Hardware doi: 10.3390/hardware4020010

Authors: Priyanshi Nitinbhai Patel Matthew D. Gacura Davide Piovesan

Organic waste management remains a pressing environmental and economic challenge, particularly in small-scale or domestic contexts where access to industrial composting technologies is limited. This study investigates the performance of the BSG-2 fermenter, a low-cost aerobic system designed to convert brewery spent grain (BSG) and vegetable waste into nutrient-rich compost through solid-state fermentation. The fermenter, constructed from food-grade plastic, relied on intermittent forced aeration, and manual temperature and pH control to sustain microbial activity. Temperature, pH, and substrate degradation were monitored throughout a complete fermentation cycle. The system achieved consistent bio-thermal performance with peak temperatures of approximately 32 °C and a substrate volume reduction of 30–40%, confirming active microbial metabolism and substantial organic matter degradation. Minimal odor generation and low energy input highlighted the fermenter’s environmental suitability. While occasional anaerobic pockets and limited heat retention were observed, these limitations could be addressed through improved insulation and automated aeration. The sustained mesophilic heat generation observed in the system may also present opportunities for low-grade thermal recovery in small-scale applications, such as localized environmental conditioning, although the magnitude of heat produced is limited. Overall, the BSG-2 fermenter demonstrates a feasible, replicable approach to valorizing organic waste into compost and sustained mesophilic heat generation using simple, accessible materials, contributing to circular economy strategies and sustainable small-scale waste management.

Hardware doi: 10.3390/hardware4020009

Authors: Mohamed Naguib Afifi Riham Zakaria Lashin Ahmed M. F. Elshahat

In autologous microtia reconstruction, achieving optimal skin adherence to the cartilage framework is critical for aesthetic success. This study validates a novel, low-cost closed suction system assembled from a 20 mL syringe, a 5 mL syringe barrel acting as a rigid internal lock, and a fenestrated butterfly cannula. In a prospective cohort of 100 consecutive cases, the system effectively coapted the skin flap in all patients without major complications. Clinical data revealed a mean drainage duration of 6 days and 19 h (95% CI: 6 d 11 h to 7 d 4 h) and a mean collected fluid volume of 17.36 mL (95% CI: 16.77–17.95 mL). Blinded expert evaluation using the weighted 13-point Sharma scale demonstrated “Excellent” framework definition in 81.7% of patients. This system offers exceptional reliability and disruptive cost-efficiency, achieving stable vacuum pressure at a production cost of approximately 0.60 USD. These findings provide a compelling proof-of-concept for an accessible, high-performance alternative in auricular reconstruction, establishing a robust foundation for broader clinical adoption and future comparative validation in resource-limited surgical settings.

Hardware doi: 10.3390/hardware4020008

Authors: Mathias Stahl Kavai José Alberto Fracassi da Silva

Lab-on-a-chip devices offer high efficiency, low volume and fast analytical measurement, but their use is still niche. A key component for these devices is the detector, and one common type of detection is fluorescence spectroscopy. However, in some cases the detector can be bulky and lose the appeal of small-footprint devices. To make lab-on-a-chip devices truly compact, detectors must also be compact. In this paper we discuss the use of simple and low-cost commercial multispectral sensors for use in lab-on-a-chip devices, more specifically for fluorescence detection, which we demonstrate to allow detection on nanomolar scale with a simple experimental setup.

Hardware doi: 10.3390/hardware4020007

Authors: Camila Pedano-Medina Paolo Petagna Susanne Gleissle

Supercritical carbon dioxide (sCO2) is characterized by low viscosity and a peak in specific heat capacity near the pseudo-critical point, making it a promising coolant for microelectronics. However, most existing sCO2 test rigs are designed for large-scale thermodynamic cycle studies and lack the capability for controlled, localized heat transfer measurements in small channels. This work presents CO2-SASS (Scientific Assessment of heat transfer in the Supercritical State), a modular, high-pressure test rig designed to measure local heat transfer coefficients and pressure drops in stainless-steel tubes with diameters on the order of 1–3 mm. The system provides independent control of pressure, mass flow and heating, with direct local wall and fluid temperature as well as precise absolute and differential pressure measurements. Particular emphasis is placed on high-accuracy temperature acquisition, including individual thermocouple calibration and cold-junction bias correction. A detailed uncertainty analysis highlights the dominant role of temperature measurement accuracy, especially for small wall–fluid temperature differences near the pseudo-critical point.

Hardware doi: 10.3390/hardware4010006

Authors: Nathaniel Viewegh Harrison Holloway Rainey Biggerstaff Joseph Bruce Herzog Christopher Martin Stanley

Wide bandgap (WBG) semiconductors such as gallium nitride (GaN) and silicon carbide (SiC) have revolutionized modern power electronics by enabling devices that operate at higher voltages, temperatures, and switching frequencies than their silicon counterparts. This paper reviews the material properties, device architectures, fabrication techniques, and thermal management strategies that underpin the performance of GaN and SiC technologies. We highlight key trade-offs between GaN and SiC in terms of voltage blocking capability, switching efficiency, and thermal robustness and discussed their application in electric vehicles, renewable energy systems, and power converters. Market adoption trends and manufacturing challenges are also analyzed, with attention to cost-performance dynamics and packaging innovations. Finally, we address the critical role of thermal boundary resistance and emerging reliability solutions, providing a perspective on the future trajectory of WBG device research and commercialization.

Hardware doi: 10.3390/hardware4010005

Authors: Beau-Gard Jules Hougbenou Xiao Fei Henrik Christensen Kafoui Rémi E. Akotègnon Tram Thuy Nguyen Anders Dalsgaard John Elmerdahl Olsen Yaovi Mahuton Gildas Hounmanou

Long-read sequencing technologies, particularly those developed by Oxford Nanopore Technologies (ONT), have transformed genome sequencing by enabling high-resolution analysis of complex microbial communities. Among ONT devices, the MinION remains affordable and scalable for low-resource settings. However, its limited onboard computing power constrains high-accuracy basecalling and limits its ability to address inherent sequencing errors effectively. To overcome these constraints, we assembled a streamlined in-house workflow that integrates at least five MinION devices with a GPU-powered workstation running Ubuntu 20 and MinKNOW. Rather than a new sequencing platform, this “home-made GridION” represents a practical integration of existing ONT devices with dedicated computing resources. At its core is a live basecalling pipeline capable of handling both FAST5 and POD5 file formats. The system supports high-throughput basecalling using Guppy on FAST5 files as well as Dorado on POD5 files, ensuring compatibility with both legacy and current ONT data standards. File monitoring is automated via inotifywait, enabling immediate detection of new files, real-time basecalling, and organized output of FASTQ batches. Beyond basecalling, we implemented an automated downstream pipeline for metagenomic analysis, enabling taxonomic profiling and detection of antimicrobial resistance genes (ARG). Tested on 10 hospital wastewater samples, the workflow generated at least 500,000 reads per sample within six hours, which were analysed for antimicrobial resistance gene abundance. This demonstrates its potential as an open, scalable hardware/software platform that extends the utility of MinION sequencing for microbial genomics in resource-limited environments. The setup can channel as many MinIONs as available USB ports, with a ratio of 1 MK1D for 1 TB of storage capacity on the associated computer.

Hardware doi: 10.3390/hardware4010004

Authors: Gabriel G. Muñoz Martín J. Millicovsky Albano Peñalva Juan I. Cerrudo Juan M. Reta Martín A. Zalazar

Quartz Crystal Microbalance with Dissipation monitoring (QCM-D) systems are widely used for the real-time analysis of mass changes and viscoelastic properties in biological samples, enabling applications such as biomolecular interaction studies, biosensing, and fluid characterization. However, their accessibility has been limited by high acquisition costs. To address this limitation, a low-cost, open-source QCM-D system was developed. Unlike other affordable, open-hardware alternatives, this system is specifically optimized for potential biomedical applications by integrating active thermal control to preserve the physical properties of the samples and dissipation monitoring to characterize their viscoelastic behavior. A 10 MHz quartz crystal with a sensor module and a control and acquisition unit were integrated. The full system was built at a total cost below USD 500. Performance validation showed a temperature stability of ±0.13 °C, a frequency stability of ±2 Hz in air, and a limit of detection (LOD) of 0.46% polyethylene glycol (PEG), thereby enabling stable, reproducible measurements and the sensitive detection of small mass and interfacial changes in low-concentration samples. These results demonstrate that key QCM-D sensing capabilities can be achieved at a fraction of the cost, providing an accessible and reliable platform for potential biomedical research.

Hardware doi: 10.3390/hardware4010003

Authors: Abdul Basit Samuel Liu

Dynamic demand response (DDR) is the process of shifting power consumption towards periods of lower demand based on real-time energy pricing data. It is a flexibility measure utilised in the decarbonisation of the UK’s power system to reduce peak demand. Dynamic time-of-use (dTOU) tariffs, such as Agile Octopus, incentivise DDR by providing half-hourly electricity prices for each day. Through this incentive, households are offered the opportunity to reduce their energy costs by applying DDR to energy-intensive, deferrable loads. This paper presents an open-source, Internet of Things (IoT)-based system designed to automate DDR and streamline its implementation. The system identifies the period of lowest electricity prices and activates a relay during this period each day. For validation, the system was tested over a one-month experiment, which showed that, in a favourable scenario, it could reduce an appliance’s electricity costs by up to 44%. These results highlighted the system’s potential to deliver substantial energy cost savings, while also encouraging households to participate in flexibility measures that alleviate pressure on the National Grid.

Hardware doi: 10.3390/hardware4010002

Authors: Celso Márquez-Sánchez Jacobo Sandoval-Gutiérrez Daniel Librado Martínez-Vázquez

This work presents the development of a differential-drive wheeled mobile robot educational prototype, manufactured using 3D additive techniques. The robot is powered by an embedded ARM-based computing system and uses open-source software. To validate the prototype, a trajectory-tracking task was successfully implemented. The aim of this contribution is to provide an easily replicable prototype for teaching automatic control and related engineering topics in academic settings.

Hardware doi: 10.3390/hardware4010001

Authors: Albert P. Song Alice Tang Dunji Yu Ke An

High-flux neutron beams and high-efficiency detectors enable rapid neutron diffraction measurements at the Engineering Materials Diffractometer (VULCAN) at the Spallation Neutron Source (SNS), Oak Ridge National Laboratory (ORNL). To optimize beam time utilization, efficient sample exchange, alignment, and automated measurements are essential. Recent advances in artificial intelligence (AI) have expanded the capabilities of robotic systems. Here, we report the development of a Robotic Interactive Control and Handling (RICH) system for sample handling at VULCAN, designed to support high-throughput experiments and reduce overhead time. The RICH system employs a six-axis desktop robot integrated with AI-based computer vision models capable of recognizing and localizing samples in real time from instrument and depth-resolving cameras. Vision algorithms combine these detections to align samples with designated measurement positions or place them within complex sample environments such as furnaces. This integration of machine learning-assisted vision with robotic handling demonstrates the feasibility of autonomous sample detection and preparation, offering a pathway toward fully unmanned neutron scattering experiments.

Hardware doi: 10.3390/hardware3040017

Authors: Danilo A. Coletto Gallego Rocío B. Pérez David Douglas de Sousa Fernandes Rodrigo M. Santos Gabriel Eggly

Field instruments are an emerging topic because they facilitate the extraction of qualitative and quantitative information from samples at a sampling site. This work focused on the development of an open-source potentiostat, analyzing the construction feasibility and quality of a lab-made device with an all-in-one design, low cost, good response, and portability, compared to expensive, commercial, laboratory-oriented devices. The design and development of the hardware, as well as the corresponding software, was considered, allowing the device to be expandable in the future through upgrades. Thus, an economical and portable functional prototype was developed, with good linear response and the capacity to perform, in this first approach, cyclic, square wave, and stripping voltammetry with a range and sweep speed between ±2.048 V and 1000 mV/s, respectively, with waveform frequencies up to 110 Hz and an accuracy of ±1 nA.

Hardware doi: 10.3390/hardware3040016

Authors: Paulo Roberto Tercio Zamperlini Iuri da Silva Diniz Érica Silva Pinto Saulo Neves Matos Luis Guilherme Uzeda Garcia Alan Kardek Rêgo Segundo

The S11D mining complex in Brazil, situated in Pará state, extracts 20 million tons of iron each quarter. Connecting via a standard 802.11b/g/n wireless network is crucial for mine operations across vast distances. A local team employs a network monitoring tool called the Ekahau Site Survey to guarantee the proper functioning of the network. However, due to the harsh terrain and the dangerous nature of S11D operations, this tool fails to gather data from all points of interest, resulting in interpolated maps that may not accurately represent the network’s overall quality. In this work, we propose a platform that can be attached to mobile machines during operations to automatically collect network parameters, such as channelization, RSSI, latency, packet loss, and bandwidth, without requiring human intervention. Using these network data, we generate an RSSI map using Kriging, which the local team can use. Comparison tests conducted in the laboratory and the field demonstrate that the platform performs similarly to Ekahau in capturing network parameters, ensuring its use in day-to-day operations for mapping.

Hardware doi: 10.3390/hardware3040015

Authors: Jesús E. Miranda-Vega Erick Y. Nuñez-Patrón Guillermo Prieto-Avalos Wendy Flores-Fuentes Oleg Sergiyenko Wendy García-González Loriz Victoria Márquez-Ramirez Rubén Castro-Contreras Rafael I. Ayala-Figueroa

To support the understanding of cardiovascular monitoring and physiological signal processing, we present a portable, open-source photoplethysmography (PPG) acquisition platform developed for educational and research applications. The system is built entirely with commercial off-the-shelf components and centers around an ESP32 microcontroller, which performs high-speed analog signal acquisition at 500 samples per second, alongside real-time control, and wireless communication. A cross-platform, Python-based graphical user interface enables real-time signal visualization, peak detection, and the computation of heart rate variability (HRV) metrics, including RMSSD and SDNN, during offline analysis. All hardware and software resources are openly available to enable replication and further development. This project emphasizes accessibility, transparency, and hands-on learning in biomedical signal acquisition. System functionality is validated offline through controlled data collection from human subjects, demonstrating results consistent with established HRV benchmarks.

Hardware doi: 10.3390/hardware3040014

Authors: Kasper Eliasson Maria Strømme Chao Xu

With the growing interest in fabricating nanofiltration membranes using novel materials and techniques, there is an increasing need to evaluate the practical viability of innovative membranes at the early stages of development. In many materials research laboratories, access to professionally manufactured membrane-evaluation systems may be limited. Here we present a pressure-driven filtration system for evaluation of nanofiltration membranes, which can be constructed from 3D-printed parts and widely available off-the-shelf components at a cost of approximately 60 €. The system uses a stirred cross-flow design capable of circulating the feed solution in the filter cell and maintaining a stable solute concentration during extended filtration experiments—as in conventional cross-flow cells. It is suitable for the filtration of aqueous solutions containing dyes, inorganic salts, and dilute acids. Validation was performed by filtering a 2000 mg L−1 MgSO4 solution through a Veolia RL membrane at 7.6 bar, achieving a 96.5% rejection rate and a permeance of 7.5 L m−2 h−1 bar−1 after 24 h of continuous operation.

Hardware doi: 10.3390/hardware3040013

Authors: Gianluca Cornetta Souhail Fatimi Arfan Kochaji Omar Moussa Majed Saleh Almaleky Mimoun Lamrini Abdellah Touhafi

This paper introduces an innovative open-source hardware platform designed for multi-sensor environmental monitoring, rooted in the outcomes of the “Smart Water” project. The primary objective of this platform is to facilitate advanced PCB design education by offering students a modular, expandable, and feature-rich embedded hardware environment. The platform serves as a practical training ground, enabling students to experiment with diverse sensing techniques and refine their skills in the intricacies of PCB design. The “Smart Water” project, which forms the foundation of this educational platform, has yielded invaluable insights into environmental monitoring technologies. Leveraging these findings, our hardware platform integrates a variety of sensors capable of measuring crucial environmental parameters such as water quality, temperature, and atmospheric conditions. The modular design allows students to explore various sensor combinations and experiment with custom configurations, fostering a deeper understanding of sensor integration and optimization. Key features of the platform include its expandability, encouraging students to develop add-on modules for specific applications or to enhance existing functionalities. This approach not only promotes creativity but also instills a sense of ownership and collaboration among students, as they contribute to the continual evolution of the hardware platform. The feature-rich nature of the embedded system enables comprehensive experimentation in sensor data acquisition, processing, and communication, providing a holistic learning experience.

Hardware doi: 10.3390/hardware3040012

Authors: Marks Jalisevs Hamza Qadeer David O’Connor Mingming Liu Shirley M. Coyle

Particulate matter (PM2.5) is a critical indicator of air quality and has significant health implications. This study presents the development and evaluation of a custom-built PM2.5 device, named the P-Tracker, designed to offer an accessible alternative to commercially available air quality monitors. This paper presents the design framework used to address the requirements of a low-cost, accessible device which meets the performance of existing commercial systems. Step-by step build instructions are provided for hardware and software development and connection to the P-tracker open access website which displays the data and interactive map. To demonstrate the performance, the P-Tracker was compared against leading consumer devices, including the AtmoTube Pro by AtmoTech Inc., Flow by Plume Labs, View Plus by Airthings, and the Smart Citizen Kit 2.1 by Fab Lab Barcelona, across four controlled tests. The tests included: (1) a controlled paper combustion test in which all devices were exposed to combustion aerosols in a sealed environment alongside the DustTrak 8530 (TSI Incorporated, Shoreview, MN, USA), used as the gold standard reference, where the P-Tracker achieved a Pearson correlation of 0.99 with DustTrak over the final measurement period; (2) an outdoor test comparing readings with a stationary reference sensor, Osiris (Turnkey Instruments Ltd., Rudheath, UK), where the P-Tracker recorded a mean PM2.5 concentration of 3.08 µg/m3, closely aligning with the Osiris measurement of 3.53 µg/m3 and achieving a Pearson correlation of 0.77; (3) a controlled indoor air quality assessment, where the P-Tracker displayed stable readings with a standard deviation of 0.11 µg/m3, comparable to the AtmoTube Pro; and (4) a real-world kitchen environment test, where the P-Tracker effectively captured fluctuations in PM2.5 levels due to cooking activities, maintaining a consistent response with the DustTrak reference. The results indicate varied degrees of agreement across devices in different conditions, with the P-Tracker demonstrating strong correlation and low error margins in high-pollution and controlled scenarios. This research underscores the potential of open-source, low-cost, custom-built air quality sensors which may be developed and deployed by communities to provide hyperlocal measurements of air pollution.

Hardware doi: 10.3390/hardware3030011

Authors: Bruno Sanchez-Garcia Juan Antonio Rojas-Quintero Hedy Cesar Ramirez-de-Avila Eusebio Bugarin Selene Lilette Cardenas-Maciel Nohe Ramon Cazarez-Castro

This article presents an experimental platform for testing friction models used by control strategies on a one-degree-of-freedom mechanical motion control system. This platform aims to carry out experiments to estimate dry friction parameters and related motion control strategies. The presented device can be built using low-cost components available in most laboratories. The platform enables both a correct friction parameters estimation and the experimental validation of related motion control strategies. The proposed platform can be applied to the validation of a wide spectrum of parameter identification and motion control procedures. Experimental results illustrate the usability of the proposed device for research purposes. However, the platform could be used as an educational device to illustrate the performance of specific friction models with various control strategies.

Hardware doi: 10.3390/hardware3030010

Authors: Juan David Daza Flórez Gabriel Andrés Payanene Zambrano Sebastián Roa Prada

This paper presents the development, modeling, and validation of a scaled UAV-VTOL low-cost prototype equipped with a jet propulsion system with vertical take-off and landing capabilities. The prototype is designed as an experimental testbed for reusable rocket control strategies, with a particular focus on thrust vectoring and landing stabilization. The study begins with the evolution of the CAD, followed by a guide for the correct assembly of the device. The development of the electronic system included the integration of an ARM Cortex-M7 microcontroller, inertial sensors, and a LIDAR-based altitude measurement system; this was enhanced by a Kalman estimator to mitigate the sensor’s noise. A series of experimental tests were conducted to characterize the key subsystems. Actuator characterization improved the linearized nozzle control model, ensuring predictable thrust redirection. The test bench results confirmed the EDF’s thrust curve and its ability to sustain controlled flight, despite minor losses due to battery discharge variations. Furthermore, state-space modeling aided the development of controllers for altitude stabilization and attitude control, with simulations proving the feasibility of maintaining stable flight conditions. Experimental validation confirmed that the prototype provides a practical platform for future research in reusable rocket dynamics and autonomous landing algorithms.

Hardware doi: 10.3390/hardware3030009

Authors: Martin Millicovsky Luis Schierloh Pablo Kler Gabriel Muñoz Juan Cerrudo Albano Peñalva Juan Reta Martin Zalazar

Love wave surface acoustic wave (LSAW) sensors are crystal resonators known for their high potential for biosensing applications due to their high sensitivity, real-time detection, and compatibility with microfluidic systems. Commercial LSAW devices are costly, and manufacturing them is even more expensive, making accessibility a significant challenge. Additionally, their use requires specialized systems, and with only a few manufacturers dominating the market, most available solutions are proprietary, limiting customization and adaptability for specific research needs. In this work, a low-cost open-source LSAW biosensing system prototype was developed based on a commercially acquired resonator. The development integrates microfluidics through a polydimethylsiloxane (PDMS) chip, low-cost electronics, and both 3D printed ultraviolet (UV) resin and polylactic acid (PLA) parts. The instrument used for measurements was a vector network analyzer (VNA) that features open-source software. The code was customized for this study to enable real-time, label-free biosensing. Experimental validation consisted of evaluating the sensitivity and repeatability of the system, from the setup to its use with different fluids. Results demonstrated that the development is able to advance to more complex applications.

Hardware doi: 10.3390/hardware3030008

Authors: Mario Gazziro Marcio Luís Munhoz Amorim Marco Roberto Cavallari João Paulo Carmo Oswaldo Hideo Ando Júnior

This project aimed to develop personal protective equipment (PPE) that provides full biological protection for the general public without the need for extensive training to use the equipment. With the proposal to develop a device guided by a smartphone monitoring application (to guide the user on the replacement of perishable components, ensuring their safety and biological protection in potentially contaminated places), the embedded electronics of this equipment were built, as well as their control system, including a smartphone app. Thus, a device was successfully developed to monitor and assist individuals in using an advanced PPE device.

Hardware doi: 10.3390/hardware3030007

Authors: Felix Herbst Sven Suppelt Niklas Schäfer Romol Chadda Mario Kupnik

Robotic arms are used in a wide range of industrial and medical applications. However, for research and education, users often face a trade-off between costly commercial solutions with no adaptability and open-source alternatives that lack usability and functionality. In education, this problem is exacerbated by the prohibitive cost of commercial systems or simplifications that distort learning. Thus, we present HELENE, an open-source robot with six degrees of freedom, closed-loop position control, and robot operating system (ROS) integration. The modular design of the robot, printed on a commercial 3D printer, and its integrated custom electronics allow for easy customization for research purposes. The joints are driven by standard stepper motors with closed-loop position control using absolute encoders. The ROS integration guarantees widespread control options and integration into existing environments. Our prototype, tested in accordance with ISO 9283, has a small positional accuracy error of 8.4 mm and a repeatability error of only 0.87 mm with a load capacity of 500 g at a reach of 432 mm. Ten prototypes were built and used in various research and education applications, demonstrating the versatile applicability of this open-source robot, closing the gap between reliable commercial systems and flexible open-source solutions.

Hardware doi: 10.3390/hardware3030006

Authors: Adrian Truszkiewicz Dorota Bartusik-Aebisher David Aebisher

The aim of this work was to design a coil for magnetic resonance imaging (MRI) and magnetic resonance spectroscopy (MRS) to analyze the morphology of cells in vitro. This newly developed hardware, due to compatibility to the 1.5-Tesla MRI scanner (GE Healthcare, Boston, MA, USA), allows for the characterization of cell cultures in vitro. To adapt a designed coil on the 1.5-Tesla MRI scanner, some changes in hardware and software were carried out. The advantage of the designed receiving circuit is the ability to perform MRI with a resolution of 80 μm × 80 μm pixel size. Additionally, this coil can be used to visualize cell cultures and tissue sections, which, due to their small dimensions, could not be imaged on standard MRS and MRI coils at 1.5 Tesla.

Hardware doi: 10.3390/hardware3020005

Authors: Nicholas Ross Delaney Heileman A. Gerrit Motes Anwi Fomukong Giorgio Bacelli Steven J. Spencer Dominic D. Forbush Kevin Dullea Ryan G. Coe

Wave energy converters are a nascent energy generation technology that harnesses the power in ocean waves. To assist in communicating both fundamental and complex concepts of wave energy, a small-scale portable wave tank and wave energy converter have been developed. The system has been designed using commercial off-the-shelf components, and all design hardware and software are openly available for replication. This project builds on prior research conducted at Sandia National Laboratories, particularly in the areas of WEC device design and control systems. By showcasing the principles of causal feedback control and innovative device design, SIWEED not only serves as a practical demonstration tool but also enhances the educational experience for users. This paper presents the detailed system design of this tool. Furthermore, via testing and analysis, we demonstrate the basic functionality of the system.

Hardware doi: 10.3390/hardware3020004

Authors: Jonathan E. Thompson

A novel temporally resolved settle-plate air sampler was developed using 3D printing technology to improve upon traditional passive air sampling methods. Conventional settle plates provide cumulative measurements of particle or microbial loads over an entire sampling period, lacking the temporal resolution necessary to identify specific contamination events. The described device integrates a petri plate within a 3D-printed housing featuring a narrow slit that exposes only a small portion of the plate to incoming particles. A rotary mechanism, driven by a mechanical clock motor, rotates the petri plate over 12 h, allowing for time-segmented sampling. Validation experiments demonstrated the device’s ability to accurately encode the temporal history of particle deposition using both aerosolized dyes and viable microbial spores. The device effectively correlated bioaerosol deposition with ambient wind conditions during outdoor sampling. The system is inexpensive (under USD 10), requires no specialized skills to assemble, and is compatible with existing settle plate methodologies. This innovation enhances the ability to conduct air quality assessments in critical environments, enabling data-driven decisions to mitigate contamination risks.

Hardware doi: 10.3390/hardware3020003

Authors: Yutaka Yoshida Emi Yuda Kiyoko Yokoyama

The ability to respond swiftly and accurately to visual stimuli is critical for safe driving. The traditional Psychomotor Vigilance Test (PVT) primarily assesses response time (RT) using finger inputs, but these do not directly evaluate foot responses essential for vehicle control. This study introduces a novel Foot Psychomotor Vigilance Test (Foot PVT) designed to measure the RTs of the foot in response to simulated traffic lights. The Foot PVT integrates a traffic light display interface with a three-pedal system, simulating basic driving conditions. RTs are recorded for three colors (blue, yellow, red) displayed in a randomized order, and the response accuracy is evaluated based on the pedal input. The system also measures correction times for errors, offering insights into a driver’s ability to recover from mistakes. Validation experiments were conducted with eleven healthy younger (25 ± 3 years) and eleven healthy older adult participants (73 ± 4 years). The results showed that the older adult participants (818 ± 84 ms) exhibited significantly longer RTs than the younger participants (725 ± 74 ms, p = 0.016), consistent with age-related cognitive and motor decline. Interestingly, the older participants had fewer false starts, suggesting a compensatory cautious approach to responding. The Foot PVT has the potential to serve as a low-cost, efficient screening tool for evaluating driving fitness, particularly for older adult individuals and novice drivers.

Hardware doi: 10.3390/hardware3010002

Authors: Jonathan E. Thompson

Additive manufacturing (AM), commonly known as 3D printing, is revolutionizing manufacturing, medicine, and engineering. This perspective explores recent breakthroughs that position AM as a disruptive technology. Innovations like volumetric additive manufacturing (VAM) enable rapid, high-resolution, layer-free fabrication, overcoming limitations of traditional methods. Multi-material printing allows the integration of diverse functionalities—fluid channels, structural elements, and possibly functional electronic circuits—within a single device. Advances in material science, such as biocompatible polymers, ceramics, and transparent silica glass, expand the applicability of AM across healthcare, aerospace, and environmental sectors. Emerging applications include custom implants, microfluidic devices, various sensors, and optoelectronics. Despite its potential, challenges such as scalability, material diversity, and process optimization remain active and critical research areas. Addressing these gaps through interdisciplinary collaboration over the coming decade will solidify AM’s transformative role in reshaping production and fostering innovation across many industries.

Hardware doi: 10.3390/hardware3010001

Authors: Muhammad Umer Mushtaq Hein Venter Avinash Singh Muhammad Owais

Energy harvesting wireless sensor networks (EH-WSNs) appear as the fundamental backbone of research that attempts to expand the lifespan and efficiency of sensor networks positioned in resource-constrained environments. This review paper provides an in-depth examination of latest developments in this area, highlighting the important components comprising routing protocols, energy management plans, cognitive radio applications, physical layer security (PLS), and EH approaches. Across a well-ordered investigation of these features, this article clarifies the notable developments in technology, highlights recent barriers, and inquires avenues for future revolution. This article starts by furnishing a detailed analysis of different energy harvesting methodologies, incorporating solar, thermal, kinetic, and radio frequency (RF) energy, and their respective efficacy in non-identical operational circumstances. It also inspects state-of-the-art energy management techniques aimed at optimizing energy consumption and storage to guarantee network operability. Moreover, the integration of cognitive radio into EH-WSNs is acutely assessed, highlighting its capacity to improve spectrum efficiency and tackle associated technological problems. The present work investigates ground-breaking methodologies in PLS that uses energy-harvesting measures to improve the data security. In this review article, these techniques are explored with respect to classical encryption and discussed from network security points of view as well.The assessment furthers criticizes traditional routing protocols and their significance in EH-WSNs as well as the balance that has long been sought between energy efficiency and security in this space. This paper closes with the importance of continuous research to tackle existing challenges and to leverage newly available means as highlighted in this document. In order to adequately serve the increasingly changing requirements of EH-WSNs, future research will and should be geared towards incorporating AI techniques with some advanced energy storage solutions. This paper discusses the integration of novel methodologies and interdisciplinary advancements for better performance, security, and sustainability for WSNs.

Hardware doi: 10.3390/hardware2040015

Authors: Adham Salih Navit Roth Oshri Buganim Avishag Deborah Pelosi

The evaluation of soft tissue biomechanical properties is of paramount importance not only for a comprehensive understanding of human physiology and physiopathology, but also in the research and development of bio-compatible artificial tissues with viscoelastic properties. Contrarily to standard tensile testing devices, a system intended for biomaterials testing should consider low stress and high strain ranges, characteristic of human tissues; moreover, such a system should enable the ex vivo simulation of biological environmental conditions. Commercial solutions address these challenges, although they are expensive for most academic and research institutions. This study presents a low-cost open-source design solution for soft tissue tensile testing, offering an affordable solution, yet without compromising the high quality and precision of the results. The proposed uniaxial tensile system allows for sample testing at room temperature as well as in a temperature-controlled liquid environment. Moreover, custom clamps ensure the fixation of tissue samples without slipping or tearing. System validation is performed using the tensile testing of springs and 3D-printed soft polymeric samples, demonstrating accurate results compared to the available data. The system is suitable for educational, research, and development applications.

Hardware doi: 10.3390/hardware2040014

Authors: Artem Sobko Nikolai Yudanov Larissa V. Panina Valeriya Rodionova

Visualizing magnetic fields is essential for studying the operation of electromagnetic systems and devices that use permanent magnets or magnetic particles. However, commercial devices for this purpose are often expensive due to their complex designs, which may not always be necessary for specific research needs. This work presents a method for designing an automated laboratory setup for magnetic cartography, utilizing a 3D printer to produce structural plastic components for the scanner. The assembly process is thoroughly described, covering both the hardware and software aspects. Spatial resolution and mapping parameters, such as the number of data points and the collection time, were configured through software. Multiple tests were conducted on samples featuring flat inductive coils on a printed circuit board, providing a reliable model for comparing calculated and measured results. The scanner offers several advantages, including a straightforward design, readily available materials and components, a large scanning area (100 mm × 100 mm × 100 mm), a user-friendly interface, and adaptability for specific tasks. Additionally, the integration of a pre-built macro enables connection to any PC running Windows, while the open-source microcontroller code allows users to customize the scanner’s functionality to meet their specific requirements.

Hardware doi: 10.3390/hardware2040013

Authors: Marc-Aurèle Boillat Peter C. Hauser

The probe was designed for the measurement of DC voltages of up to 30 kV from high impedance sources. It is based on a resistive divider with a total resistance of 200 GΩ and a step-down factor of 10’000. In order to allow the measurement of the stepped down voltage with a conventional multimeter without loading, the signal was buffered with an operational amplifier. The device was calibrated against a commercial probe using a low impedance high voltage source. A linear relationship was obtained for a high impedance resistive ladder for voltages between 3 and 30 kV, with a coefficient of determination (R2) of 0.9999. The low-cost device (ca. US $200) fills an application niche not addressed by commercial products.

Hardware doi: 10.3390/hardware2040012

Authors: John LaRocco Qudsia Tahmina John Simonis Taylor Liang Yiyao Zhang

Tactile maps are widely recognized as useful tools for mobility training and the rehabilitation of visually impaired individuals. However, current tactile maps lack real-time versatility and are limited because of high manufacturing and design costs. In this study, we introduce a device (i.e., ClaySight) that enhances the creation of automatic tactile map generation, as well as a model for wearable devices that use low-cost laser imaging, detection, and ranging (LiDAR,) used to improve the immediate spatial knowledge of visually impaired individuals. Our system uses LiDAR sensors to (1) produce affordable, low-latency tactile maps, (2) function as a day-to-day wayfinding aid, and (3) provide interactivity using a wearable device. The system comprises a dynamic mapping and scanning algorithm and an interactive handheld 3D-printed device that houses the hardware. Our algorithm accommodates user specifications to dynamically interact with objects in the surrounding area and create map models that can be represented with haptic feedback or alternative tactile systems. Using economical components and open-source software, the ClaySight system has significant potential to enhance independence and quality of life for the visually impaired.

Hardware doi: 10.3390/hardware2030011

Authors: Jack Wilkie Georg Rauter Knut Möller

Screws are a versatile method of fixation and are often used in orthopaedic surgery. Various specialised geometries are often used for bone screws to optimise their fixation strengths in limited spaces at the expense of manufacturing costs. Additionally, ongoing research is looking to develop systems/models to automatically optimise bone screw tightening torques. For both applications, it is desirable to have a test rig for inserting screws in a regulated, instrumented, and repeatable manner. This work presents such a test rig primarily used for the validation of optimal torque models; however, other applications like the above are easily foreseeable. Key features include controllable insertion velocity profiles, and a high rate measurement of screw torque, angular displacement, and linear displacement. The test rig is constructed from mostly inexpensive components, with the primary costs being the rotational torque sensor (approx. 2000 €), and the remainder being approximately 1000 €. This is in comparison to a biaxial universal testing machine which may exceed 100,000 €. Additionally, the firmware and interface software are designed to be easily extendable. The angular velocity profiling and linear measurement repeatability of the test rig is tested and the torque readings are compared to an off-the-shelf static torque sensor.

Hardware doi: 10.3390/hardware2030010

Authors: Ahmed Darwish Badawy Stefan Sfranciog Jorge Takeshi Hiranoyama Jaime Lacasta Ibarrola James Engstrom Kirollos Mikhail William Hunt Joshua Hartley Fatemeh Nasr Esfahani Amos Dexter

Formula Student (FS) competitions aim to prepare and encourage engineering students to participate in the progression of automotive and motorsport industries. The built racing cars adhere to strict regulations set by competition guidelines to ensure the safety of both teams and spectators. For electric racing cars, the high-voltage (HV) battery system usually operates within a voltage range between 100 V to 600 V to supply the motor and its controller with the required electrical power. It is essential to ensure that these components are operating effectively to minimize battery and motor current as well as to ensure efficient and reliable performance throughout the race. A low-voltage control system (LVCS), usually operating at 12 V, is used to coordinate a wide array of critical operational and safety functions to control the HV system. These functions include: (1) turning on/off procedures, (2) monitoring speed, voltage, and current, (3) interfacing with pedals, (4) controlling dashboard features, (5) managing lighting, (6) facilitating data communication, and (7) implementing safety protocols. The design and operation of the LVCS are crucial for compliance with safety regulations and enhancing the FS electric racing car (FSERC) performance. This details and discusses the design procedures of the LVCS, using the Lancaster E-Racing (LER) FSERC as a case study. The LER car employs a 400 V battery system to power a 68-kW permanent manet synchronous motor (PMSM) using a three-phase voltage source inverter. Using mathematical analysis, SIMULINK/MATLAB® computer simulations, and the experimental real-data results provided by the LER FSERC, this study seeks to offer valuable insights regarding the LVCS practical implementation and optimization.

Hardware doi: 10.3390/hardware2020009

Authors: Domenico Suriano

Air quality monitoring is performed by agencies using instrumentation based on extremely reliable technologies but characterized by high costs. An alternative gas sensing technology is the electrochemical gas sensor which, even though having a lower accuracy, offers some advantages, such as low costs and high miniaturization. Among the gas sensors designed for air quality monitoring, the most interesting are the ones based on electrochemical cells. To operate such sensors, it is necessary to have an electronic circuit typically implemented on electronic boards provided by the sensor manufacturer. The research described in this document regards the design and implementation of an electronic board to support the operation of the “B” series of the electrochemical gas sensors produced by Alphasense. This brand provides electronic boards that, on one side, are capable of offering excellent performances, but on the other side, are characterized by some limitations, such as the possibility of using only one sensor at a time. The experimental activities of our laboratory in the field of real-time air quality monitoring by using low-cost devices and technologies demand electronic boards to support the operation of such sensors having a higher grade of flexibility. To overcome this and other limitations, a new electronic board has been designed and implemented. In this document, its design and the implementation details are described.

Hardware doi: 10.3390/hardware2020008

Authors: Henry Vennard Joshua M. Pearce David Denkenberger

A variety of events such as high-altitude electromagnetic pulses, extreme solar storms, and coordinated cyber attacks could result in a catastrophic loss of infrastructure on a continental or global scale. The lengthy repair of critical infrastructure creates a need for alternative fuels such as wood gas. Wood gas is produced by heating wood in a low-oxygen environment and can be used to power combustion engines. This work investigates a novel wood chipper, designed as an energy-efficient tool for producing wood gas stock, wood chips, aiming to speed up the transition to alternative fuel. A prototype is built and tested to determine the energy efficiency and production rate of the device. The results suggest that the wood chipper could produce one cord of wood chips, 3.6 m3, in less than a day and is a viable alternative to other manual wood-processing methods. In addition, the global scaling up of production of the wood chipper is considered, indicating that the mass production of the wood chipper could accelerate the transition of wood gas production methods from manual to machine-driven immediately after a catastrophic event.

Hardware doi: 10.3390/hardware2020007

Authors: Nicola Novello Mani Naiker Haydee Laza Kerry B. Walsh Sabine Tausz-Posch

Open-top chambers (OTCs) consist of semi-open enclosures used to investigate the impact of elevated carbon dioxide [CO2] on crops and larger plant communities. OTCs have lower operational costs than alternatives such as controlled environment cabinets and Free Air Carbon Dioxide Enrichment (FACE). A low-cost design is presented for an OTC with a surface area of 1.2 m2 and a target elevated CO2 concentration [CO2] of 650 µmol mol−1 adequate for trials involving cereals or grain legumes. The elevated CO2 chambers maintained an average concentration ± standard deviation of 652 ± 37 µmol mol−1 despite wind and air turbulences, in comparison to 407 ± 10 µmol mol−1 for non-enriched chambers. Relative to ambient (non-chamber) conditions, plants in the chambers were exposed to slightly warmer conditions (2.3 °C in daylight hours; 0.6 °C during night environment). The materials’ cost for constructing the chambers was USD 560 per chamber, while the CO2 control system for four chambers dedicated to CO2-enriched conditions cost USD 5388. To maintain the concentration of 650 µmol mol−1 during daylight hours, each chamber consumed 1.38 L min−1 of CO2. This means that a size G CO2 cylinder was consumed in 8–9 days in the operation of two chambers (at USD 40).

Hardware doi: 10.3390/hardware2020006

Authors: Edward Bednarz Alex Abad Jay Patel John Seasock

This study presents the design, build, and evaluation of a laboratory cam profile measuring machine tailored to demonstrate the mechanical principles and applications of various cam shapes. Utilizing a diverse set of cam profiles, the machine effectively converts rotational motion into measurable linear motion, achieving a range of motion profiles, including rising, declining, steady, and instantaneous actions. Key components of the machine include an angle gauge for precise rotational measurements and a linear dial indicator for accurately gauging the cam-induced displacement. This setup facilitates the measuring of displacement, and computation of velocity and acceleration for each cam shape, offering a dynamic visual and numerical aid for engineering and design.

Hardware doi: 10.3390/hardware2020005

Authors: Francesco P. Chietera

Additive manufacturing has emerged as a transformative methodology in numerous engineering domains, with the fabrication of antennas and electromagnetic devices being a promising application area. This study presents a comprehensive review of the application of these technologies for manufacturing electromagnetic devices, offering a categorized analysis based on different types of additive manufacturing techniques. Each category is examined, and its characteristics are briefly described, highlighting not only the most innovative and significant devices fabricated using specific technologies, but also identifying their limitations and strengths. Through a dual analysis, this paper provides a deep understanding of the potential of and challenges associated with using different additive manufacturing technologies in the design and crafting of electromagnetic components. Moreover, this review offers recommendations for future studies, suggesting how the unique features of this new manufacturing paradigm could be further leveraged for breakthroughs in the electromagnetic field.

Hardware doi: 10.3390/hardware2020004

Authors: Julie Lemesle Maxence Bigerelle

A new instrument using reflectance transformation imaging (RTI), named MorphoLight, has been developed for surface characterization. This instrument is designed to be adjustable to surfaces, ergonomic, and uses a combination of high-resolution imaging functions, i.e., focus stacking (FS) and high dynamic range (HDR), to improve the image quality. A topographical analysis method is proposed with the instrument. This method is an improvement of the surface gradient characterization by light reflectance (SGCLR) method. This aims to analyze slope/curvature maps, traditionally studied in RTI, but also to find the most relevant lighting position and 3D surface parameter which highlight morphological signatures on surfaces and/or discriminate surfaces. RTI measurements and analyses are performed on two zones, sky and sea, of a naval painting which have the same color palette but different painting strokes. From the statistical analysis using bootstrapping and analysis of variance (ANOVA), it is highlighted that the high-resolution images (stacked and tonemapped from HDR images) improve the image quality and make it possible to better see a difference between both painting zones. This difference is highlighted by the fractal dimension for a lighting position (θ, φ) = (30°, 225°); the fractal dimension of the sea part is higher because of the presence of larger brushstrokes and painting heaps.

Hardware doi: 10.3390/hardware2010003

Authors: Moe Kuriyama Toshio Takayama

Soft actuators, designed for fragile item conveyance and navigation in complex environments, have garnered recent attention. This study proposes a cost-effective soft actuator, created by weaving tubes into twill patterns, capable of transportation and movement. The actuator achieves this by inducing traveling waves on its upper and lower surfaces through sequential pressurization of tubes. Notably, its fabrication does not require specialized molds, contributing to cost efficiency. The single actuator generates traveling waves with two degrees of freedom. Conventional silicone tube-based actuators demonstrate slow transport speeds (3.5 mm/s). To address this, this study replaced silicone tubes with pneumatic artificial muscles, enhancing overall body deformation and actuator speed. Experiments involving both extensional and contractional artificial muscles demonstrated that soft actuators with extensional artificial muscles significantly improved transportation and movement speed to 8.0 mm/s.

Hardware doi: 10.3390/hardware2010002

Authors: Morgan C. Woods Nathan Nauta Joshua M. Pearce

Alternative food sources are essential in both low-resource settings and during emergencies like abrupt sunlight reduction scenarios. Seaweed presents a promising option but requires investigation into the viability of unconventionally sourced ropes for harvesting. In this regard, a low-cost reliable method to test the tensile strength of rope is needed to validate alternative materials for use in harvesting seaweed. Commercial rope testing jigs alone range in price from several thousand to tens of thousands of dollars, so there is interest in developing a lower-cost alternative. Addressing these needs, this article reports on an open-source design for tensile strength rope testing hardware. The hardware design focuses on using readily available parts that can be both sourced from a hardware store and manufactured with simple tools to provide the greatest geographic accessibility. The jig design, which can be fabricated for CAD 20, is two to three orders of magnitude less expensive than commercially available solutions. The jig was built and tested using a case study example investigating denim materials (of 1 5/8”, 3 1/4”, 4 7/8”, 6 1/2”, and 8 1/8” widths) as a potential alternative rope material for seaweed farming. Denim demonstrated strengths of up to 1.65 kN for the widest sample, and the jig demonstrated sufficient strength and stiffness for operations at forces below 4 kN. The results are discussed and areas for future improvements are outlined to adapt the device to other circumstances and increase the strength of materials that can be tested.

Hardware doi: 10.3390/hardware2010001

Authors: Neil Lin Maryse Gagnon Kevin Y. Wu

Three-dimensional (3D) printing is a process in which materials are added together in a layer-by-layer manner to construct customized products. Many different techniques of 3D printing exist, which vary in materials used, cost, advantages, and drawbacks. Medicine is increasingly benefiting from this transformative technology, and the field of ophthalmology is no exception. The possible 3D printing applications in eyecare are vast and have been explored in the literature, such as 3D-printed ocular prosthetics, orbital implants, educational and anatomical models, as well as surgical planning and training. Novel drug-delivery platforms have also emerged because of 3D printing, offering improved treatment modalities for several ocular pathologies. Innovative research in 3D bioprinting of viable tissues, including the cornea, retina, and conjunctiva, is presenting an avenue for regenerative ophthalmic therapies in the future. Although further development in printing capabilities and suitable materials is required, 3D printing represents a powerful tool for enhancing eye health.

Hardware doi: 10.3390/hardware1010005

Authors: Daniel Pascal Hausherr Dirk Berben

Internet of Things (IoT) applications based on the single-board computer Raspberry Pi depend on reliable and sufficiently powerful energy systems to allow system diversity, flexibility, and available computing power. On this account, we developed an all-in-one module to simplify both the autonomous and network-wired power supply of Raspberry Pi-based systems. The module generates a stable voltage of 5.1 VDC with an available maximum current of 3 A to power a single Raspberry Pi model 3B+ or 4 and furthermore provides an additional power source of 3 VDC–12 VDC at a maximum of 3 A for use by arbitrary peripherals. To accommodate different use cases, the system has various energy supply options such as a 4S lithium polymer (LiPo) battery for autonomous operation, including a battery management and charging solution, as well as wire-based options, such as USB-C with USB Power Delivery (USB-PD) or Power over Ethernet (PoE+) via an additional module.

Hardware doi: 10.3390/hardware1010004

Authors: Matheus C. Carvalho Joanne M. Oakes

Compound-specific isotope analysis (CSIA) can provide unique insights into the cycling of elements including carbon and nitrogen. One approach for CSIA is the use of high-performance liquid chromatography (HPLC) to separate compounds of interest, followed by analysis of these compounds using an elemental analyser coupled to an isotope ratio mass spectrometer. A key component of this technique is the fraction collector, which automatically collects compounds as they are separated by HPLC. Here, we present a fraction collector that is a simple adaptation of a 3D printer, and, thus, can be easily adopted by any laboratory already equipped for HPLC. In addition to the much lower cost compared to commercial alternatives, this adaptation has the advantage for CSIA that the 3D printer is able to heat the collected fractions, which is not true for many commercial fraction collectors. Heating allows faster evaporation of the solvent, so that the dried compounds can be measured by EA–IRMS immediately. The procedure can be repeated consecutively so that diluted solutions can have the compounds concentrated for analysis. Any computer-controlled HPLC can be integrated to the fraction collector used here by means of AutoIt.

Hardware doi: 10.3390/hardware1010003

Authors: Ling Kong Wenjie Lv Haijing He Yibo Yuan Libin Du

Semiconductor lasers have garnered significant prominence in diverse domains, including fiber optic communication and precision measurement, owing to their remarkable attributes such as compact size, lightweight construction, broad wavelength range, and tunability. Among these lasers, tunable semiconductor lasers assume a pivotal role in fiber Bragg grating demodulation systems, as the stability of their output wavelength and power directly influences the overall performance of the demodulation system. Ensuring the steadfastness of the output power and emission wavelength necessitates the provision of a stable driving current and the maintenance of a consistent operating temperature. Consequently, a specialized driver circuit necessitates meticulous design and implementation. In this investigation, a novel STM32 microcontroller-based tunable laser control circuit was meticulously developed to meet the practical requisites of fiber Bragg grating sensor demodulation. Leveraging the advanced capabilities of the MAX5113 current control chip and the MAX1978 temperature control chip, a dedicated circuit for constant current driving and temperature regulation of the tunable semiconductor laser was meticulously devised. Additionally, the design incorporates cutting-edge components, including a photodetector and an ADC conversion module, to seamlessly fulfill the intricate demands of the fiber Bragg grating demodulation system. The conclusive experimental results conclusively demonstrate the excellent stability of the output current produced by the constant current driving circuit, the minimal fluctuations observed in laser temperature, and the remarkable tunability of the laser’s output wavelength within the precise range of 1525 to 1550 nm. Notably, the wavelength fluctuations are confined to an impressively narrow margin of just 3 pm, providing definitive evidence that the design fully satisfies the practical requirements.

Hardware doi: 10.3390/hardware1010002

Authors: Liliane Auwerter

The development of new hardware has never been as accessible as it is today [...]

Hardware doi: 10.3390/hardware1010001

Authors: Peter C. Hauser

Hardware (ISSN 2813-6640) [...]