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Proceedings, 2024, Eurosensors 2023

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3 pages, 687 KiB  
Abstract
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 351
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  
Abstract
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 345
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  
Abstract
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 382
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  
Abstract
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 325
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  
Abstract
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 414
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  
Abstract
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 365
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  
Abstract
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 604
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  
Abstract
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 339
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  
Abstract
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 378
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  
Abstract
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 298
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  
Abstract
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 425
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  
Abstract
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 342
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  
Abstract
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 332
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  
Abstract
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 375
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  
Abstract
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 358
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  
Abstract
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 319
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  
Abstract
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 347
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  
Abstract
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 370
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  
Abstract
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 362
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  
Abstract
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 418
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  
Abstract
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 325
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  
Abstract
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 338
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  
Abstract
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 476
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, 674 KiB  
Abstract
Analysis and Development of Rotational Angle Sensor
by Yu-Wen Chen and Cheng-Yao Lo
Proceedings 2024, 97(1), 25; https://doi.org/10.3390/proceedings2024097025 - 15 Mar 2024
Viewed by 402
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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3 pages, 582 KiB  
Abstract
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 403
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  
Abstract
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 431
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  
Abstract
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 421
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  
Abstract
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 405
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  
Abstract
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 390
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  
Abstract
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 321
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  
Abstract
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 585
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  
Abstract
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 359
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  
Abstract
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 318
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  
Abstract
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 340
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  
Abstract
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 646
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  
Abstract
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 379
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  
Abstract
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 367
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  
Abstract
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 385
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  
Abstract
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 404
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  
Abstract
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 397
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  
Abstract
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 399
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  
Abstract
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
Cited by 1 | Viewed by 384
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  
Abstract
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 661
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  
Abstract
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 365
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  
Abstract
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 323
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  
Abstract
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 359
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  
Abstract
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 389
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  
Abstract
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 418
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  
Abstract
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 452
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  
Abstract
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 438
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  
Abstract
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 386
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  
Abstract
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 398
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  
Abstract
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 434
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  
Abstract
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 425
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  
Abstract
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 423
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  
Abstract
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 446
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  
Abstract
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 900
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  
Abstract
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 414
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  
Abstract
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 395
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  
Abstract
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 339
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  
Abstract
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 411
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  
Abstract
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 482
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  
Abstract
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 395
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  
Abstract
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 411
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  
Abstract
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 416
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  
Abstract
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 398
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  
Abstract
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 370
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  
Abstract
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 437
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  
Abstract
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 460
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  
Abstract
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 479
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  
Abstract
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 414
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 εr = 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 εr = 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 εr = 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  
Abstract
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 1030
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  
Abstract
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 457
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  
Abstract
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 445
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  
Abstract
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 417
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  
Abstract
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 423
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  
Abstract
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 424
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  
Abstract
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 554
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  
Abstract
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 410
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  
Abstract
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 375
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  
Abstract
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 1328
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  
Abstract
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 373
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  
Abstract
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 378
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  
Abstract
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 405
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  
Abstract
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 384
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  
Abstract
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 365
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  
Abstract
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 355
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  
Abstract
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 391
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  
Abstract
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 376
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  
Abstract
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 380
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  
Abstract
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 413
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  
Abstract
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 374
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  
Abstract
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 348
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 fr. A conductive target placed at different positions inside the pipe modifies the inductance of the coil, and in turn, fr. An external interrogation coil (IC) electromagnetically coupled to the IS allows the fr 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 fr0 = 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 ∆ fr = 180 kHz at x = 0. Full article
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3 pages, 651 KiB  
Abstract
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 448
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  
Abstract
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 356
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  
Abstract
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 365
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  
Abstract
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 408
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  
Abstract
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 377
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  
Abstract
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 404
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  
Abstract
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 337
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  
Abstract
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 362
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  
Abstract
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 415
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  
Abstract
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 384
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  
Abstract
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 369
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  
Abstract
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 391
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  
Abstract
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 390
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  
Abstract
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 355
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  
Abstract
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 288
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  
Abstract
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 358
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  
Abstract
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 458
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  
Abstract
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 307
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  
Abstract
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 342
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  
Abstract
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 335
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  
Abstract
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 455
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  
Abstract
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 359
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  
Abstract
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 408
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  
Abstract
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 383
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  
Abstract
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 411
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  
Abstract
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 493
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  
Abstract
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 427
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  
Abstract
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 430
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  
Abstract
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 2111
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  
Abstract
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 393
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  
Abstract
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 390
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  
Abstract
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 386
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  
Abstract
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 2270
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  
Abstract
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 2214
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  
Abstract
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 385
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  
Abstract
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 470
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  
Abstract
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 389
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  
Abstract
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 425
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  
Abstract
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 380
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  
Abstract
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 430
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  
Abstract
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 494
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  
Abstract
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 429
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  
Abstract
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 406
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  
Abstract
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 2202
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  
Abstract
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 416
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  
Abstract
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 439
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  
Abstract
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 510
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  
Abstract
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 2328
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  
Abstract
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 2271
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  
Abstract
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 550
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  
Abstract
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 480
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  
Abstract
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 484
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  
Abstract
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 511
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  
Abstract
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 446
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  
Abstract
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 482
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·ν·Dg3, 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  
Abstract
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 2232
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  
Abstract
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 358
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  
Abstract
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 443
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  
Abstract
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 415
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  
Abstract
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 2338
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  
Abstract
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 406
Abstract
A facile and clean-room compatible approach to Ni nitride (NixNy) synthesis is proposed, based on a reactive sputtering deposition technique. NixNy 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 (NixNy) synthesis is proposed, based on a reactive sputtering deposition technique. NixNy thin films were deposited at different N2 partial pressures, after which their electrocatalytic properties towards glucose oxidation were investigated. Relative to the bare Ni, NixNy thin films sputtered at low N2 partial pressures exhibited a decreased linear range (0–5 mM) and sensitivity. Contrarily, NixNy 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 NixNy 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  
Abstract
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 408
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  
Abstract
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 2232
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  
Abstract
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 491
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  
Abstract
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 470
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  
Abstract
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 451
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  
Abstract
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 474
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  
Abstract
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 498
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 PM2.5, respectively. Full article
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3 pages, 885 KiB  
Abstract
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 445
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  
Abstract
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 435
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  
Abstract
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 2182
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  
Abstract
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 466
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  
Abstract
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 452
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  
Abstract
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 505
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  
Abstract
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 515
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  
Abstract
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 456
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  
Abstract
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 418
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  
Abstract
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 451
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  
Abstract
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 2062
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  
Abstract
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 2030
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  
Abstract
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 1966
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  
Abstract
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 437
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  
Abstract
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 410
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  
Abstract
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 1291
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  
Abstract
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 440
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  
Abstract
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 481
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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