Pub Date : 2025-07-25DOI: 10.1016/j.ohx.2025.e00670
Laurens Parret , Kenneth Simoens , Jo De Vrieze , Ilse Smets
The BIO-SPEC is an open-source, cost-effective, and modular bench-top bioreactor system designed for batch, sequencing batch, and chemostat cultivation. Featuring thermoelectric condensers to eliminate the need for a chiller, it ensures stable long-term operation. Controlled by a Raspberry Pi, the BIO-SPEC offers flexibility in headplate design, gas supply, and feeding strategies, making it a versatile alternative to high-cost commercial systems. This paper details the design, construction, and validation of the BIO-SPEC system, demonstrating its potential to advance microbiology and bioprocessing research through accessible and reliable hardware at a fraction of the cost of commercial systems.
{"title":"BIO-SPEC: An open-source bench-top parallel bioreactor system","authors":"Laurens Parret , Kenneth Simoens , Jo De Vrieze , Ilse Smets","doi":"10.1016/j.ohx.2025.e00670","DOIUrl":"10.1016/j.ohx.2025.e00670","url":null,"abstract":"<div><div>The BIO-SPEC is an open-source, cost-effective, and modular bench-top bioreactor system designed for batch, sequencing batch, and chemostat cultivation. Featuring thermoelectric condensers to eliminate the need for a chiller, it ensures stable long-term operation. Controlled by a Raspberry Pi, the BIO-SPEC offers flexibility in headplate design, gas supply, and feeding strategies, making it a versatile alternative to high-cost commercial systems. This paper details the design, construction, and validation of the BIO-SPEC system, demonstrating its potential to advance microbiology and bioprocessing research through accessible and reliable hardware at a fraction of the cost of commercial systems.</div></div>","PeriodicalId":37503,"journal":{"name":"HardwareX","volume":"23 ","pages":"Article e00670"},"PeriodicalIF":2.1,"publicationDate":"2025-07-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144763708","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
In this paper we present the design, construction and performance of a self-contained float-controlled water level gauge for monitoring water levels in streams and small rivers. This device is inexpensive (cost of about EUR 220), easy to build (no electronics skills or specialized tools required; assembled in a few hours) and straightforward to use. The gauge remains autonomously operational for several weeks in remote locations without the need for an external power supply or solar panel and in the harsh tropical climatic conditions. Data can be downloaded wirelessly in the field using an Android smartphone or tablet. This gauge is capable of a measurement precision of ±1 mm at temperatures ranging from 20 to 30 °C and accurate to within 2 mm of manual readings in a controlled laboratory environment. In the field, the mean absolute error (MAE) of measurements taken with the water level gauge compared to that obtained with the OTT-SE200 − a commercial float-controlled angle encoder water level gauge − over a full tropical rainy season and for a measurement range of 0.5 m, was 2.6 mm (n = 8,017).
本文介绍了一种用于监测溪流和小河水位的独立浮子控制水位计的设计、构造和性能。该设备价格低廉（成本约220欧元），易于构建(不需要电子技术或专门工具；组装在几个小时内)和直接使用。在偏远地区，在恶劣的热带气候条件下，该仪表可以在不需要外部电源或太阳能电池板的情况下自主运行数周。数据可以在现场用安卓智能手机或平板电脑无线下载。该仪表能够在20至30°C的温度范围内测量精度为±1毫米，并在受控的实验室环境中精确到手动读数的2毫米以内。在现场，在整个热带雨季，测量范围为0.5 m时，与商用浮子控制角度编码器水位计ot - se200相比，使用该水位计测量的平均绝对误差（MAE）为2.6 mm （n = 8,017）。
{"title":"A float-controlled self-contained laser gauge for monitoring river levels in tropical environments","authors":"Alain Pierret , Norbert Silvera , Keo Oudone Latsachack , Khampasith Chanthavong , Phabvilay Sounyafong , Olivier Ribolzi","doi":"10.1016/j.ohx.2025.e00682","DOIUrl":"10.1016/j.ohx.2025.e00682","url":null,"abstract":"<div><div>In this paper we present the design, construction and performance of a self-contained float-controlled water level gauge for monitoring water levels in streams and small rivers. This device is inexpensive (cost of about EUR 220), easy to build (no electronics skills or specialized tools required; assembled in a few hours) and straightforward to use. The gauge remains autonomously operational for several weeks in remote locations without the need for an external power supply or solar panel and in the harsh tropical climatic conditions. Data can be downloaded wirelessly in the field using an Android smartphone or tablet. This gauge is capable of a measurement precision of ±1 mm at temperatures ranging from 20 to 30 °C and accurate to within 2 mm of manual readings in a controlled laboratory environment. In the field, the mean absolute error (MAE) of measurements taken with the water level gauge compared to that obtained with the OTT-SE200 − a commercial float-controlled angle encoder water level gauge − over a full tropical rainy season and for a measurement range of 0.5 m, was 2.6 mm (n = 8,017).</div></div>","PeriodicalId":37503,"journal":{"name":"HardwareX","volume":"23 ","pages":"Article e00682"},"PeriodicalIF":2.0,"publicationDate":"2025-07-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144711421","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-07-22DOI: 10.1016/j.ohx.2025.e00672
Franco Alessandro Arenas Mamani , Gustavo Bryam Capira Malcoaccha , Marco Antonio Blanco Quicaño , Leonardo Gabriel Prado Gutierrez , German Alberto Echaiz Espinoza , Erasmo Sulla Espinoza , Andres Ortiz Salazar
This article details the design, assembly, and tuning of a multipurpose FPV (First Person View) drone designed as a budget-friendly and customizable alternative to professional-grade drone model. Built with a focus on performance, adaptability, durability, and ease of repair, the APdrone (All Purpose Drone) incorporates high-quality components such as a carbon fiber frame, brushless motors, and advanced flight controllers. To ensure optimal flight characteristics, a comprehensive tuning process was performed using empirical adjustments, supported by controlled testing environments, to optimize PID parameters (, , ) to achieve stable and precise flight performance. Testing demonstrated a flight time of approximately 8 min under standard conditions with a maximum payload capacity of 0.98 kg. Importantly, the APdrone offers operational flexibility and significant cost savings (USD 647.09), compared to high-end drones like the DJI Mavic 3 Pro, while maintaining comparable functionality and allowing for customization. To encourage accessibility, reproducibility and further development, open-source design files, including CAD schematics, firmware configurations, and assembly instructions, are provided. The APdrone serves as a scalable platform for research, recreational use, and advancements within the UAV (Unmanned Aerial Vehicle) field.
本文详细介绍了多用途FPV（第一人称视角）无人机的设计，组装和调整，该无人机设计为预算友好且可定制的专业级无人机模型替代方案。APdrone （All Purpose Drone）专注于性能、适应性、耐用性和易于维修，采用了高质量的部件，如碳纤维框架、无刷电机和先进的飞行控制器。为了确保最优的飞行特性，在受控测试环境的支持下，利用经验调整进行了全面的整定过程，以优化PID参数（Kp, Ki, Kd），以实现稳定和精确的飞行性能。测试表明，在标准条件下飞行时间约为8分钟，最大有效载荷能力为0.98千克。重要的是，与DJI Mavic 3 Pro等高端无人机相比，APdrone提供了操作灵活性和显著的成本节约（647.09美元），同时保持了相当的功能并允许定制。为了鼓励可访问性、可重复性和进一步的开发，提供了开源设计文件，包括CAD原理图、固件配置和组装说明。APdrone作为一个可扩展的平台，用于无人机（UAV）领域的研究、娱乐和进步。
{"title":"Design, assembly, and tuning of a multipurpose FPV drone: A flexible and low-cost alternative","authors":"Franco Alessandro Arenas Mamani , Gustavo Bryam Capira Malcoaccha , Marco Antonio Blanco Quicaño , Leonardo Gabriel Prado Gutierrez , German Alberto Echaiz Espinoza , Erasmo Sulla Espinoza , Andres Ortiz Salazar","doi":"10.1016/j.ohx.2025.e00672","DOIUrl":"10.1016/j.ohx.2025.e00672","url":null,"abstract":"<div><div>This article details the design, assembly, and tuning of a multipurpose FPV (First Person View) drone designed as a budget-friendly and customizable alternative to professional-grade drone model. Built with a focus on performance, adaptability, durability, and ease of repair, the <em>APdrone</em> (All Purpose Drone) incorporates high-quality components such as a carbon fiber frame, brushless motors, and advanced flight controllers. To ensure optimal flight characteristics, a comprehensive tuning process was performed using empirical adjustments, supported by controlled testing environments, to optimize PID parameters (<span><math><msub><mrow><mi>K</mi></mrow><mrow><mi>p</mi></mrow></msub></math></span>, <span><math><msub><mrow><mi>K</mi></mrow><mrow><mi>i</mi></mrow></msub></math></span>, <span><math><msub><mrow><mi>K</mi></mrow><mrow><mi>d</mi></mrow></msub></math></span>) to achieve stable and precise flight performance. Testing demonstrated a flight time of approximately 8 min under standard conditions with a maximum payload capacity of 0.98 kg. Importantly, the <em>APdrone</em> offers operational flexibility and significant cost savings (USD 647.09), compared to high-end drones like the DJI Mavic 3 Pro, while maintaining comparable functionality and allowing for customization. To encourage accessibility, reproducibility and further development, open-source design files, including CAD schematics, firmware configurations, and assembly instructions, are provided. The <em>APdrone</em> serves as a scalable platform for research, recreational use, and advancements within the UAV (Unmanned Aerial Vehicle) field.</div></div>","PeriodicalId":37503,"journal":{"name":"HardwareX","volume":"23 ","pages":"Article e00672"},"PeriodicalIF":2.1,"publicationDate":"2025-07-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144724949","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Ultrasound (US) is a widely popular imaging technique for the diagnosis of tumors and associated soft tissue pathology. Traditionally, excised tumor masses are manually sliced for microscopic examination, which is a resource-intensive, time-consuming process, and prone to human error. The proposed work addresses these challenges by developing a cost-effective US gantry system integrated with a deep learning algorithm to automate the tissue slice selection process. This system scans the entire tumor and by integrating a deep learning algorithm predicts the optimal slice to assist its preparation for microscopic analysis. Automating this process reduces the time and resources required while minimizing the risk of human error. Optimal tissue slice reduces sampling associated uncertainty in diagnosis and treatment planning. Thereby determining tumor grade and type, and helping to reduce the treatment risks. The initial development focused on a linear US gantry that moves in one direction to acquire B-mode images. However, this design is limited, as it cannot fully capture the tumor’s structural complexity. In order to overcome this, we developed an angular US gantry that can maneuver along multiple angles, acquiring a broader range of images for comprehensive geometric analysis. The angular gantry demonstrated significant improvement, achieving 98% accuracy in selecting the optimal tissue slice.
{"title":"Design and implementation of a low-cost gimbal-based angular ultrasound gantry for optimal tissue slice selection using deep learning","authors":"Abhishek Kumar, Akshay S. Menon, Divyansh Sharma, Raviteja Sista, Debdoot Sheet","doi":"10.1016/j.ohx.2025.e00676","DOIUrl":"10.1016/j.ohx.2025.e00676","url":null,"abstract":"<div><div>Ultrasound (US) is a widely popular imaging technique for the diagnosis of tumors and associated soft tissue pathology. Traditionally, excised tumor masses are manually sliced for microscopic examination, which is a resource-intensive, time-consuming process, and prone to human error. The proposed work addresses these challenges by developing a cost-effective US gantry system integrated with a deep learning algorithm to automate the tissue slice selection process. This system scans the entire tumor and by integrating a deep learning algorithm predicts the optimal slice to assist its preparation for microscopic analysis. Automating this process reduces the time and resources required while minimizing the risk of human error. Optimal tissue slice reduces sampling associated uncertainty in diagnosis and treatment planning. Thereby determining tumor grade and type, and helping to reduce the treatment risks. The initial development focused on a linear US gantry that moves in one direction to acquire B-mode images. However, this design is limited, as it cannot fully capture the tumor’s structural complexity. In order to overcome this, we developed an angular US gantry that can maneuver along multiple angles, acquiring a broader range of images for comprehensive geometric analysis. The angular gantry demonstrated significant improvement, achieving 98% accuracy in selecting the optimal tissue slice.</div></div>","PeriodicalId":37503,"journal":{"name":"HardwareX","volume":"23 ","pages":"Article e00676"},"PeriodicalIF":2.0,"publicationDate":"2025-07-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144685747","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-07-18DOI: 10.1016/j.ohx.2025.e00683
Veronika Wohlmuthova, Michal Labuda, Mariana Benova
Magnetic fields play a crucial role in modern science and technology - yet precise and accessible tools for their measurement remain limited, especially for small laboratories, educators, or independent researchers. This paper introduces a novel, open-source magnetic field measurement system based on three-axis sensors for monitoring both direct and extremely low frequency magnetic fields. The device features a modular hardware design centered around a custom PCB, enabling flexible analog filtering, Bluetooth data transmission, and offline LCD visualization. By combining the MC858 and MPU9250 sensors with precise analog signal conditioning and a 12-bit ADC, the system ensures reliable detection of magnetic fields including the 50 Hz mains frequency and its harmonics. To verify the functionality of the device, experimental measurements were conducted inside a Faraday cage using a common hair dryer placed at distances of 1 cm and 3 cm from the sensors as a source of electromagnetic field. Frequency analysis confirmed reliable detection of the dominant 50 Hz component and its harmonics, as well as the system’s ability to distinguish changes in field intensity based on distance and operating state of the source device.
{"title":"A low-cost portable system for 3-Axis measurement of static and extremely low frequency magnetic fields","authors":"Veronika Wohlmuthova, Michal Labuda, Mariana Benova","doi":"10.1016/j.ohx.2025.e00683","DOIUrl":"10.1016/j.ohx.2025.e00683","url":null,"abstract":"<div><div>Magnetic fields play a crucial role in modern science and technology - yet precise and accessible tools for their measurement remain limited, especially for small laboratories, educators, or independent researchers. This paper introduces a novel, open-source magnetic field measurement system based on three-axis sensors for monitoring both direct and extremely low frequency magnetic fields. The device features a modular hardware design centered around a custom PCB, enabling flexible analog filtering, Bluetooth data transmission, and offline LCD visualization. By combining the MC858 and MPU9250 sensors with precise analog signal conditioning and a 12-bit ADC, the system ensures reliable detection of magnetic fields including the 50 Hz mains frequency and its harmonics. To verify the functionality of the device, experimental measurements were conducted inside a Faraday cage using a common hair dryer placed at distances of 1 cm and 3 cm from the sensors as a source of electromagnetic field. Frequency analysis confirmed reliable detection of the dominant 50 Hz component and its harmonics, as well as the system’s ability to distinguish changes in field intensity based on distance and operating state of the source device.</div></div>","PeriodicalId":37503,"journal":{"name":"HardwareX","volume":"23 ","pages":"Article e00683"},"PeriodicalIF":2.0,"publicationDate":"2025-07-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144696905","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-07-17DOI: 10.1016/j.ohx.2025.e00679
Minh Nhat Huynh , Quoc Minh Lam , Cong Toai Truong , Huy Hung Nguyen , Van Tu Duong
Rapid advancements in energy storage technology spurred by the use of electricity in a variety of applications have brought attention to the critical need for precise battery capacity evaluation. The electronic DC load devices play an important role in those tests by replicating real-world discharge conditions. However, commercial DC load systems are often prohibitively expensive and remain largely inaccessible to small enterprises, academic laboratories, and independent researchers. While open-source alternatives offer cost advantages, many existing designs lack scalability, flexibility, and ease of use. This study proposes a low-cost, modular electronic DC load capable of continuous operation at up to per module. With its user-friendly interface and support for numerous other tests, including constant current, constant resistor, constant power, battery evaluation, and high-power pulse charge (HPPC) the proposed electronic DC load is robust and simple to use for battery research and evaluation.
{"title":"Low-cost electronic DC load module design for battery capacity evaluation","authors":"Minh Nhat Huynh , Quoc Minh Lam , Cong Toai Truong , Huy Hung Nguyen , Van Tu Duong","doi":"10.1016/j.ohx.2025.e00679","DOIUrl":"10.1016/j.ohx.2025.e00679","url":null,"abstract":"<div><div>Rapid advancements in energy storage technology spurred by the use of electricity in a variety of applications have brought attention to the critical need for precise battery capacity evaluation. The electronic DC load devices play an important role in those tests by replicating real-world discharge conditions. However, commercial DC load systems are often prohibitively expensive and remain largely inaccessible to small enterprises, academic laboratories, and independent researchers. While open-source alternatives offer cost advantages, many existing designs lack scalability, flexibility, and ease of use. This study proposes a low-cost, modular electronic DC load capable of continuous operation at up to <span><math><mrow><mn>50</mn><mi>W</mi></mrow></math></span> per module. With its user-friendly interface and support for numerous other tests, including constant current, constant resistor, constant power, battery evaluation, and high-power pulse charge (HPPC) the proposed electronic DC load is robust and simple to use for battery research and evaluation.</div></div>","PeriodicalId":37503,"journal":{"name":"HardwareX","volume":"23 ","pages":"Article e00679"},"PeriodicalIF":2.0,"publicationDate":"2025-07-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144670577","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-07-16DOI: 10.1016/j.ohx.2025.e00674
Montana Ligman, Kioumars A. Rezaie, Ramya Shah, Chris Keeter, Bryson Sutterfield, Mirjam Fürth
We introduce an enhanced iteration of OpenFish, a previously developed open-source soft robotic fish. The original model, developed at Delft University of Technology, successfully emulated thunniform swimming through a unique propulsion system utilizing both active and passive tail segments. This design aimed to optimize speed and efficiency while fostering future advancements in soft robotic fish research. To further enhance OpenFish, we undertook a redesign process, making modifications to the fish hull and internal components. These changes aimed to simplify construction, address waterproofing issues, and facilitate the development of an autonomous version of the fish. Our work encompasses an updated description of the construction process, customization options, and detailed insights into hardware implementation, including waterproofing techniques for the soft robotic fish.
{"title":"Fluid interaction study: Hydrodynamic robot (FISHR) — Expansion of bioinspired soft robotic fish","authors":"Montana Ligman, Kioumars A. Rezaie, Ramya Shah, Chris Keeter, Bryson Sutterfield, Mirjam Fürth","doi":"10.1016/j.ohx.2025.e00674","DOIUrl":"10.1016/j.ohx.2025.e00674","url":null,"abstract":"<div><div>We introduce an enhanced iteration of OpenFish, a previously developed open-source soft robotic fish. The original model, developed at Delft University of Technology, successfully emulated thunniform swimming through a unique propulsion system utilizing both active and passive tail segments. This design aimed to optimize speed and efficiency while fostering future advancements in soft robotic fish research. To further enhance OpenFish, we undertook a redesign process, making modifications to the fish hull and internal components. These changes aimed to simplify construction, address waterproofing issues, and facilitate the development of an autonomous version of the fish. Our work encompasses an updated description of the construction process, customization options, and detailed insights into hardware implementation, including waterproofing techniques for the soft robotic fish.</div></div>","PeriodicalId":37503,"journal":{"name":"HardwareX","volume":"23 ","pages":"Article e00674"},"PeriodicalIF":2.1,"publicationDate":"2025-07-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144739503","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-07-13DOI: 10.1016/j.ohx.2025.e00678
Floriberto Díaz-Díaz , Prisciliano Felipe de Jesús Cano-Barrita
This paper presents the design and construction of a cost-effective embeddable nuclear magnetic resonance sensor using 3D printing to improve the construction process. The sensor comprises two 25.4 mm diameter x 3 mm thick neodymium-iron-boron disk magnets and an elliptical radio frequency coil. Magnetic field simulations were employed to determine the optimal separation between magnets, achieving a relatively homogeneous B0 field of 180 mT at the center of the array. Custom 3D-printed parts ensured precise magnet alignment and facilitated coil fabrication. The sensor was encased within a Faraday cage constructed from a printed circuit board to mitigate external electromagnetic interference. A remote tuning circuit was developed to tune the coil to 7.66 MHz. Initial testing involved using an eraser sample to determine the required 90° and 180° pulse amplitudes and duration. The sensor’s performance was further validated under immersion conditions in milk, yogurt, and fresh cement paste, using the Carr-Purcell-Meiboom-Gill technique. The signals obtained were processed by fitting the data to an exponential decay function to obtain the T2 lifetimes and their corresponding signal intensities, and by Inverse Laplace Transformation to obtain the T2 lifetime distribution. Results indicate the sensoŕs capability to detect variations in samples having different compositions.
{"title":"Design and construction of a small embeddable nuclear magnetic resonance sensor utilizing 3D-printed components","authors":"Floriberto Díaz-Díaz , Prisciliano Felipe de Jesús Cano-Barrita","doi":"10.1016/j.ohx.2025.e00678","DOIUrl":"10.1016/j.ohx.2025.e00678","url":null,"abstract":"<div><div>This paper presents the design and construction of a cost-effective embeddable nuclear magnetic resonance sensor using 3D printing to improve the construction process. The sensor comprises two 25.4 mm diameter x 3 mm thick neodymium-iron-boron disk magnets and an elliptical radio frequency coil. Magnetic field simulations were employed to determine the optimal separation between magnets, achieving a relatively homogeneous B<sub>0</sub> field of 180 mT at the center of the array. Custom 3D-printed parts ensured precise magnet alignment and facilitated coil fabrication. The sensor was encased within a Faraday cage constructed from a printed circuit board to mitigate external electromagnetic interference. A remote tuning circuit was developed to tune the coil to 7.66 MHz. Initial testing involved using an eraser sample to determine the required 90° and 180° pulse amplitudes and duration. The sensor’s performance was further validated under immersion conditions in milk, yogurt, and fresh cement paste, using the Carr-Purcell-Meiboom-Gill technique. The signals obtained were processed by fitting the data to an exponential decay function to obtain the T<sub>2</sub> lifetimes and their corresponding signal intensities, and by Inverse Laplace Transformation to obtain the T<sub>2</sub> lifetime distribution. Results indicate the sensoŕs capability to detect variations in samples having different compositions.</div></div>","PeriodicalId":37503,"journal":{"name":"HardwareX","volume":"23 ","pages":"Article e00678"},"PeriodicalIF":2.0,"publicationDate":"2025-07-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144654756","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-07-12DOI: 10.1016/j.ohx.2025.e00677
Xavier Cano-Ferrer , Marcelo J. Moglie , George Konstantinou , Antonin Blot , Gaia Bianchini , Albane Imbert , Petr Znamenskiy , M. Florencia Iacaruso
Presenting visual stimuli in neuroscience experiments often requires precise temporal alignment between visual events and electrophysiological or behavioural recordings. This is typically achieved by combining analogue signals that convey timing information about the visual cue shown on liquid crystal displays (LCDs), sensed via photodetectors and recorded through analogue-to-digital converter (ADC) acquisition boards. However, most commercial photodetector systems pose limitations such as high voltage requirements, large sensor footprints that interfere with stimulus presentation, and limited compatibility with open-source platforms. Here, we present a compact, low-cost photodetector system designed for compatibility with common 3.3–5 V microcontroller-based development boards (e.g., Arduino) and the open-source visual programming language Bonsai, widely used in neuroscience for experiment control. The circuit consists of a photodiode, an amplification stage, and a low-pass filter, and can optionally incorporate an infrared filter—useful for experiments involving infrared touch displays. To facilitate reproducibility, we provide complete design files, a bill of materials and detailed building and operational instructions. We further introduce a four-channel variant, enabling the detection of four-bit binary signals for more complex synchronization needs. Validation and characterization of the device were performed through grayscale gamma correction analysis of LCD monitors using Bonsai. Additionally, we demonstrate the system’s utility in a head-fixed mouse experiment, synchronizing visual stimulus onset with neuronal recordings acquired via Neuropixels 2.0 probes. Performance comparisons with a commercial photodetector device indicate that our system achieves equivalent signal fidelity at a substantially lower cost, while maintaining a minimal footprint suitable for experimental use.
{"title":"PhotoNeuro: A compact photodetector for synchronization of visual stimulus presentation during behavioural experiments in neuroscience","authors":"Xavier Cano-Ferrer , Marcelo J. Moglie , George Konstantinou , Antonin Blot , Gaia Bianchini , Albane Imbert , Petr Znamenskiy , M. Florencia Iacaruso","doi":"10.1016/j.ohx.2025.e00677","DOIUrl":"10.1016/j.ohx.2025.e00677","url":null,"abstract":"<div><div>Presenting visual stimuli in neuroscience experiments often requires precise temporal alignment between visual events and electrophysiological or behavioural recordings. This is typically achieved by combining analogue signals that convey timing information about the visual cue shown on liquid crystal displays (LCDs), sensed via photodetectors and recorded through analogue-to-digital converter (ADC) acquisition boards. However, most commercial photodetector systems pose limitations such as high voltage requirements, large sensor footprints that interfere with stimulus presentation, and limited compatibility with open-source platforms. Here, we present a compact, low-cost photodetector system designed for compatibility with common 3.3–5 V microcontroller-based development boards (e.g., Arduino) and the open-source visual programming language Bonsai, widely used in neuroscience for experiment control. The circuit consists of a photodiode, an amplification stage, and a low-pass filter, and can optionally incorporate an infrared filter—useful for experiments involving infrared touch displays. To facilitate reproducibility, we provide complete design files, a bill of materials and detailed building and operational instructions. We further introduce a four-channel variant, enabling the detection of four-bit binary signals for more complex synchronization needs. Validation and characterization of the device were performed through grayscale gamma correction analysis of LCD monitors using Bonsai. Additionally, we demonstrate the system’s utility in a head-fixed mouse experiment, synchronizing visual stimulus onset with neuronal recordings acquired via Neuropixels 2.0 probes. Performance comparisons with a commercial photodetector device indicate that our system achieves equivalent signal fidelity at a substantially lower cost, while maintaining a minimal footprint suitable for experimental use.</div></div>","PeriodicalId":37503,"journal":{"name":"HardwareX","volume":"23 ","pages":"Article e00677"},"PeriodicalIF":2.0,"publicationDate":"2025-07-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144670576","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-07-09DOI: 10.1016/j.ohx.2025.e00667
Fausto Andrés Escobar , Carlos Felipe Rengifo , Víctor Hugo Mosquera
This study proposes an electrical impedance tomography (EIT) device based on a programmable system on a chip (PSoc). The EIT-PSoC system is implemented using two PSoC 5LP platforms. A resistive phantom is used to study frame frequency (fps), accuracy (Ac), and signal-to-noise ratio (SNR). A saline phantom, along with both conductive and non-conductive objects, is employed to evaluate the system’s ability to detect changes in impedance distribution. Finally, the dielectric characteristics of the human lower pelvis is emulated using four agar phantoms, allowing an evaluation of the EIT-PSoC system’s performance in response to changes in fluid volume and conductivity. Experiments conducted on the resistive phantom to characterize the EIT-PSoC system demonstrate a frame frequency of 100 fps, a median SNR of 63.59 dB, and an accuracy of 95.39% when using a 0.98 mA sinusoidal current signal at 50 kHz. EIT image reconstruction shows that the proposed system can distinguish impedance changes in the saline phantom. Additionally, by utilizing the global impedance (GI) index and the agar phantoms, the EIT-PSoC system can detect changes in volume and conductivity, making this system a promising alternative for monitoring the volume and conductivity of biological fluids.
{"title":"Eight-channel high-speed electrical impedance tomography device implemented on a programmable system on a chip","authors":"Fausto Andrés Escobar , Carlos Felipe Rengifo , Víctor Hugo Mosquera","doi":"10.1016/j.ohx.2025.e00667","DOIUrl":"10.1016/j.ohx.2025.e00667","url":null,"abstract":"<div><div>This study proposes an electrical impedance tomography (EIT) device based on a programmable system on a chip (PSoc). The EIT-PSoC system is implemented using two PSoC 5LP platforms. A resistive phantom is used to study frame frequency (fps), accuracy (Ac), and signal-to-noise ratio (SNR). A saline phantom, along with both conductive and non-conductive objects, is employed to evaluate the system’s ability to detect changes in impedance distribution. Finally, the dielectric characteristics of the human lower pelvis is emulated using four agar phantoms, allowing an evaluation of the EIT-PSoC system’s performance in response to changes in fluid volume and conductivity. Experiments conducted on the resistive phantom to characterize the EIT-PSoC system demonstrate a frame frequency of 100 fps, a median SNR of 63.59 dB, and an accuracy of 95.39% when using a 0.98 mA sinusoidal current signal at 50 kHz. EIT image reconstruction shows that the proposed system can distinguish impedance changes in the saline phantom. Additionally, by utilizing the global impedance (GI) index and the agar phantoms, the EIT-PSoC system can detect changes in volume and conductivity, making this system a promising alternative for monitoring the volume and conductivity of biological fluids.</div></div>","PeriodicalId":37503,"journal":{"name":"HardwareX","volume":"23 ","pages":"Article e00667"},"PeriodicalIF":2.0,"publicationDate":"2025-07-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144632309","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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