [...] Read more.

Carbon dioxide is considered a greenhouse gas and is the main cause of global warming. CO₂ emissions have increased more and more each year. It is therefore important to be able to detect these levels of CO₂ at room temperature. Chemical sensors consisting of FR-4 substrates with four membranes on which Fe₂O₃, SnO₂, ZnO, and CuO nanoparticles have been deposited, were used in this experiment. The method used to create the sensors was the drop-casting technique. Two types of experiments were performed using these sensors, with each measurement considering a relative humidity value of either 0% or 50% in air. Based on the results, we have observed a significant improvement in detection for measurements with humidity. These sensors can detect concentration as low as 250 ppm with 50% humidity, compared to 700 ppm without humidity in air. Full article

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3 pages, 872 KiB

Open AccessAbstract

Resistive Gas Dosimeters as a Novel Method to Measure Small Gas Concentrations and Quantities, Both Accumulative and Timely Resolved

by Ralf Moos, Andrea Groß and Daniela Schönauer-Kamin

Proceedings 2024, 97(1), 147; https://doi.org/10.3390/proceedings2024097147 - 3 Apr 2024

Viewed by 427

Abstract

Resistive gas dosimeters are a novel method to accurately measure timely intervals like hourly mean values even for small gas concentrations. This measuring principle overcomes the disadvantageously low recovery times of conventional chemiresistive sensors. Applications for the detection of nitrogen oxides in ambient [...] Read more.

Resistive gas dosimeters are a novel method to accurately measure timely intervals like hourly mean values even for small gas concentrations. This measuring principle overcomes the disadvantageously low recovery times of conventional chemiresistive sensors. Applications for the detection of nitrogen oxides in ambient air in the ppb range demonstrate the feasibility. Full article

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3 pages, 1114 KiB

Open AccessAbstract

Printed PEDOT:PSS Sensing Labels for Real-Time Monitoring of Hydrogen Peroxide Vapors

by Silvia Demuru, Jaemin Kim, Martin Novák, Gregor Hommes and Danick Briand

Proceedings 2024, 97(1), 148; https://doi.org/10.3390/proceedings2024097148 - 3 Apr 2024

Viewed by 451

Abstract

This work reports on printed organic PEDOT:PSS sensors for the detection of hydrogen peroxide (H₂O₂) vapors. Compared to commercial devices, the proposed sensors are thin and flexible, allowing their simple integration into an industrial process for multilocation decontamination monitoring. [...] Read more.

This work reports on printed organic PEDOT:PSS sensors for the detection of hydrogen peroxide (H₂O₂) vapors. Compared to commercial devices, the proposed sensors are thin and flexible, allowing their simple integration into an industrial process for multilocation decontamination monitoring. The sensors show a reproducible behavior in a laboratory environment using chambers containing a concentration of 130 ppm of H₂O₂, measuring an increase in resistance of ~1200% for 1 h exposure. The results highlight the importance of contact interfaces and their encapsulation for reproducible sensing behavior. These devices are promising as low-cost disposable devices for decontamination process monitoring. Full article

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3 pages, 526 KiB

Open AccessAbstract

Systematic Experimental Evaluation of Submilliwatt PV Cells for Indoor Applications

by Eduard Ferré, Marc Azlor, Manel Gasulla and Ferran Reverter

Proceedings 2024, 97(1), 149; https://doi.org/10.3390/proceedings2024097149 - 3 Apr 2024

Viewed by 401

Abstract

In the context of energy harvesting for tiny autonomous sensors placed indoors, this work carries out a systematic experimental evaluation of low-power, low-area photovoltaic (PV) cells. The evaluation involves several cell technologies and types of illumination and, for each technology–illumination pair, a sweep [...] Read more.

In the context of energy harvesting for tiny autonomous sensors placed indoors, this work carries out a systematic experimental evaluation of low-power, low-area photovoltaic (PV) cells. The evaluation involves several cell technologies and types of illumination and, for each technology–illumination pair, a sweep of different levels of illuminance and temperature expected indoors is performed. The information extracted from this work will enable a better selection of the cell technology for a given type of indoor illumination, and a better design of the ensuing maximum power point (MPP) tracker oriented to the cell technology–illumination pair. Full article

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3 pages, 367 KiB

Open AccessAbstract

The Role of Convection and Size Effects in Sensor Microhotplate Heat Exchange

by Alexey Vasiliev, Alexey Shaposhnik and Oleg Kul

Proceedings 2024, 97(1), 150; https://doi.org/10.3390/proceedings2024097150 - 3 Apr 2024

Viewed by 424

Abstract

The analysis of the influence of microhotplate size on the convective heat exchange of gas sen-sors is presented. It is demonstrated that there is a minimum size leading to the formation of convection heat exchange flow. Below this minimum, only the thermal conductivity [...] Read more.

The analysis of the influence of microhotplate size on the convective heat exchange of gas sen-sors is presented. It is demonstrated that there is a minimum size leading to the formation of convection heat exchange flow. Below this minimum, only the thermal conductivity of ambient air and IR radiation should be considered as channels for heat dissipation by microhotplate. This limit expression contains only fundamental constants of air,

d ~ 4 \cdot \sqrt[3]{\frac{ν \cdot D}{g}}

, where ν is the kinematic viscosity of air, D is the diffusion coefficient, and g is the acceleration of free fall, d~0.5 cm. Full article

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3 pages, 816 KiB

Open AccessAbstract

Freeform Optimization of an Ultrasonic Horn Coupled to an Airborne MEMS Transducer

by Gabriele Bosetti, Stefan Hofstetter-Spona and Gabriele Schrag

Proceedings 2024, 97(1), 151; https://doi.org/10.3390/proceedings2024097151 - 8 Apr 2024

Viewed by 327

Abstract

We designed an ultrasonic horn using a physics-based freeform optimization method to achieve the target frequency response of an airborne ultrasonic MEMS transducer operating in transmitting mode. The radial profile of the ultrasonic horn was parametrized using a Bezier curve, and its shape [...] Read more.

We designed an ultrasonic horn using a physics-based freeform optimization method to achieve the target frequency response of an airborne ultrasonic MEMS transducer operating in transmitting mode. The radial profile of the ultrasonic horn was parametrized using a Bezier curve, and its shape was optimized using a genetic algorithm. A computationally fast compact model of the full system, wherein the horn was described analytically using transmission line theory, was used to calculate the frequency response of the transducer and evaluate the optimization objective. The result shows very good agreement with the experimental measurement of a realized prototype. Full article

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2 pages, 169 KiB

Open AccessAbstract

Swelling Behavior of an Ethanol-Sensitive Hydrogel Immobilized on a Plasmonic Sensor Substrate

by Julia Herzog, Martin Sobczyk, Marisa Rio, Christiane Schuster, Thomas Härtling and Gerald Gerlach

Proceedings 2024, 97(1), 152; https://doi.org/10.3390/proceedings2024097152 - 5 Apr 2024

Viewed by 299

Abstract

Refractive index-sensitive plasmonic sensors are suitable for the on-site detection of fluid parameters in process engineering applications. The functionalization of optically sensitive nanostructured surfaces with stimuli-responsive hydrogels enables the selective determination of parameters of complex liquids. Thereby, the degree of swelling of the [...] Read more.

Refractive index-sensitive plasmonic sensors are suitable for the on-site detection of fluid parameters in process engineering applications. The functionalization of optically sensitive nanostructured surfaces with stimuli-responsive hydrogels enables the selective determination of parameters of complex liquids. Thereby, the degree of swelling of the hydrogel gives indications to liquid parameters like pH or molecule concentrations. In this study, the influence of the swelling degree of an immobilized ethanol-sensitive hydrogel on the sensor signal is investigated. The application of both a measuring and reference area allows differentiation of the refractive index change induced by the swelling effect from the refractive index change of the analyte due to concentration changes. Full article

3 pages, 1114 KiB

Open AccessAbstract

Flexible, Fan-Out, Wafer-Level Packaging Using Polydimethylsiloxane and Printed Redistribution Layers

by Muhammad Hassan Malik, Muhammad Khan, Sherjeel Khan and Ali Roshanghias

Proceedings 2024, 97(1), 153; https://doi.org/10.3390/proceedings2024097153 - 7 Apr 2024

Viewed by 360

Abstract

The hybrid integration of electronics in flexible substrates using fanned-out, wafer-level packaging (FOWLP) has recently gained significant attention, with numerous applications in wearable electronics, foldable displays, robotics, medical implants, and healthcare monitoring. In this study, a fully additive and scalable manufacturing process flow [...] Read more.

The hybrid integration of electronics in flexible substrates using fanned-out, wafer-level packaging (FOWLP) has recently gained significant attention, with numerous applications in wearable electronics, foldable displays, robotics, medical implants, and healthcare monitoring. In this study, a fully additive and scalable manufacturing process flow to realize a low-cost, flexible FOWLP system was introduced. Here, the integration of 36 LED chips in a biocompatible polydimethylsiloxane (PDMS) substrate was demonstrated using a stencil-printed silver (Ag) redistribution layer (RDL). The processes for the integration of chips, i.e., chip first (exposed die embedding), chip first (deep embedding with filled valleys) and chip last (RDL first), were implemented, and the corresponding samples were evaluated electrically. The bendability of the samples was also characterized at different bending diameters. Conclusively, it was shown that by using surface-modified PDMS as a flexible substrate and stretchable Ag paste as interconnect, flexible FOWLP can be produced. Full article

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3 pages, 518 KiB

Open AccessAbstract

Plasmonic Nanopores as Tunable Optical Platforms for Single-Molecule Detection

by Adriano Colombelli, Daniela Lospinoso and Maria Grazia Manera

Proceedings 2024, 97(1), 154; https://doi.org/10.3390/proceedings2024097154 - 7 Apr 2024

Viewed by 341

Abstract

Tunable plasmonic nanostructures are of the utmost importance in sensing applications due to their ability to precisely manipulate and control light–matter interactions at the nanoscale. The easy control of geometrical features enables the optimization of their optical properties, such as the resonance frequency, [...] Read more.

Tunable plasmonic nanostructures are of the utmost importance in sensing applications due to their ability to precisely manipulate and control light–matter interactions at the nanoscale. The easy control of geometrical features enables the optimization of their optical properties, such as the resonance frequency, intensity, and spectral width, to match the specific requirements of the sensing system. Enhanced sensing performances are thus achieved in terms of the sensitivity and selectivity towards target analytes, leading to improved detection limits and accuracy. Additionally, tunable plasmonic nanostructures offer the flexibility to adapt to different sensing conditions and analytes, making them versatile platforms for a wide range of sensing applications. In this work, a low-cost and optimized fabrication protocol was developed to realize highly ordered nanopores in thin gold films with tunable plasmonic features. Performances of the realized nanostructures were tested by different metal-enhanced spectroscopies, in particular Surface-Enhanced Raman Spectroscopies. Full article

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3 pages, 1604 KiB

Open AccessAbstract

High-Frequency Grating-Based Microelectromechanical Systems Actuator

by Inês Pires, Inês S. Garcia, João Vieira, Zeev Zalevsky, Carlos Calaza, Filipe S. Alves and Rosana A. Dias

Proceedings 2024, 97(1), 155; https://doi.org/10.3390/proceedings2024097155 - 7 Apr 2024

Viewed by 344

Abstract

A silicon mechanical-photonic wavelength converter, not based on absorption, has been recently proposed to address the need for all-silicon photodetectors in the infrared spectrum. Its implementation requires high-frequency modulation, from hundreds of kHz to 1 MHz, of a light beam over an area [...] Read more.

A silicon mechanical-photonic wavelength converter, not based on absorption, has been recently proposed to address the need for all-silicon photodetectors in the infrared spectrum. Its implementation requires high-frequency modulation, from hundreds of kHz to 1 MHz, of a light beam over an area of a few hundred microns. Since the displacement amplitudes of tens of microns at these frequencies are unfeasible, a moving grate is proposed to locally modulate the light. The MEMS actuator, an array of 1 µm-wide 1 µm-spaced beams (100 × 100 µm² area), achieved displacements of 70 nm at atmospheric pressure and 350 nm under low vacuum, with 10 Vpp actuation at 290 kHz (FOM displacement × frequency² above previously reported works). Full article

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3 pages, 1172 KiB

Open AccessAbstract

Towards Next-Generation Glucose Sensors: Reactively Sputtered Nanostructured Nickel Nitrides for CMOS Integration

by Filippo Franceschini, Catarina Fernandes and Irene Taurino

Proceedings 2024, 97(1), 156; https://doi.org/10.3390/proceedings2024097156 - 7 Apr 2024

Viewed by 328

Abstract

A facile and clean-room compatible approach to Ni nitride (Ni_xN_y) synthesis is proposed, based on a reactive sputtering deposition technique. Ni_xN_y thin films were deposited at different N₂ partial pressures, after which their electrocatalytic properties [...] Read more.

A facile and clean-room compatible approach to Ni nitride (Ni_xN_y) synthesis is proposed, based on a reactive sputtering deposition technique. Ni_xN_y thin films were deposited at different N₂ partial pressures, after which their electrocatalytic properties towards glucose oxidation were investigated. Relative to the bare Ni, Ni_xN_y thin films sputtered at low N₂ partial pressures exhibited a decreased linear range (0–5 mM) and sensitivity. Contrarily, Ni_xN_y thin films sputtered at high N₂ partial pressures displayed an increase in sensitivity of ≈30% in the same linear range (0–10 mM) as for Ni. The Ni_xN_y films showed a clear morphological change from a flat thin film (Ni) to a faceted nanostructure whose characteristic dimensions decreased with increasing N₂. Full article

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3 pages, 600 KiB

Open AccessAbstract

Questioning Breath: A Digital Dive into CO₂ Levels

by Silvia Casalinuovo, Alessio Buzzin, Antonio Mastrandrea, Marcello Barbirotta, Donatella Puglisi, Giampiero de Cesare and Domenico Caputo

Proceedings 2024, 97(1), 157; https://doi.org/10.3390/proceedings2024097157 - 7 Apr 2024

Viewed by 330

Abstract

This work presents a smart mask for real-time monitoring of carbon dioxide (CO₂) levels as a reference tool for diagnosis, sports training and mental health status. A printed circuit board was projected and fabricated to gain data with real-time visualization and [...] Read more.

This work presents a smart mask for real-time monitoring of carbon dioxide (CO₂) levels as a reference tool for diagnosis, sports training and mental health status. A printed circuit board was projected and fabricated to gain data with real-time visualization and storage on a database, enabling remote monitoring as a needed skill for telemedicine purposes. The electronics were inserted in a wearable device—shaped like a mask—and 3D-printed with biocompatible materials. The whole device was used for analyzing CO₂ on a breath volunteer in three kinds of measurement. Full article

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3 pages, 2464 KiB

Open AccessAbstract

Transparent PZT Capacitors on Glass for Actuating Applications

by Franklin Pavageau, Christel Dieppedale, Kevin Benedetto, Christophe Licitra, Laurent Frey, Fabrice Casset and Gwenaël Le Rhun

Proceedings 2024, 97(1), 158; https://doi.org/10.3390/proceedings2024097158 - 7 Apr 2024

Viewed by 316

Abstract

Fully integrated transparent ITO/PZT/ITO capacitors on glass were obtained thanks to a recently developed wafer-to-wafer layer-transfer process to bypass the thermal budget issue associated with the high crystallization temperature of PZT (~700 °C). The fabricated devices show an average transparency of around 80% [...] Read more.

Fully integrated transparent ITO/PZT/ITO capacitors on glass were obtained thanks to a recently developed wafer-to-wafer layer-transfer process to bypass the thermal budget issue associated with the high crystallization temperature of PZT (~700 °C). The fabricated devices show an average transparency of around 80% (and up to 94%) in the visible spectrum thanks to the use of SiO₂ passivation acting as an anti-reflector and a transverse piezoelectric coefficient of up to 10.25 C/m², which is suitable for the actuating purpose. The actuation of a vibrating glass plate (3.12 cm × 3.12 cm) was highlighted using a PZT capacitor (35.9 mm²) in agreement with the modeling. Full article

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3 pages, 575 KiB

Open AccessAbstract

Light-Emitting Silicon Nanowires (Si NWs) as a Novel Sensing Platform for SARS-CoV-2 Detection

by Antonio Alessio Leonardi, Emanuele Luigi Sciuto, Maria José Lo Faro, Barbara Fazio, Maria Giovanna Rizzo, Luca Francioso, Rosaria Anna Picca, Francesco Nastasi, Alessia Irrera and Sabrina Conoci

Proceedings 2024, 97(1), 159; https://doi.org/10.3390/proceedings2024097159 - 7 Apr 2024

Viewed by 332

Abstract

Silicon nanowires (Si NWs) are considered an outstanding material for several applications. We have realized quantum-confined and room-temperature luminescent Si NWs. These Si NWs exhibit a high-aspect ratio, and high sensitive and selective label-free detection has been demonstrated for proteins, small extracellular vesicles, [...] Read more.

Silicon nanowires (Si NWs) are considered an outstanding material for several applications. We have realized quantum-confined and room-temperature luminescent Si NWs. These Si NWs exhibit a high-aspect ratio, and high sensitive and selective label-free detection has been demonstrated for proteins, small extracellular vesicles, and DNAs. The realization of a SARS-CoV-2 Si NW sensor able to detect a few virus copies and remain unaffected by the variant (such as Omicron) is reported, paving the way for new, cheap, optical label-free devices for the primary health care diagnosis with an industrially compatible approach. Full article

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3 pages, 648 KiB

Open AccessAbstract

3D Bioprinted Hydrogel Sensor towards Rapid Salivary Diagnostics Based on pH Colorimetric Detection

by Magdalena Beata Łabowska, Agnieszka Krakos (Podwin) and Wojciech Kubicki

Proceedings 2024, 97(1), 160; https://doi.org/10.3390/proceedings2024097160 - 7 Apr 2024

Viewed by 365

Abstract

In this paper, a novel solution of 3D bioprinted hydrogel sensor towards rapid diagnostics of saliva based on pH colorimetric detection is proposed. The hydrogel ink of unique composition of sodium alginate and polyvinylpyrrolidone was developed and printed on biocompatible substrates to achieve [...] Read more.

In this paper, a novel solution of 3D bioprinted hydrogel sensor towards rapid diagnostics of saliva based on pH colorimetric detection is proposed. The hydrogel ink of unique composition of sodium alginate and polyvinylpyrrolidone was developed and printed on biocompatible substrates to achieve a repeatable and robust sensor structure. A colorimetric method was applied to visualize the hydrogel color tunability in a pH range of 5.5–7.5. The biosensor calibration curve was determined showing appropriate performance, as well as experiments with artificial saliva samples containing green tea in different proportions were conducted. Full article

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2 pages, 394 KiB

Open AccessAbstract

Sensor Protection Caps: Development Aspects and Verification

by Gunter Hagen, Julia Herrmann, Thomas Kern, Thomas Wöhrl and Ralf Moos

Proceedings 2024, 97(1), 161; https://doi.org/10.3390/proceedings2024097161 - 8 Apr 2024

Viewed by 339

Abstract

High-temperature gas sensors are often affected by non-constant ambient conditions, especially with respect to mass flow variations. Steady operation conditions are essential for attaining stable results. So, appropriate protection caps must provide an optimum level of gas access to the sensors’ functional structures [...] Read more.

High-temperature gas sensors are often affected by non-constant ambient conditions, especially with respect to mass flow variations. Steady operation conditions are essential for attaining stable results. So, appropriate protection caps must provide an optimum level of gas access to the sensors’ functional structures to allow for a sufficient response but also maximal homogeneity. Therefore, cap design was carried out through modelling and simulations. For verification, we used a specially developed sensor structure with screen-printed thermocouples to measure temperature homogeneity inside individually designed caps, which were created via additive manufacturing. Full article

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3 pages, 1551 KiB

Open AccessAbstract

Embedded Sensing System for Wireless Sleep Apnea Monitoring

by Gabriel Rodriguez Gutierrez, Chenchen Shen, Daniel Rau, Alvaro Ortiz Perez, Jürgen Götze and Stefan Palzer

Proceedings 2024, 97(1), 162; https://doi.org/10.3390/proceedings2024097162 - 8 Apr 2024

Viewed by 343

Abstract

Sleep apnea syndrome is a breathing disorder with a prevalence exceeding 20% in the overall population, and it can seriously affect health and well-being. However, this condition usually remains undetected because suitable monitoring solutions are lacking. This contribution presents an approach to facilitate [...] Read more.

Sleep apnea syndrome is a breathing disorder with a prevalence exceeding 20% in the overall population, and it can seriously affect health and well-being. However, this condition usually remains undetected because suitable monitoring solutions are lacking. This contribution presents an approach to facilitate apnea diagnosis using a battery-powered, wireless, miniaturized sensing system embedded in a patient’s mask. It combines a photoacoustic-based carbon dioxide detector with temperature and humidity sensors as well as embedded algorithms to automatically detect apnea episodes. The results show the feasibility of detecting apnea using an easily deployable analysis system. Full article

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2 pages, 361 KiB

Open AccessAbstract

TinyML with Meta-Learning on Microcontrollers for Air Pollution Prediction

by I Nyoman Kusuma Wardana, Suhaib A. Fahmy and Julian W. Gardner

Proceedings 2024, 97(1), 163; https://doi.org/10.3390/proceedings2024097163 - 8 Apr 2024

Viewed by 365

Abstract

Tiny machine learning (tinyML) involves the application of ML algorithms on resource-constrained devices such as microcontrollers. It is possible to improve tinyML performance by using a meta-learning approach. In this work, we proposed lightweight base models running on a microcontroller to predict air [...] Read more.

Tiny machine learning (tinyML) involves the application of ML algorithms on resource-constrained devices such as microcontrollers. It is possible to improve tinyML performance by using a meta-learning approach. In this work, we proposed lightweight base models running on a microcontroller to predict air pollution and show how performance can be improved using a stacking ensemble meta-learning method. We used an air quality dataset for London. Deployed on a Raspberry Pi Pico microcontroller, the tinyML file sizes were 3012 bytes and 5076 bytes for the two base models we proposed. The stacked model could achieve RMSE improvements of up to 4.9% and 14.28% when predicting NO₂ and PM_2.5, respectively. Full article

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3 pages, 885 KiB

Open AccessAbstract

Self-Diagnostic Method for Resistive Displacement Sensors

by Federico Mazzoli, Davide Alghisi and Vittorio Ferrari

Proceedings 2024, 97(1), 164; https://doi.org/10.3390/proceedings2024097164 - 8 Apr 2024

Cited by 1 | Viewed by 331

Abstract

Displacement sensors play a key role in the control of dynamic processes. Such sensors can be endowed with self-diagnostic capabilities to identify both the degradation of their conditions and the possible process anomalies that caused them, thus allowing researchers to monitor the process [...] Read more.

Displacement sensors play a key role in the control of dynamic processes. Such sensors can be endowed with self-diagnostic capabilities to identify both the degradation of their conditions and the possible process anomalies that caused them, thus allowing researchers to monitor the process efficiency and therefore its sustainability. Within this scope, a self-diagnostic method is proposed to infer the conditions of a resistive displacement sensor by estimating its model parameters online during operation. Experimental results confirm the effectiveness of the presented method. Full article

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3 pages, 572 KiB

Open AccessAbstract

Selective Detection of Toxic Gases by Arrays of Single-Layer Graphene Sensors Functionalized with Nanolayers of Different Oxides

by Margus Kodu, Martin Lind, Valter Kiisk, Indrek Renge and Raivo Jaaniso

Proceedings 2024, 97(1), 165; https://doi.org/10.3390/proceedings2024097165 - 8 Apr 2024

Viewed by 309

Abstract

Graphene provides an ideal platform for chemiresistive gas sensors as the material is fully exposed to the surrounding environment. For practical use in an ambient atmosphere, its sensitivity and selectivity should be evoked by functionalization by defects and dopants or by decoration with [...] Read more.

Graphene provides an ideal platform for chemiresistive gas sensors as the material is fully exposed to the surrounding environment. For practical use in an ambient atmosphere, its sensitivity and selectivity should be evoked by functionalization by defects and dopants or by decoration with nanophases of metals or metal oxides. Here, we demonstrate a few successful cases of selectivity enhancement by functionalizing the graphene with different oxide layers and applying machine learning to the resulting sensor array. Full article

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3 pages, 1374 KiB

Open AccessAbstract

Integration of a Bead-Based Immunoassay on a Commercial PCR-Performing POC Device

by Benita Johannsen, Desirée Baumgartner, Michal Karpíšek, David Stejskal, Nils Paust, Roland Zengerle and Konstantinos Mitsakakis

Proceedings 2024, 97(1), 166; https://doi.org/10.3390/proceedings2024097166 - 8 Apr 2024

Viewed by 340

Abstract

Point-of-care (POC) infectious disease diagnostic devices typically detect either only pathogens or only protein biomarkers, while they provide a low throughput of samples (one to two) tested per run. In this work, we demonstrate the adaptation of a bead-based competitive immunoassay method to [...] Read more.

Point-of-care (POC) infectious disease diagnostic devices typically detect either only pathogens or only protein biomarkers, while they provide a low throughput of samples (one to two) tested per run. In this work, we demonstrate the adaptation of a bead-based competitive immunoassay method to be compatible with a commercial POC PCR-performing device without modifications to its hardware. In addition, the assay integration in two half disk-shaped cartridges with seven identical structures on each provides a considerable throughput of 14 samples per 20 min run. Full article

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3 pages, 689 KiB

Open AccessAbstract

Measuring the Thermal Conductivity of Humid Air over a Broad Temperature and Water Content Range

by Hans-Fridtjof Pernau, Mike Benkendorf, Martin Jägle, Stephan Heinrich, Thorsten Knittel and Jürgen Wöllenstein

Proceedings 2024, 97(1), 167; https://doi.org/10.3390/proceedings2024097167 - 8 Apr 2024

Viewed by 345

Abstract

The knowledge of the thermal conductivity of humid air between 0 and 100 °C and 0 and 100% relative humidity is of great interest for various applications. However, direct measurement of the thermal conductivity of gaseous substances is challenging. Using an adapted version [...] Read more.

The knowledge of the thermal conductivity of humid air between 0 and 100 °C and 0 and 100% relative humidity is of great interest for various applications. However, direct measurement of the thermal conductivity of gaseous substances is challenging. Using an adapted version of the 3-omega method, we show that direct measurement is possible within a reasonable error limit. Full article

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3 pages, 1022 KiB

Open AccessAbstract

Cu Ferrospinel Thin Films for Sub-ppm NO₂ Sensing

by Sabah Zahaf, Lionel Presmanes, Antoine Barnabé, Thierry Camps and Philippe Menini

Proceedings 2024, 97(1), 168; https://doi.org/10.3390/proceedings2024097168 - 9 Apr 2024

Viewed by 332

Abstract

The paper reports the synthesis and characterization of a copper ferrospinel thin layer. The thin layer (25 nm) was synthesized by RF sputtering of a pure CuFe₂O₄ target. The material structure and microstructure were characterized using X-ray diffraction and transmission [...] Read more.

The paper reports the synthesis and characterization of a copper ferrospinel thin layer. The thin layer (25 nm) was synthesized by RF sputtering of a pure CuFe₂O₄ target. The material structure and microstructure were characterized using X-ray diffraction and transmission electron microscopy. Simplified test substrates were microfabricated with interdigitated Pt electrodes to investigate electrical properties in a controlled atmosphere. The sensitive layer was stabilized by annealing at 550 °C under air. NO₂ responses at a low concentration (<1 ppm) and 50% relative humidity were measured between 100 and 500 °C. The optimal response was obtained at 250 °C. Full article

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2 pages, 156 KiB

Open AccessAbstract

Gas Sensors: A Non-Contact and Non-Invasive Solution for Checking the Hydraulic Fluid Degradation

by Ambra Fioravanti, Pietro Marani, Luigi Sequino, Fulvio Palmieri, Francesca Rapparini, Achill Holzer, Zita Tappeiner, Katharina Schmitz, Sara Morandi, Stefano Lettieri and Maria Cristina Carotta

Proceedings 2024, 97(1), 169; https://doi.org/10.3390/proceedings2024097169 - 9 Apr 2024

Viewed by 339

Abstract

Chemiresistive gas sensors based on metal oxide (MOX) semiconductors are attractive devices used to detect gaseous compounds in many applications. In fluid power systems, they could be exploited to monitor the odor changes of the hydraulic fluid that occur with aging. In this [...] Read more.

Chemiresistive gas sensors based on metal oxide (MOX) semiconductors are attractive devices used to detect gaseous compounds in many applications. In fluid power systems, they could be exploited to monitor the odor changes of the hydraulic fluid that occur with aging. In this work, an extensive investigation has been performed for many kinds of hydraulic fluids aged in different conditions with the aim to develop a portable device to be installed in every system for performing predictive maintenance increasing system efficiency, reliability, and sustainability. Full article

3 pages, 317 KiB

Open AccessAbstract

Surface Enhanced Raman Scattering (SERS) for the Detection of Oxidative Stress Markers Using Si Nanowires (SiNWs)/Ag Nanostructures Fabricated by Metal Assisted Chemical Etching (MACE)

by Ioannis Kochylas, Anastasia Kanioura, Georgia Geka, Vlassios Likodimos, Spiros Gardelis, Anastasios Dimitriou, Nikolaos Papanikolaou, Sotirios Kakabakos and Panagiota Petrou

Proceedings 2024, 97(1), 170; https://doi.org/10.3390/proceedings2024097170 - 9 Apr 2024

Viewed by 386

Abstract

In this work, silicon nanowires were constructed by metal-assisted chemical etching and decorated with silver nanoparticles and used as substrates for the SERS determination of oxidative stress markers, namely glutathione, malondialdehyde and catalase. The assays were sensitive, with detection limits of 50 and [...] Read more.

In this work, silicon nanowires were constructed by metal-assisted chemical etching and decorated with silver nanoparticles and used as substrates for the SERS determination of oxidative stress markers, namely glutathione, malondialdehyde and catalase. The assays were sensitive, with detection limits of 50 and 3.2 nM for glutathione and malondialdehyde, respectively, and 0.5 μg/mL for catalase, indicating the capability of the proposed substrates to be implemented for the determination of various oxidative stress markers. Full article

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3 pages, 999 KiB

Open AccessAbstract

SiO₂/Platinum Monolith Aerogels Realized in Closed µfluidic Channels

by Ana Luiza Silveira Fiates, Oliver Thüringer, Thorsten M. Gesing and Michael J. Vellekoop

Proceedings 2024, 97(1), 171; https://doi.org/10.3390/proceedings2024097171 - 9 Apr 2024

Viewed by 339

Abstract

Aerogels with noble metals have a wide range of applications such as sensing and catalysis, but research needs to be done to improve the integration of these materials in µ-channels. We realize silica aerogels without shrinkage and with high specific surface area (~600 [...] Read more.

Aerogels with noble metals have a wide range of applications such as sensing and catalysis, but research needs to be done to improve the integration of these materials in µ-channels. We realize silica aerogels without shrinkage and with high specific surface area (~600 m²/g) inside of closed channels. Further, Pt nanoparticles are deposited via capillary forces, into the complete network. Full article

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3 pages, 756 KiB

Open AccessAbstract

Smart Odour Sensing for Automated Monitoring of Bread Products

by Carmen Bax, Bianca di Diodoro, Alessandro Ticozzi, Nicolò Dellarosa, Flavio Corazza, Giacomo Langfelder and Laura Capelli

Proceedings 2024, 97(1), 172; https://doi.org/10.3390/proceedings2024097172 - 9 Apr 2024

Viewed by 306

Abstract

This work proposes an electronic nose (e-nose) system based on resistive gas sensors to predict the cooking evolution of different types of bread. The e-nose includes six metal-oxide semiconductor (MOS) gas sensors, a low-noise electronic system for signal conditioning and data acquisition, and [...] Read more.

This work proposes an electronic nose (e-nose) system based on resistive gas sensors to predict the cooking evolution of different types of bread. The e-nose includes six metal-oxide semiconductor (MOS) gas sensors, a low-noise electronic system for signal conditioning and data acquisition, and a classification algorithm for real-time detection of the cooking stage. Baking tests with five different recipes were carried out, and the system performances were evaluated by a panel of tasters, obtaining a -88% accuracy for the automatic detection of cooking time. Full article

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3 pages, 544 KiB

Open AccessAbstract

Portable Fluorescence Biosensing System for Low-Cost, Quantitative, and Multiplexed Allergen Screening

by Hui Chai-Gao, Yevhen Shynkarenko, Silvia Demuru, Nicola Hermann, Patricia-Daiana Boia, Peter Cristofolini, Bradley Petkus, Silvia Generelli, Stefano Cattaneo and Loïc Burr

Proceedings 2024, 97(1), 173; https://doi.org/10.3390/proceedings2024097173 - 10 Apr 2024

Viewed by 335

Abstract

A miniaturized multi-array system is being developed for immune-signature testing. The presented system includes microfluidic chips functionalized with allergens for IgE detection and a custom-made portable reader for fast (~1 s), quantitative, and sensitive (500 dye molecules/μm²) detection, with a high [...] Read more.

A miniaturized multi-array system is being developed for immune-signature testing. The presented system includes microfluidic chips functionalized with allergens for IgE detection and a custom-made portable reader for fast (~1 s), quantitative, and sensitive (500 dye molecules/μm²) detection, with a high spatial resolution (~50–100 μm). The developed solution enables the rapid sensing of allergic reactions at the point of care with a low-cost portable device. Full article

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3 pages, 658 KiB

Open AccessAbstract

Pull-In Voltage and Stress in Fixed-Fixed Beams of RF MEMS Switches

by Anna Persano, Girolamo Tagliapietra, Jacopo Iannacci, Alvise Bagolini, Fabio Quaranta and Pietro Siciliano

Proceedings 2024, 97(1), 174; https://doi.org/10.3390/proceedings2024097174 - 10 Apr 2024

Viewed by 314

Abstract

Electrostatically actuated microelectromechanical system (MEMS) switches with fixed- fixed beams were fabricated. FEM modeling was used to calculate the contributions of stress in the fabricated beams from the measured values of pull-in voltage. The reported study provides useful guidelines to optimize the design [...] Read more.

Electrostatically actuated microelectromechanical system (MEMS) switches with fixed- fixed beams were fabricated. FEM modeling was used to calculate the contributions of stress in the fabricated beams from the measured values of pull-in voltage. The reported study provides useful guidelines to optimize the design of fixed-fixed beams, in order to reduce the stress contributions for the successful development of efficient and reliable electrostatically actuated MEMS devices. Full article

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3 pages, 396 KiB

Open AccessAbstract

Microhotplate as a Platform for Calorimetry

by Rebeka Gy. Kiss, Lajos Harasztosi, István A. Szabó and Gábor Battistig

Proceedings 2024, 97(1), 175; https://doi.org/10.3390/proceedings2024097175 - 10 Apr 2024

Viewed by 304

Abstract

Calorimetry is a powerful method for characterising materials. The heat of a reaction can be directly measured with good accuracy. The established method usually requires large amounts of materials, which is a major drawback when studying thin film reactions. A MEMS microhotplate-based microcalorimeter [...] Read more.

Calorimetry is a powerful method for characterising materials. The heat of a reaction can be directly measured with good accuracy. The established method usually requires large amounts of materials, which is a major drawback when studying thin film reactions. A MEMS microhotplate-based microcalorimeter is developed in this study; it allows us to investigate thin film reactions by using a very small amount of materials. The temperature scale is calibrated by a well-known heat method of melting of two metal films. Energy calibration is also solved, and thus real information can be extracted for various solid-phase thin film reactions. In order to study reactions taking place close to room temperature, a cooled sample holder is developed, and the measurements can be started well below 0 °C. Full article

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3 pages, 505 KiB

Open AccessAbstract

Reliable Damping Simulation of Highly Perforated Micro-Electro-Mechanical Systems through Physical Compact Modeling

by Friederike Michael, Barbara Leikam and Gabriele Schrag

Proceedings 2024, 97(1), 176; https://doi.org/10.3390/proceedings2024097176 - 11 Apr 2024

Viewed by 309

Abstract

We present an approach to estimate damping in highly and irregularly perforated microplates over a wide range of pressures applying physics-based compact models implemented in a flux-conserving finite network. The models are coded in Verilog A, which allows for simulation using a standard [...] Read more.

We present an approach to estimate damping in highly and irregularly perforated microplates over a wide range of pressures applying physics-based compact models implemented in a flux-conserving finite network. The models are coded in Verilog A, which allows for simulation using a standard circuit simulator. This provides an efficient and customizable way to determine damping beyond the state of the art, and thus, to tailor and design the dynamic operation of MEMS in a predictive manner. Full article

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3 pages, 1261 KiB

Open AccessAbstract

Printed Anisotropic Magnetoresistive Sensors on Flexible Polymer Foils

by Clemens Voigt, Sindy Mosch, Eduardo Sergio Oliveros-Mata, Denys Makarov, Conrad Schubert, Morris Ott, Thomas Preußner and Mykola Vinnichenko

Proceedings 2024, 97(1), 177; https://doi.org/10.3390/proceedings2024097177 - 11 Apr 2024

Viewed by 314

Abstract

The experimental approach to the fabrication of flexible anisotropic magnetoresistive (AMR) sensors for magnetic field detection in the mT range is validated. It is based upon a combination of screen printing with high-power diode laser array post-processing, both of which are scalable and [...] Read more.

The experimental approach to the fabrication of flexible anisotropic magnetoresistive (AMR) sensors for magnetic field detection in the mT range is validated. It is based upon a combination of screen printing with high-power diode laser array post-processing, both of which are scalable and high-throughput methods. The whole process chain is evaluated, including powder preparation, paste formulation, screen printing, laser sintering, and characterization of microstructure and magnetoresistive response of the resulting sensors. Using high-quality permalloy powder with platelet geometry, the sensors with an AMR effect of 0.5–0.6% at 2–3 mT were realized on polymer substrates. The further optimization of the sensors’ preparation steps is in progress. Full article

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2 pages, 851 KiB

Open AccessAbstract

Prediction of Atmospheric Ozone Concentrations with a Temperature-Modulated Gas Sensor Array

by Arne Kobald, Udo Weimar and Nicolae Bârsan

Proceedings 2024, 97(1), 178; https://doi.org/10.3390/proceedings2024097178 - 11 Apr 2024

Viewed by 290

Abstract

Ozone is one of the most important pollutant gases. The excellent sensitivity and low limit of detection of gas sensors based on Semiconducting Metal Oxides (SMOXs) make them ideal candidates to accurately monitor outdoor air quality. We present a convolutional neural network (CNN) [...] Read more.

Ozone is one of the most important pollutant gases. The excellent sensitivity and low limit of detection of gas sensors based on Semiconducting Metal Oxides (SMOXs) make them ideal candidates to accurately monitor outdoor air quality. We present a convolutional neural network (CNN) architecture that is trained on the resistance readout of a multi-pixel SMOX gas sensor array operated in temperature modulation. The trained model outperforms a ridge regressor in the quantification of ozone concentrations in real outdoor air. Full article

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3 pages, 619 KiB

Open AccessAbstract

Real-Time Tracking of the Dynamic Viscosity of Bitumen with Piezoelectric MEMS Resonators

by Suresh Alasatri, Michael Schneider, Johannes Mirwald, Bernhard Hofko and Ulrich Schmid

Proceedings 2024, 97(1), 179; https://doi.org/10.3390/proceedings2024097179 - 12 Apr 2024

Viewed by 275

Abstract

This work demonstrates lab-scale monitoring of the dynamic viscosity of bitumen with piezoelectric MEMS resonators over a period of 120 h at an elevated temperature of 100 °C in air. The aluminium nitride-based MEMS resonator is excited in a high-order roof-tile-shaped mode to [...] Read more.

This work demonstrates lab-scale monitoring of the dynamic viscosity of bitumen with piezoelectric MEMS resonators over a period of 120 h at an elevated temperature of 100 °C in air. The aluminium nitride-based MEMS resonator is excited in a high-order roof-tile-shaped mode to provide high-quality factors while immersed in bitumen. The results demonstrate the robustness of the MEMS sensor, as it is capable of performing at elevated temperatures continuous measurements for a long time even in harsh environments like bitumen. Full article

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2 pages, 150 KiB

Open AccessAbstract

RFID Autonomous Sensors for Monitoring Corrosion on Prestressed Concrete Bridges

by Karim Bouzaffour, Philippe Talbot, Benoit Lescop, Stephane Rioual, Yannick Falaise, Cheikh Sarr, Sylvain Chataigner and Laurent Gaillet

Proceedings 2024, 97(1), 180; https://doi.org/10.3390/proceedings2024097180 - 12 Apr 2024

Viewed by 321

Abstract

Steel corrosion in concrete infrastructures is of worldwide interest. This paper reports the monitoring of concrete prestressed bridge infrastructures by autonomous sensors based on the RFID technology. Embedded autonomous sensors in concrete were produced for this purpose and tested in a laboratory environment. [...] Read more.

Steel corrosion in concrete infrastructures is of worldwide interest. This paper reports the monitoring of concrete prestressed bridge infrastructures by autonomous sensors based on the RFID technology. Embedded autonomous sensors in concrete were produced for this purpose and tested in a laboratory environment. Subsequent tests in real environments are in progress. Full article

3 pages, 644 KiB

Open AccessAbstract

Surface-Enhanced Raman Spectroscopy on Ag−WO₃/TiO₂ Inverse Opal Film Substrates

by Maria-Athina Apostolaki, Elias Sakellis, Polychronis Tsipas, Spiros Gardelis and Vlassis Likodimos

Proceedings 2024, 97(1), 181; https://doi.org/10.3390/proceedings2024097181 - 12 Apr 2024

Viewed by 352

Abstract

The synergetic effects of electromagnetic and chemical enhancements via the combination of semiconductor nanomaterials with noble metal nanoparticles is crucial to the performance of surface-enhanced Raman scattering (SERS). Here, WO₃/TiO₂ photonic crystal films in the form of three-dimensional inverse opals [...] Read more.

The synergetic effects of electromagnetic and chemical enhancements via the combination of semiconductor nanomaterials with noble metal nanoparticles is crucial to the performance of surface-enhanced Raman scattering (SERS). Here, WO₃/TiO₂ photonic crystal films in the form of three-dimensional inverse opals were fabricated via the co-assembly of polymer colloidal templates with water-soluble precursors in order to simultaneously grow both constituent metal oxides with tailored electronic properties and photonic band gaps. The surface modification of compositionally tuned WO₃/TiO₂ inverse opals by Ag nanoparticles is demonstrated to be an efficient method to boost SERS efficiency in the detection of 4−mercaptobenzoic acid via the synergy of plasmonic effects with charge transfer and slow-light trapping. Full article

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3 pages, 924 KiB

Open AccessAbstract

Small Footprint Temperature Sensing NFC Tag

by Jorge Pereira, Inês S. Garcia, Gabriel Ribeiro, José Fernandes, Filipe S. Alves, Marco Martins, André Cardoso and Rosana A. Dias

Proceedings 2024, 97(1), 182; https://doi.org/10.3390/proceedings2024097182 - 12 Apr 2024

Viewed by 319

Abstract

Smart NFC tags are seeing many interesting applications and can benefit from further miniaturization. A passive temperature sensing tag with 5.1 mm diameter is demonstrated, comprising a thin-film microfabricated antenna and an NFC chip. The microantenna/coil comprises two 15 µm-thick electroplated copper layers [...] Read more.

Smart NFC tags are seeing many interesting applications and can benefit from further miniaturization. A passive temperature sensing tag with 5.1 mm diameter is demonstrated, comprising a thin-film microfabricated antenna and an NFC chip. The microantenna/coil comprises two 15 µm-thick electroplated copper layers embedded in SU-8, withstanding the soldering process of a BGA NFC IC. The µ-antenna design challenge is to miniaturize while minimizing performance impairment (inductive-coupling distance), while the micromachining process is very dependent on topography propagation. Fabricated coils were successfully characterized (2.32 µH inductance; 13.76 MHz self-resonance) and temperature was read (after assembly) with a mobile phone at distances of up to 7 mm. Full article

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3 pages, 985 KiB

Open AccessAbstract

Capacitive Biosensor Based on a Peptide Hybrid Substrate for the Detection of MMP-13 in Chronic Wounds

by Amandine Sandoval, Brice Sorli, Arnaud Vena, Cécile Echalier, Ahmad Mehdi and Gilles Subra

Proceedings 2024, 97(1), 183; https://doi.org/10.3390/proceedings2024097183 - 12 Apr 2024

Viewed by 304

Abstract

This work focuses on a capacitive biosensor based on a hydride peptide for the detection of MMP-13. Indeed, the enzyme MMP-13 is a remarkable indicator of inflammation in chronic wounds. To achieve specific detection of this enzyme, a metallocene was added to the [...] Read more.

This work focuses on a capacitive biosensor based on a hydride peptide for the detection of MMP-13. Indeed, the enzyme MMP-13 is a remarkable indicator of inflammation in chronic wounds. To achieve specific detection of this enzyme, a metallocene was added to the peptide which amplifies the electrical variation allowing for proof of concept and reliability. Full article

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3 pages, 165 KiB

Open AccessAbstract

Optimizing Polyaniline-Based Gas Sensors for Hydrogen Sulfide Detection: The Crucial Role of Solvent Choice

by Maria L. Braunger, Edilene A. da Silva, Igor Fier, Nathalie Redon and Caroline Duc

Proceedings 2024, 97(1), 184; https://doi.org/10.3390/proceedings2024097184 - 12 Apr 2024

Viewed by 258

Abstract

Hydrogen sulfide (H₂S) gas poses a significant risk and thus demands continuous monitoring using reliable sensors. Chemiresistive sensors can serve this purpose, and the utilization of conducting polymeric materials, particularly polyaniline (PAni), has demonstrated significant potential. To fabricate chemiresistors based on [...] Read more.

Hydrogen sulfide (H₂S) gas poses a significant risk and thus demands continuous monitoring using reliable sensors. Chemiresistive sensors can serve this purpose, and the utilization of conducting polymeric materials, particularly polyaniline (PAni), has demonstrated significant potential. To fabricate chemiresistors based on PAni, the materials must be dispersed in an organic solvent like dimethylformamide (DMF), which has several hazardous properties. Fortunately, dimethyl sulfoxide (DMSO) is a safer alternative with similar properties to DMF, and may be used instead of DMF. In this study, we aim to compare the efficacy of DMF and DMSO solvents in fabricating PAni and metal chloride composite films for detecting H₂S gas. Full article

3 pages, 1754 KiB

Open AccessAbstract

Flexural Plate Wave Piezoelectric MEMS Pressure Sensor

by Alessandro Nastro, Stefano Bertelli, Marco Ferrari, Libor Rufer, Skandar Basrour and Vittorio Ferrari

Proceedings 2024, 97(1), 185; https://doi.org/10.3390/proceedings2024097185 - 15 Apr 2024

Viewed by 321

Abstract

A piezoelectric MEMS pressure sensor that exploits the first antisymmetric vibration mode (A0) of Lamb waves is presented. The 6 mm × 6 mm diaphragm used to sense the applied pressure is composed of a stack of doped silicon (Si) and aluminum nitride [...] Read more.

A piezoelectric MEMS pressure sensor that exploits the first antisymmetric vibration mode (A0) of Lamb waves is presented. The 6 mm × 6 mm diaphragm used to sense the applied pressure is composed of a stack of doped silicon (Si) and aluminum nitride (AlN) layers with metal interdigital transducers (IDTs) to generate flexural plate waves (FPWs). The working principle has been validated through 2D finite element analysis within the frequency range 10–15 MHz and experimentally verified. A variable pressure has been applied across the diaphragm while measuring the electrical admittance of a single IDT. Experimental data are in good agreement with simulations showing a frequency shift of the admittance peaks when pressure acts on the MEMS diaphragm. For an applied pressure of 170 Pa, a relative frequency variation of 0.25% has been achieved. Full article

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3 pages, 921 KiB

Open AccessAbstract

Triboelectric Energy Harvesting Shoe Insole

by Zifan Li, Lihua Tang, Wee Chen Gan and Kean Chin Aw

Proceedings 2024, 97(1), 186; https://doi.org/10.3390/proceedings2024097186 - 15 Apr 2024

Viewed by 333

Abstract

Harvesting power from walking-related motions can be a sustainable energy source for powering wearables. This paper proposes a shoe insole with a 3D stackable self-supporting structure and energy harvesting capability based on triboelectrification. Initial tests showed that a unit cell of the structure [...] Read more.

Harvesting power from walking-related motions can be a sustainable energy source for powering wearables. This paper proposes a shoe insole with a 3D stackable self-supporting structure and energy harvesting capability based on triboelectrification. Initial tests showed that a unit cell of the structure could produce an open-circuit voltage of 164.5 V with a charge density of 2.02 nC/cm², and the performance can be further improved with a higher force and a structure of multiple cells. Full article

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3 pages, 461 KiB

Open AccessAbstract

Microfluidic System with Integrated Electrode Array for High-Throughput Electrochemical Impedance Spectroscopy Analysis of Localised Cells

by Lilia Bató and Péter Fürjes

Proceedings 2024, 97(1), 187; https://doi.org/10.3390/proceedings2024097187 - 16 Apr 2024

Viewed by 258

Abstract

A multi-channel microfluidic system was designed and fabricated with an integrated electrode array to be capable of trapping and analysing single cells or populations in the individual channels in a controlled chemical environment. The analytical system was interfaced with a dedicated printed circuit [...] Read more.

A multi-channel microfluidic system was designed and fabricated with an integrated electrode array to be capable of trapping and analysing single cells or populations in the individual channels in a controlled chemical environment. The analytical system was interfaced with a dedicated printed circuit board designed for parallel EIS and optical screening. The continuous impedance measurement also monitors the adequate filling of the channels and the cell trapping events. Yeast cells were characterised by recording the EIS spectra of individual channels, allowing the differentiation between the populations considering their size, viability, or proliferation. The EIS analysis was supported by fluorescent optical microscopy, also using cell staining. Full article

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2 pages, 458 KiB

Open AccessAbstract

Wearable Prototype for Smart Personal Protective Equipment

by Fabrizio Formisano, Antonio Del Giudice, Michele Dellutri and Girolamo Di Francia

Proceedings 2024, 97(1), 188; https://doi.org/10.3390/proceedings2024097188 - 16 Apr 2024

Viewed by 285

Abstract

Smart personal protective equipment (PPE) broadens the ways to enhance security in workplaces. Using active systems with communication capabilities, it is possible to continuously monitor workers and environmental parameters to prevent undesirable events or to quickly intervene in case of accident. This work [...] Read more.

Smart personal protective equipment (PPE) broadens the ways to enhance security in workplaces. Using active systems with communication capabilities, it is possible to continuously monitor workers and environmental parameters to prevent undesirable events or to quickly intervene in case of accident. This work describes the latest improvements in the design of an upgraded version of our earlier laboratory prototype. The enhancements concern a more compact form factor, reduced power consumption and replacements with the latest products available on the market. In this work, the design solution and results will be presented. Full article

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3 pages, 872 KiB

Open AccessAbstract

Controlled Contact between Beads and Cells for the Characterization of Receptor–Ligand Bonds

by Clémentine Lipp, Laure Koebel, Romain Loyon, Aude Bolopion, Laurie Spehner, Michaël Gauthier, Christophe Borg, Arnaud Bertsch and Philippe Renaud

Proceedings 2024, 97(1), 189; https://doi.org/10.3390/proceedings2024097189 - 16 Apr 2024

Viewed by 283

Abstract

The controlled contact between two micro-sized objects, such as beads and cells, and the assessment of their adhesion status is demonstrated in this research. The controlled contact is carried out in a microfluidic channel under flow conditions and makes use of a combination [...] Read more.

The controlled contact between two micro-sized objects, such as beads and cells, and the assessment of their adhesion status is demonstrated in this research. The controlled contact is carried out in a microfluidic channel under flow conditions and makes use of a combination of hydrodynamic traps, flow drag force and dielectrophoretic (DEP) force to maintain the two objects in contact for the desired duration in a first step. Then, the pair objects are separated in the second step in order to explore their adhesion status. Adhesion events are mediated by the bond formed between a receptor and its ligand, and their binding kinetic parameters can be extracted from the measurements using the proposed device. Full article

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3 pages, 1155 KiB

Open AccessAbstract

Two-Dimensional Layered Amorphous Metal Oxide Gas Sensors (LAMOS) Perspectives and Gas Sensing Properties

by Valentina Paolucci, Jessica De Santis, Vittorio Ricci, Giacomo Giorgi and Carlo Cantalini

Proceedings 2024, 97(1), 190; https://doi.org/10.3390/proceedings2024097190 - 17 Apr 2024

Viewed by 291

Abstract

Two-dimensional Layered Amorphous Metal Oxide Sensors (LAMOS) represent a new class of 2D amorphous oxide (a-MOx) interfaces with unveiled properties in gas sensing applications. Herein, we report the humidity and gas sensing response of p- and n-type chemoresistive few-layered [...] Read more.

Two-dimensional Layered Amorphous Metal Oxide Sensors (LAMOS) represent a new class of 2D amorphous oxide (a-MOx) interfaces with unveiled properties in gas sensing applications. Herein, we report the humidity and gas sensing response of p- and n-type chemoresistive few-layered (2D) amorphous a-SnO₂, a-In₂O₃, and a-Cr₂O₃, discussing their reaction mechanisms using DFT modelling and electrical tests. LAMOS interfaces can be easily prepared by controlled oxidation in air of a large class of exfoliated 2D TMDs, MCs, and TMTH (Transition Metal Dichalcogenides, Chalcogenides, and Trihalides) like WS₂, MoS₂, SnSe₂, In₂Se₃, NiCl₂, and CrCl₃, yielding 2D amorphous a-MOx interfaces. LAMOS platforms preserving all the surface-to-volume advantages of their 2D precursors show excellent gas sensing properties representing a new class of material for gas sensing applications. Full article

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3 pages, 403 KiB

Open AccessAbstract

Optimization of Micro-Electromechanical Lorentz Actuator Using a Surrogate Model Accelerated Genetic Algorithm

by Phiona Buhr, Cyrus Shafai, Byoungyoul Park, Yunli Wang and Miroslav Belov

Proceedings 2024, 97(1), 191; https://doi.org/10.3390/proceedings2024097191 - 17 Apr 2024

Viewed by 281

Abstract

A surrogate model (SM)-assisted multi-objective genetic algorithm (GA) is presented that is used to accelerate the performance optimization of a MEMS actuator. The GA employs both finite element method (FEM) simulations and the SM together to undertake the multi-objective optimization. The algorithm evolves [...] Read more.

A surrogate model (SM)-assisted multi-objective genetic algorithm (GA) is presented that is used to accelerate the performance optimization of a MEMS actuator. The GA employs both finite element method (FEM) simulations and the SM together to undertake the multi-objective optimization. The algorithm evolves the actuator geometry to meet a required 1 µm displacement while seeking to achieve the objectives of minimal temperature rise and resonant frequency over 5 kHz. The result is a continuous surface of Pareto optimal designs for the decision maker to choose from. The SM was found to compute similar solutions as the FEM with a 100,000× faster computation speed. Full article

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3 pages, 1024 KiB

Open AccessAbstract

Silver-Based Plasmonic Grating with PDMS Microchannel for Biological Sensors

by Pongsak Sarapukdee, Dirk Schulz and Stefan Palzer

Proceedings 2024, 97(1), 192; https://doi.org/10.3390/proceedings2024097192 - 17 Apr 2024

Viewed by 234

Abstract

The label-free approach streamlines sample analysis by eliminating the need for fluorescent markers or labels, thus improving accuracy and speed. This contribution explores the potential of silver-based plasmonic gratings as central building blocks for developing biological sensors using label-free detection techniques. It presents [...] Read more.

The label-free approach streamlines sample analysis by eliminating the need for fluorescent markers or labels, thus improving accuracy and speed. This contribution explores the potential of silver-based plasmonic gratings as central building blocks for developing biological sensors using label-free detection techniques. It presents the design, fabrication, and optimization of plasmonic gratings, including showcasing their application in biological molecule detection. Full article

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3 pages, 461 KiB

Open AccessAbstract

Non-Stoichiometric Titanium-Oxide Gate Electrodes for EGFET Based pH Sensors

by Zsombor Szomor, Lilia Bató, Silvia Stágl, Orsolya Hakkel, Attila Sulyok, Csaba Dücső, Zsófia Baji and Péter Fürjes

Proceedings 2024, 97(1), 193; https://doi.org/10.3390/proceedings2024097193 - 17 Apr 2024

Viewed by 268

Abstract

A compact pH measuring electrochemical sensor module was developed for Smart Multi-Well Plates (SMWP) applicable for highly parallelized cell culture analysis using incorporated Organ-on-Chip devices. A specific electronic architecture was designed and manufactured containing an extended gate field effect transistor as the transducer [...] Read more.

A compact pH measuring electrochemical sensor module was developed for Smart Multi-Well Plates (SMWP) applicable for highly parallelized cell culture analysis using incorporated Organ-on-Chip devices. A specific electronic architecture was designed and manufactured containing an extended gate field effect transistor as the transducer device. Electrochemical electrodes were functionalized using pH sensitive metal-oxides and applied as the gate material. The composition and the related pH sensitivity of differently deposited materials were characterized and the suitability of ALD-deposited, non-stoichiometric titanium oxide (TiO_x) for sensitive pH measurement was verified showing excellent responses close to the ideal Nernstian slope (59 mV/pH). Full article

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3 pages, 770 KiB

Open AccessAbstract

Multianalyte-Compatible Lysis for the Detection of P. aeruginosa and IL-6 via Lateral Flow Immunoassay

by Anna Klebes, Bianka Pfefferle, Anna-Sophia Kittel, Bastian Breiner, Nadine Borst and Felix von Stetten

Proceedings 2024, 97(1), 194; https://doi.org/10.3390/proceedings2024097194 - 17 Apr 2024

Viewed by 307

Abstract

The development of new multianalyte biosensors that can detect multiple classes of biomolecules is highly desirable and will greatly improve medical diagnostics. In the field of infectious diseases, for example, it is beneficial to detect pathogens via nucleic acid analysis together with host [...] Read more.

The development of new multianalyte biosensors that can detect multiple classes of biomolecules is highly desirable and will greatly improve medical diagnostics. In the field of infectious diseases, for example, it is beneficial to detect pathogens via nucleic acid analysis together with host immune response markers. In this work, we present a multianalyte-compatible lysis using antimicrobial peptides (AMPs). This strategy enables the simultaneous detection of bacterial DNA and inflammatory biomarkers via multianalyte lateral flow immunoassay (LFIA). Full article

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3 pages, 464 KiB

Open AccessAbstract

Soft Optomechanical Devices Featuring Intrinsic Redox Activity

by Ferran Pujol-Vila and Mar Álvarez

Proceedings 2024, 97(1), 195; https://doi.org/10.3390/proceedings2024097195 - 19 Apr 2024

Viewed by 276

Abstract

Soft optomechanical sensors have the ability to combine the high tunability and elasticity of soft polymers with the distinctive optical properties of photonic structures, thus offering unprecedented opportunities for the development high-performance colorimetric sensors. Herein, we demonstrate for the first time the use [...] Read more.

Soft optomechanical sensors have the ability to combine the high tunability and elasticity of soft polymers with the distinctive optical properties of photonic structures, thus offering unprecedented opportunities for the development high-performance colorimetric sensors. Herein, we demonstrate for the first time the use of optomechanical devices made of off-stoichiometry thiol-ene (OSTE), a polymeric material that features intrinsic redox activity, overcoming some limitations of conventional materials (e.g., polydimethylsiloxane or silicon). Remarkably, this work provides the foundation for a new generation of highly tunable and versatile optomechanical sensors, enabling unexplored functionalities. Full article

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2 pages, 660 KiB

Open AccessAbstract

Merging Surface Plasmon Optical Detection with Electronic Sensing

by Wolfgang Knoll

Proceedings 2024, 97(1), 196; https://doi.org/10.3390/proceedings2024097196 - 19 Apr 2024

Viewed by 240

Abstract

In one of the “classical” configurations of electrolyte-gated field effect transistors (EGOFETs) for biosensing, the planar gate electrode is functionalized by (a monolayer of) receptors, to which the analyte molecules of interest bind from the analyte solution, thereby modifying the gate potential, which [...] Read more.

In one of the “classical” configurations of electrolyte-gated field effect transistors (EGOFETs) for biosensing, the planar gate electrode is functionalized by (a monolayer of) receptors, to which the analyte molecules of interest bind from the analyte solution, thereby modifying the gate potential, which in turn modifies the source drain current as the sensor output signal [...] Full article

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2 pages, 632 KiB

Open AccessAbstract

Recent Improvements on Double-Parametric Optical Sensing of O₂ Exploiting Near-Infrared Luminescence of Mixed-Phase Anatase/Rutile TiO₂ Nanoparticles

by Romina Rega, Ambra Fioravanti, Pietro Marani, Sara Morandi, Laura Giordano, Stefano Lettieri, Maria Cristina Carotta and Pasquale Maddalena

Proceedings 2024, 97(1), 197; https://doi.org/10.3390/proceedings2024097197 - 19 Apr 2024

Viewed by 270

Abstract

Mixed-phase titanium dioxide (TiO₂) can be effectively employed as photoluminescence (PL) based ratiometric optical sensor of O₂, thanks to its peculiar “anti-correlated” PL responses to O₂ of anatase and rutile TiO₂ polymorphs. We discuss how to exploit [...] Read more.

Mixed-phase titanium dioxide (TiO₂) can be effectively employed as photoluminescence (PL) based ratiometric optical sensor of O₂, thanks to its peculiar “anti-correlated” PL responses to O₂ of anatase and rutile TiO₂ polymorphs. We discuss how to exploit the simultaneous detection of luminescence arising from anatase and rutile TiO₂ nanoparticles to obtain a responsivity which is, by construction, larger than the one obtainable through other gas-responsive oxides via the same PL-based approach. Furthermore, we illustrate our recent improvements on sensor sensitivity and stability for O₂ concentrations ranging in the 10–100 ppm interval. Full article

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3 pages, 946 KiB

Open AccessAbstract

AMR Sensor Array Design for the Realization of a 3D Magnetic Tactile Sensor

by Stefano Lumetti, Perla Malagò, Peter-Andreas Stürmer, Francisco Ferreira Relvão and Michael Ortner

Proceedings 2024, 97(1), 198; https://doi.org/10.3390/proceedings2024097198 - 22 Apr 2024

Viewed by 248

Abstract

The design of arrays of anisotropic magnetoresistive (AMR) sensors capable of detecting and reconstructing the 3D motion of a permanent magnet, and thus, suitable for the development of a 3D magnetic tactile sensor, is reported. The proposed structure allows for probing the 3D [...] Read more.

The design of arrays of anisotropic magnetoresistive (AMR) sensors capable of detecting and reconstructing the 3D motion of a permanent magnet, and thus, suitable for the development of a 3D magnetic tactile sensor, is reported. The proposed structure allows for probing the 3D magnet displacements—and, hence, to infer the three components of the applied force—via a purely planar arrangement of monolithically microfabricated AMR sensors. The concept presented here also holds potential for the realization of a wide spectrum of easy-to-fabricate, miniaturized and low-cost sensors suitable for the detection of a broad variety of physical observables. Full article

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3 pages, 427 KiB

Open AccessAbstract

Automated Allergen Sample Preparation and Detection via Centrifugal Microfluidic Lateral Flow Assay

by Bastian Breiner, Daniel M. Kainz, Stefan Wagner, Maxime Gavage, Serhat Sahakalkan, Riccardo Marega, Felix von Stetten and Anna Klebes

Proceedings 2024, 97(1), 199; https://doi.org/10.3390/proceedings2024097199 - 22 Apr 2024

Viewed by 285

Abstract

Food allergies are a severe burden for affected individuals and healthcare systems. To tackle the need for simple food allergen detection, we developed a system for the detection of the soy protein glycinin via a centrifugal microfluidics-assisted lateral flow immunoassay (LFIA). Glycinin is [...] Read more.

Food allergies are a severe burden for affected individuals and healthcare systems. To tackle the need for simple food allergen detection, we developed a system for the detection of the soy protein glycinin via a centrifugal microfluidics-assisted lateral flow immunoassay (LFIA). Glycinin is a complex allergen requiring extensive sample preparation. The presented workflow includes a manual denaturing extraction, followed by automated centrifugal microfluidic desalting, metering and detection via LFIA. The functionality of the microfluidic cassettes was tested on prototypes produced via microthermoforming before an injection molding tool was designed, which added a cylindrical lens to improve the readout. Overall, this system aims to aid in food allergen detection with high sensitivity and minimized manual steps. Full article

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3 pages, 725 KiB

Open AccessAbstract

A Hybrid Piezoelectric and Reverse Electrowetting Energy Harvester for Wearable Biosensors

by Sotiria D. Psoma, Ihor Sobianin and Antonios Tourlidakis

Proceedings 2024, 97(1), 200; https://doi.org/10.3390/proceedings2024097200 - 23 Apr 2024

Viewed by 238

Abstract

Wearable biosensors play a critical role in healthcare monitoring. However, the reliance of biosensors on batteries has serious drawbacks. Although the human body’s energy can be converted into electricity with energy harvesters, the hybridisation of multiple energy harvesters is a prominent way of [...] Read more.

Wearable biosensors play a critical role in healthcare monitoring. However, the reliance of biosensors on batteries has serious drawbacks. Although the human body’s energy can be converted into electricity with energy harvesters, the hybridisation of multiple energy harvesters is a prominent way of increasing power output. In this work, a hybrid piezoelectric and reverse electrowetting (REWOD) energy harvester is proposed. Its main working principle is based on the presence of an electrical double layer in the REWOD component and coupling with a piezoelectric nanogenerator via an electret. The proposed energy harvester design was tested numerically and in a series of experiments. Full article

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3 pages, 2200 KiB

Open AccessAbstract

A Flexible PCB-Based MEMS Field Mill with a Vertical Movement Shutter Driven by an Electrostatic Actuator

by Tao Chen and Cyrus Shafai

Proceedings 2024, 97(1), 201; https://doi.org/10.3390/proceedings2024097201 - 23 Apr 2024

Viewed by 219

Abstract

This paper describes a simulated MEMS field mill that utilizes a vertical movement shutter powered by an electrostatic actuator. The design is based upon a Flexible PCB substrate to enable faster prototyping and lower cost. The simulation results show that if the system [...] Read more.

This paper describes a simulated MEMS field mill that utilizes a vertical movement shutter powered by an electrostatic actuator. The design is based upon a Flexible PCB substrate to enable faster prototyping and lower cost. The simulation results show that if the system operates at a resonance, a 10 kV/m field will induce a current of 53 pA, resulting in a charge induction efficiency of 5.3 pA/(kV/m). Full article

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3 pages, 1258 KiB

Open AccessAbstract

A Simple Method for Extracting Piezoelectric Coefficient d₃₁ by Fitting Experimental Data with an Analytical Model

by Yangyang Guan, Mustafa Mert Torunbalci, Sanjog Vilas Joshi, Sina Sadeghpour, Aojie Quan, Chen Wang and Michael Kraft

Proceedings 2024, 97(1), 202; https://doi.org/10.3390/proceedings2024097202 - 16 Apr 2024

Viewed by 164

Abstract

This work presents a simple method to extract the piezoelectric coefficient

d_{31}

based on analytical model fitting. A theoretical circuit model is developed for a piezoelectric circular membrane actuator based on PZT thin film. The circular diaphragm consists of a 12 µm [...] Read more.

This work presents a simple method to extract the piezoelectric coefficient

d_{31}

based on analytical model fitting. A theoretical circuit model is developed for a piezoelectric circular membrane actuator based on PZT thin film. The circular diaphragm consists of a 12 µm silicon layer, an 800 nm thick PZT layer, and a 200 nm Ti/Pt layer, featuring a single 50% inner top electrode coverage. The proposed model is validated by the finite element method with a 2D axisymmetric model of a PZT piezoelectric membrane. Further, piezoelectric coefficient

d_{31}

is extracted by fitting the Laser Doppler Vibrometer (LDV) experimental result with the analytical model. Full article

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5 pages, 2715 KiB

Open AccessAbstract

Systematic Review on Biosensor Systems for COVID-19 Aerosol Detection

by Divya Pragna Mulla, Mario Alessandro Bochicchio and Antonella Longo

Proceedings 2024, 97(1), 203; https://doi.org/10.3390/proceedings2024097203 - 24 Apr 2024

Viewed by 290

Abstract

Timely detection and diagnosis are crucial for outbreak measures and infection control. This review discusses the types of biosensor systems developed so far for the detection of COVID-19 aerosols in the air for the risk assessment and identification of gaps in the field. [...] Read more.

Timely detection and diagnosis are crucial for outbreak measures and infection control. This review discusses the types of biosensor systems developed so far for the detection of COVID-19 aerosols in the air for the risk assessment and identification of gaps in the field. Data were collected from four academic databases, including IEEE Xplore, Scopus, Web of Science, and MDPI. The results suggest the development of very few sensors for the aerosol detection of COVID-19, and most of the sensors are immune based. Full article

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3 pages, 474 KiB

Open AccessAbstract

Graphene Oxide-Based Flexible Sensors for Detection of Volatile Organic Compounds at Room Temperature

by Anna Maria Laera, Gennaro Cassano, Emiliano Burresi, Maria Lucia Protopapa and Michele Penza

Proceedings 2024, 97(1), 204; https://doi.org/10.3390/proceedings2024097204 - 24 Apr 2024

Viewed by 249

Abstract

Flexible sensors, with an active layer made of graphene oxide (GO), were produced to detect volatile organic compounds (VOCs) at room temperature. Copper interdigitated electrodes were inkjet-printed on a substrate of bimatted polyester, and the direct drop-casting of a GO water solution was [...] Read more.

Flexible sensors, with an active layer made of graphene oxide (GO), were produced to detect volatile organic compounds (VOCs) at room temperature. Copper interdigitated electrodes were inkjet-printed on a substrate of bimatted polyester, and the direct drop-casting of a GO water solution was carried out to coat the devices. The performance of both commercial GO and GO synthesized by a modified Hummers’ method was investigated and compared. The oxygenated functional groups on the GO surface mainly enhance the selective sensing of polar analytes. The fabricated sensors exhibit the highest response towards alcohols, and minor sensitivity to esters, ketones, ethers and apolar petroleum ether. Full article

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2 pages, 348 KiB

Open AccessAbstract

A New Active Antenna Unit for Portable Microwave Bio-Dosimeters

by Andrey Simakov, Igor Vodokhlebov and Yuriy Voronov

Proceedings 2024, 97(1), 205; https://doi.org/10.3390/proceedings2024097205 - 24 Apr 2024

Viewed by 237

Abstract

Today, the growing ecological contamination by microwave irradiation requires new devices and information systems to monitor dangerous situations, especially in big cities, and provide safety for the population. This work is focused on the design of anew antenna unit for advanced portable personal [...] Read more.

Today, the growing ecological contamination by microwave irradiation requires new devices and information systems to monitor dangerous situations, especially in big cities, and provide safety for the population. This work is focused on the design of anew antenna unit for advanced portable personal microwave dosimeters and irradiation monitoring systems. Full article

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3 pages, 420 KiB

Open AccessAbstract

Noble Metal-Loaded WO₃-Based Gases—The Gold Anomaly

by Anna Staerz, Udo Weimar and Nicolae Barsan

Proceedings 2024, 97(1), 206; https://doi.org/10.3390/proceedings2024097206 - 24 Apr 2024

Viewed by 240

Abstract

Tungsten oxide is one of the most commonly used materials for metal oxide-based gas sensors. In order to tune the sensing behavior, small clusters of noble metals are often added to the surface of WO₃. Previously, it has been found that [...] Read more.

Tungsten oxide is one of the most commonly used materials for metal oxide-based gas sensors. In order to tune the sensing behavior, small clusters of noble metals are often added to the surface of WO₃. Previously, it has been found that in the case of oxidized metal clusters, e.g., Rh and Pt additives, the Fermi-level pinning mechanism dominates. Unlike other noble metal surface clusters, gold seems to remain metallic under sensor operation. As a result, the behavior of WO₃-based sensors was found to be significantly enhanced for all reducing gases and decreased for NO₂. Full article

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3 pages, 388 KiB

Open AccessAbstract

Isotope-Selective Gas Sensing Using Photoacoustic Non-Dispersive Spectroscopy

by Gabriel Rodriguez Gutierrez, Loay Marouani, Alvaro Ortiz Perez, Peter Kreuzaler and Stefan Palzer

Proceedings 2024, 97(1), 207; https://doi.org/10.3390/proceedings2024097207 - 24 Apr 2024

Viewed by 204

Abstract

The flow of carbons into the citric acid cycle can be readily traced by supplementation with ¹³C stable isotope labelled nutrients. However, the quantification of the amount of fully oxidised nutrients to carbon dioxide is a challenging task. This contribution presents an [...] Read more.

The flow of carbons into the citric acid cycle can be readily traced by supplementation with ¹³C stable isotope labelled nutrients. However, the quantification of the amount of fully oxidised nutrients to carbon dioxide is a challenging task. This contribution presents an isotope-selective, miniaturized gas detection scheme based on indirect photoacoustic spectroscopy. The results show that low-cost, continuous, in situ monitoring of the isotope ratio in gaseous samples is feasible. Full article

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3 pages, 1567 KiB

Open AccessAbstract

Sample Preparation and qPCR Detection of Tuberculosis on a Centrifugal Microfluidic Cartridge Enabling Molecular Downstream Resistance Profiling

by Judith Schlanderer, Markus Beutler, Jan Lüddecke, Harald Hoffmann and Nils Paust

Proceedings 2024, 97(1), 208; https://doi.org/10.3390/proceedings2024097208 - 26 Apr 2024

Viewed by 266

Abstract

Tuberculosis (TB) is still one of the world’s deadliest infections. Fast detection of the pathogen M. tuberculosis (MTB) and its genetic resistance markers substantially improves treatment success and outcome. A key element for rapid genetic diagnostics is the efficient extraction of DNA from [...] Read more.

Tuberculosis (TB) is still one of the world’s deadliest infections. Fast detection of the pathogen M. tuberculosis (MTB) and its genetic resistance markers substantially improves treatment success and outcome. A key element for rapid genetic diagnostics is the efficient extraction of DNA from sputum for qPCR detection at the point of care. We present the fully automated sample preparation of MTB DNA from 3 mL of liquefied sputum and qPCR detection of MTB on a centrifugal microfluidic cartridge. Our method achieves a limit of detection (LoD) between 17 and 57 CFU/mL and provides a purified DNA solution for molecular downstream testing, such as targeted NGS. Full article

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3 pages, 525 KiB

Open AccessAbstract

Microfluidic Cuvette for Near-Infrared Spectroscopy

by Zoltán Szabó, Kitti Pankász, János Bozorádi, Orsolya Hakkel, Szabolcs Bella, Bianka Fabinyi, Sandro Meucci and Péter Fürjes

Proceedings 2024, 97(1), 209; https://doi.org/10.3390/proceedings2024097209 - 6 May 2024

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Abstract

We intend to develop an in situ near-infrared spectroscopic solution for monitoring the nutrient composition (e.g., lactate concentration) in microfluidic channels of organ-on-chip devices. In this work, the effects of the geometry, surface quality, and architecture of the micro-volume cuvettes were characterized and [...] Read more.

We intend to develop an in situ near-infrared spectroscopic solution for monitoring the nutrient composition (e.g., lactate concentration) in microfluidic channels of organ-on-chip devices. In this work, the effects of the geometry, surface quality, and architecture of the micro-volume cuvettes were characterized and optimized considering the signal-to-noise ratio and sensitivity of the proposed spectroscopic method in case of aqueous solutions. The applicability of the micro-volume near-infrared spectroscopy method using this specially designed microfluidic cuvette was proven. Full article

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4 pages, 1316 KiB

Open AccessAbstract

Numerically Stable Magnetic Field Expressions for End-of-Shaft Angle Sensing Systems

by Peter Leitner, Lukas Rauber and Michael Ortner

Proceedings 2024, 97(1), 210; https://doi.org/10.3390/proceedings2024097210 - 6 May 2024

Viewed by 116

Abstract

The design of end-of-shaft angle sensing magnetic positioning systems (MPS) requires accurate field computations in the sensing area for the magnetostatic inversion procedure. Highly resolved field computations on a 3-D domain make FEM simulations unfeasible and favour analytical solutions. Analytical textbook field solutions [...] Read more.

The design of end-of-shaft angle sensing magnetic positioning systems (MPS) requires accurate field computations in the sensing area for the magnetostatic inversion procedure. Highly resolved field computations on a 3-D domain make FEM simulations unfeasible and favour analytical solutions. Analytical textbook field solutions of a number of standard magnet shapes are however numerically unstable along symmetry axes, body edges as well as in the far field. For the particular application of an end-of-shaft system, only a particular instability close to the symmetry axis, ρ → 0 plays a detrimental role. We stabilize the field equation by mathematical reformulation of naturally occurring numerically unstable combinations of elliptic integrals in the derivation. The resulting formulas or even their ready-to-use implementation in the freely available Python package Magpylib can be used without limitations for end-of-shaft MPS designs. Full article

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3 pages, 534 KiB

Open AccessAbstract

Pulsed Temperature Operation of SnO₂-Based Gas Sensors

by Larissa Egger, Lisbeth Reiner, Alessandro Togni, Christian Mitterer and Anton Köck

Proceedings 2024, 97(1), 211; https://doi.org/10.3390/proceedings2024097211 - 6 May 2024

Viewed by 114

Abstract

We herein demonstrate the pulsed-mode temperature operation of chemical sensor devices based on thin SnO₂ films, which were synthesized by magnetron sputtering. The gas-sensitive films were integrated on SiN-based micro-hotplate (µhp) chips, which enable operation temperatures up to 500 °C. We compared [...] Read more.

We herein demonstrate the pulsed-mode temperature operation of chemical sensor devices based on thin SnO₂ films, which were synthesized by magnetron sputtering. The gas-sensitive films were integrated on SiN-based micro-hotplate (µhp) chips, which enable operation temperatures up to 500 °C. We compared the gas sensor performance in constant temperature mode with pulsed temperature mode operation towards the test gases carbon monoxide and toluene. In contrast to constant temperature, the pulsed temperature mode operation reveals additional information about the type of test gas. Full article

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3 pages, 411 KiB

Open AccessAbstract

Electrochemical Analysis of Rationally Designed ZnO Nanostructures for Biodegradable Cellular Scaffolds

by Giuseppe Arrabito, Vittorio Ferrara, Giuseppe Prestopino, Pier Gianni Medaglia, Michelangelo Scopelliti and Bruno Pignataro

Proceedings 2024, 97(1), 212; https://doi.org/10.3390/proceedings2024097212 - 6 May 2024

Viewed by 61

Abstract

This work is a preliminary analysis of a wet-chemistry synthesized platform based on ZnO nanostructures (n-ZnO) for application in regenerative medicine. n-ZnO stability is investigated by electrochemical in situ sensing of zinc ions released by n-ZnO soaked in simulated biofluids. Impedance analysis allows [...] Read more.

This work is a preliminary analysis of a wet-chemistry synthesized platform based on ZnO nanostructures (n-ZnO) for application in regenerative medicine. n-ZnO stability is investigated by electrochemical in situ sensing of zinc ions released by n-ZnO soaked in simulated biofluids. Impedance analysis allows detection of subtle changes in the bulk solution impedance up to 50 kHz, which can be ascribed to the release of ionic species in solution, among which are Zn²⁺ ions. In parallel, a voltammetry analysis using low-cost, mercury-free, screen-printed sensors shows the release of Zn²⁺ ions at concentrations that are not harmful. Full article

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3 pages, 674 KiB

Open AccessAbstract

Analysis and Development of Rotational Angle Sensor

by Yu-Wen Chen and Cheng-Yao Lo

Proceedings 2024, 97(1), 7025; https://doi.org/10.3390/proceedings2024097025 - 15 Mar 2024

Viewed by 349

Abstract

This research focuses on the rotational angle acquisition of a flexible sensor. A numerical analysis is conducted during design to discuss the sensor’s capacitance changes under rotation. A working range from −4° to 4° is investigated and fittings are predicted. Furthermore, manufacturing processes [...] Read more.

This research focuses on the rotational angle acquisition of a flexible sensor. A numerical analysis is conducted during design to discuss the sensor’s capacitance changes under rotation. A working range from −4° to 4° is investigated and fittings are predicted. Furthermore, manufacturing processes are used to realize the electrode, mold and spacers. After that, the sensor is measured to determine its capacitance signal. Full article

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9 pages, 3295 KiB

Open AccessProceeding Paper

Design and Demonstration of Radio Frequency Micro Electro-Mechanical System Switches with Meandered Beams for Reduced Actuation Voltage

by Girolamo Tagliapietra, Jacopo Iannacci, Flavio Giacomozzi and Leandro Lorenzelli

Proceedings 2024, 97(1), 17; https://doi.org/10.3390/proceedings2024097017 - 14 Mar 2024

Viewed by 367

Abstract

In this paper, a class of three series ohmic switches is presented, including its design principles, the simulation results, and the outcomes of the measurements performed on the first batch of fabricated samples. The design of the adopted membranes is based on meandered [...] Read more.

In this paper, a class of three series ohmic switches is presented, including its design principles, the simulation results, and the outcomes of the measurements performed on the first batch of fabricated samples. The design of the adopted membranes is based on meandered beams, targeting a reduced actuation voltage. The initial and promising electro-mechanical simulations, performed in an Ansys Workbench environment, predicted actuation voltages in the 5–8 V range, whereas the measurements highlighted slightly greater values. The electro-magnetic behavior of such devices demonstrated a general and qualitative agreement with the simulations performed in the Ansys HFSS environment, with a satisfying performance in terms of return loss (<−20.22 dB) and isolation (<−14.86 dB) along the 5–30 GHz interval. Full article

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