Hardware

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. Full article

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. Full article

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. Full article

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. Full article

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. Full article

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. Full article

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. Full article

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). Full article

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. Full article

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. Full article

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. Full article

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. Full article

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. Full article

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. Full article

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. Full article

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. Full article

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. Full article