The conceptual shift is subtle but consequential. Conventional electrophoretic mobility shift assays, or EMSA, are designed to freeze the molecular population distribution established in bulk solution before loading. Association is suppressed by dilution or competitor molecules, dissociation is reduced by lowering temperature or chemical stabilization, and the gel is treated as kinetically silent. The assumption is that the population distribution prepared before loading remains unchanged during the 10 to 20 minutes required for sample entry into the gel and subsequent migration. In practice, Saha and Fraden note, that assumption is often difficult to justify, particularly when the gel is operated at a temperature different from the incubation condition, because re-equilibration can occur during loading and migration.

ARTGEL takes the opposite approach. Rather than trying to make the gel kinetically silent, the platform treats it as a well-defined and controllable reaction environment. Because confinement within the gel matrix may alter association rate constants, dissociation rate constants, and equilibrium dissociation constants, the instrument enables two complementary types of measurement. First, electrophoretic separation spatially resolves monomers, dimers, fragments, aggregates, and higher-order assemblies, directly testing whether an assumed association model is adequate. Second, by operating at the same temperature as matched bulk measurements, ARTGEL allows in-gel equilibrium and rate constants to be extracted and compared with their solution values, revealing how confinement modifies reversible self-assembly.

Meeting these goals demanded solving several engineering problems that conventional electrophoresis systems were never designed to address. Joule heating in salt-containing buffers, including the magnesium chloride buffers used for DNA origami work, raises the gel temperature, broadens bands, and perturbs both mobility and reaction kinetics. Attempts to regulate temperature by adjusting electrophoresis power inherently couple thermal control to electric-field strength, preventing independent control of these variables. Prolonged electrophoresis in high-salt environments also promotes electrode fouling through electrochemical precipitation, which increases electrode resistance and alters the effective voltage across the gel over time.

The ARTGEL architecture addresses each of these challenges with a distinct subsystem. Thermal regulation uses a two-stage approach: coarse control comes from a large external buffer reservoir, roughly 7.6 liters, heated by a 150-watt immersion heater and continuously circulated through the gel box by peristaltic pumps, while fine adjustment is provided by a 24-watt thermoelectric Peltier module coupled to an aluminum heat-spreading plate beneath the gel. The buffer reservoir provides thermal stability and spatial uniformity, while the thermoelectric module enables rapid and precise temperature tuning. Multiple 100-kilohm thermistors, housed in nickel-tipped probes for thermal contact and electrical insulation, monitor temperature in the gel, the aluminum plate, the buffer reservoir, and the ambient environment.

Electrical stability is maintained by an automated electrode-wiping mechanism, perhaps the platform’s most distinctive feature. In magnesium chloride buffer, electrochemical deposition of magnesium hydroxide on the cathode increases electrode resistance, lowering the current and consequently the voltage drop across the gel. ARTGEL mitigates this with a custom-built reciprocating linear actuator that drives a scrubbing sponge along the negative electrode at a stroke frequency of roughly one pass every five to ten seconds. Three-dimensional printed plugs fitted into the gel wells prevent scraped salt particles from entering the gel. The effect is dramatic: without wiping, electrophoresis current fell from approximately 140 milliamperes to 80 milliamperes over 24 hours, while with wiping the current remained stable at 139.5 plus or minus 2.5 milliamperes throughout the experiment.

Control electronics are built around two independently operating Arduino microcontrollers. Arduino 1 regulates gel temperature via the thermoelectric module under proportional-integral feedback, while Arduino 2 regulates buffer temperature in the reservoir. Each microcontroller interfaces with an H-bridge motor driver that switches voltage polarity, enabling the Peltier module to both heat and cool. Pulse-width modulation at 976 hertz, far faster than the thermal response timescale of the gel box, means gel temperature is set by the PWM duty cycle rather than instantaneous power. A MATLAB graphical user interface provides real-time visualization of temperature, voltage, and current, along with manual, proportional, and proportional-integral control modes, and automatically logs all experimental parameters into structured data files.

Validation experiments demonstrate the platform’s performance across multiple dimensions. In a 16-hour electrophoresis run at 50 volts with a 1.5 percent agarose gel regulated at 30 degrees Celsius, the gel temperature held steady at 30.00 plus or minus 0.03 degrees Celsius after the initial two-hour equilibration, while the buffer reservoir held 31.0 plus or minus 0.2 degrees Celsius. Spatial temperature uniformity was measured at three locations within the gel, revealing a range of approximately 0.6 degrees Celsius at the 30-degree setpoint and 1.1 degrees Celsius at 40 degrees, substantially larger than the temporal variation at the feedback-control location but still reasonably uniform for quantitative work.

The biological payoff comes from experiments with DNA origami, the technique introduced by Paul Rothemund in which a long scaffold strand is folded by shorter synthetic strands into prescribed nanoscale geometries. Saha and Fraden used DNA origami building blocks as a model system for reversible monomer-dimer association. When reactive samples pre-incubated at temperatures from 40 to 30 degrees Celsius were loaded into an unregulated gel at room temperature, all samples converged to nearly identical intensity profiles dominated by dimers, demonstrating that re-equilibration during the 10 to 20 minutes of sample entry had erased the initial thermodynamic differences. Under ARTGEL’s actively regulated temperatures from 26 to 32 degrees Celsius, the initial states were preserved, with dimer population increasing monotonically as temperature decreased.

In the culminating demonstration, control and reactive samples pre-equilibrated at 28 degrees Celsius were loaded into adjacent lanes of a gel maintained at that same temperature, with samples introduced sequentially at multiple time points during a single run lasting up to nearly 25 hours. Control monomers and dimers separated into well-resolved peaks, while reactive samples exhibited continuous intensity distributions between those peaks, with characteristic asymmetric skewing and shoulders arising from ongoing monomer-dimer interconversion during migration. Fitting all concentration profiles simultaneously to reaction-diffusion-advection equations allowed extraction of in-gel kinetic and equilibrium parameters, which can be compared directly with complementary bulk light-scattering measurements performed at the same temperature. Because the gel resolves the spatial distribution of species present, it can also reveal side products, aggregates, or intermediates that ensemble-averaged bulk methods would miss.

ARTGEL is released as a fully documented open-source platform under CERN-OHL-P hardware, MIT software, and CC BY 4.0 documentation licenses, with a total bill of materials cost of approximately 2,460 dollars, dominated by the commercial electrophoresis power supply and gel box. The authors acknowledge that spatial temperature variation exceeds temporal stability, that thermistor probes may locally perturb electric and temperature fields, and that direct measurement of the voltage drop across the gel would provide more rigorous characterization than the current and migration-velocity proxies used here. Future extensions could integrate real-time fluorescence imaging and direct electric-field mapping. Even so, the platform establishes gel electrophoresis as a quantitative tool for reactive transport, reversible self-assembly, and temperature-sensitive nanoscale systems in porous media, opening a path toward systematic study of how confinement alters the fundamental constants of biomolecular association.

Subject of Research: A temperature-regulated open-source gel electrophoresis platform for quantifying reversible biomolecular association in gels

Article Title: ARTGEL: A temperature-regulated gel electrophoresis platform for quantitative studies of reversible association

Article References: Saha, R., & Fraden, S. (2026). ARTGEL: A temperature-regulated gel electrophoresis platform for quantitative studies of reversible association. HardwareX, Article e00847. https://doi.org/10.1016/j.ohx.2026.e00847

Image Credits: AI Generated

DOI: 10.1016/j.ohx.2026.e00847

Keywords: gel electrophoresis, ARTGEL, DNA origami, temperature control, electrophoretic mobility shift assay, reversible association, open-source hardware, reaction-diffusion-advection, Peltier thermoelectric, electrode fouling, biomolecular kinetics, Brandeis University

The device, described in the open-access journal HardwareX by Gianmauro Fontana, Nicola Iacono, Gabriele Papadia and Simone Pio Negri, is designed to manipulate surface mount technology (SMT) components with planar dimensions from 0.5 by 0.5 millimetres up to 8 by 8 millimetres, with heights between 0.3 and 5 millimetres. That range spans the vast majority of parts routinely assembled onto PCBs, from tiny passive resistors to sizeable ball grid array packages. By integrating two complementary grasping technologies into one end-effector, the gripper eliminates the frequent tool changes that erode throughput in flexible manufacturing, and it adds a third, hybrid operating mode in which both grasping mechanisms act on the same component simultaneously.

Each of the two primary modes has well-known strengths and weaknesses. Vacuum grippers, which use suction cups connected to a Venturi-effect vacuum generator, excel at delicate handling of flat, smooth components and can be miniaturised cheaply, but they apply only a single vertical force and can struggle to release micro-scale parts, where electrostatic, van der Waals and capillary adhesion forces cause components to stick to the tool. Friction grippers, by contrast, use two opposing fingers to grip parts from the sides, providing firmer, bilateral holding, yet they occupy more space, risk crushing fragile parts without force control, and suffer their own sticking effects on very small components. Hybrid designs have been explored before, combining electrostatic, electrothermal or capillary techniques, but the new tool stands out by pairing the two methods most common in industrial PCB assembly and by packaging them in a modular, largely 3D-printed body.

Mechanically, the gripper is organised around three sub-assemblies. A fixed 3D-printed base supports a central vacuum tool holding an interchangeable micro suction cup, together with a mobile frame carrying two L-shaped fingers. This mobile frame is driven vertically by a single-acting pneumatic cylinder that develops a lifting force of about 22 newtons at 6 bar, deliberately sized to resist soldering forces of between 0.05 and 0.2 newtons acting along both vertical and horizontal axes. That robustness is not incidental: the fingers themselves are printed in a high-temperature resin from Formlabs that withstands soldering temperatures up to 240 degrees Celsius, allowing the tool to hold a component firmly in place while an operator, or another robot, solders it. This makes the gripper directly usable in collaborative robotics scenarios such as operator-assisted soldering, a capability few commercial alternatives offer.

Horizontal positioning of the fingers is handled by two low-cost miniature linear stages, each actuated by a two-phase stepper motor through a gear-and-lead-screw transmission. The stages provide a 9.1-millimetre stroke with a full linear step of 25 micrometres, and each can sustain the horizontal and vertical reaction forces of roughly 0.2 newtons that the fingers impose during grasping. The designers paid careful attention to tolerances in the pneumatic cylinder, specifying an H7/h6 mobile coupling that balances accurate positioning against low friction; a small deliberate leak even produces a mild air bearing between piston rod and cylinder. In the friction mode, with a closing force of 0.2 newtons per finger and an assumed polymer–metal friction coefficient of 0.5, the tool can hold components weighing up to about 0.2 newtons, while the suction cup adds a further, configurable contribution that scales with cup diameter, reaching nearly 0.6 newtons at 1 millimetre.

The control system is built around an Arduino Due microcontroller running an Atmel SAM3X8E ARM Cortex-M3 processor at 84 megahertz, paired with an Ethernet shield for TCP/IP communication with a supervisory PC. Two STSPIN220 stepper drivers command the finger stages, while MM10 linear potentiometers provide position feedback with an effective resolution of 2.68 micrometres through the microcontroller’s 12-bit analogue-to-digital converter. A second-order IIR low-pass filter with a 50-hertz cutoff suppresses sensor noise, cutting the standard deviation of position measurements by 87 percent to just 2 micrometres in the worst case. Solenoid valves and opto-isolated relays handle the two-state control of vacuum and the pneumatic cylinder, and an external EEPROM preserves configuration parameters through power failures. MATLAB scripts sit on top of this embedded layer purely as a supervisory and analysis tool, used for data logging, system identification and PID tuning rather than for real-time control.

The tuning workflow itself is a small masterclass in applied control engineering. The researchers first eliminated mechanical backlash with an open-loop warm-up movement, then measured the true linear step size using a Mitutoyo digital indicator with a 0.001-millimetre resolution. Stroke calibration and sensor sensitivity estimation were automated inside the firmware. Eight open-loop motion cycles per finger axis, with speeds from 3 to 24 millimetres per second and durations from 0.4 to 3 seconds sampled at 0.5 milliseconds, fed a first-order system identification in MATLAB; validation on held-back cycles achieved at least 96 percent fit accuracy. PI controllers, tuned for maximum robustness with anti-windup and speed feedforward compensation, then track trapezoidal motion profiles generated online by the firmware’s multi-threaded, pseudo-real-time scheduler, which separates actuation control, communication and manual-or-automatic mode management into independent loops.

Experimental validation put these numbers to the test. Thirty grasp-and-release cycles were run for each component and each grasping mode, using a ball grid array package measuring 8 by 6 by 0.8 millimetres and a 1005 resistor measuring just 1 by 0.5 millimetre. Friction and vacuum grasping achieved a perfect 100 percent pick-and-release reliability for both parts, and the hybrid mode matched that figure for the BGA component. Closed-loop tracking kept finger positioning errors within the 50-micrometre control tolerance, with the two fingers synchronised to within 30 milliseconds of each other. A stall-detection strategy, triggered when commanded displacement exceeds the estimated mechanical backlash, let the fingers stop independently upon contact with grasped parts or with neighbouring components on the board, protecting both the motors and the delicate electronics. Disturbance-rejection tests confirmed that the controllers recover their setpoints smoothly after unexpected external forces are applied and removed.

The tests also exposed an honest limitation. On the 1-millimetre resistor, the hybrid mode failed because of mechanical interference between the fingers and the suction cup, a problem the authors attribute to the current finger geometry rather than to the concept itself, noting that revised finger shapes could overcome it. They also map out the trade-offs clearly: friction grasping suits firm, accurate manipulation but needs more clearance, vacuum excels with delicate parts but holds them with only a single force, and the hybrid approach delivers the best holding stability and release precision, with the fingers’ upward motion acting as an integrated plug-like release mechanism against micro-scale adhesion, yet it is not yet ready for sub-millimetre components.

Even with those caveats, the economics are striking. The complete bill of materials comes to 562.66 euros, including upper-bound estimates for small hardware, printed parts and machined metal components, with an optional 750-euro automatic tool changer that can be replaced by a simple fixed interface. Most parts are additively manufactured, only a few require CNC machining, and every CAD file, schematic, firmware routine and MATLAB script is released under a Creative Commons Attribution 4.0 licence through a public repository. For research labs, small manufacturers and anyone building flexible robotic assembly cells, that combination of verified performance, multi-mode versatility and full open-source reproducibility makes the hybrid micro-gripper a genuinely compelling piece of hardware, and a signal of where low-cost, reconfigurable micromanipulation is heading.

Subject of Research: Design and experimental validation of a multi-mode hybrid vacuum-friction micro-gripper for robotic manipulation and assembly of surface mount technology components

Article Title: Multi-mode hybrid micro-gripper for micro-manipulation and micro-assembly

Article References: Fontana, G., Iacono, N., Papadia, G., & Negri, S. P. (2026). Multi-mode hybrid micro-gripper for micro-manipulation and micro-assembly. HardwareX, Article e00850. https://doi.org/10.1016/j.ohx.2026.e00850

Image Credits: AI Generated

DOI: 10.1016/j.ohx.2026.e00850

Keywords: micro-gripper, robotics, PCB assembly, surface mount technology, vacuum grasping, friction grasping, micro-manipulation, closed-loop control, open source hardware, additive manufacturing, Arduino Due, micro-assembly

The motivation comes from a very concrete problem. Volcano observatories, seismic networks, and geophysical stations in regions without cellular or wired infrastructure need radio links that can carry uninterrupted sensor data across ten to twenty kilometres. A triaxial seismometer sampling at 200 samples per second with 24 bits per axis generates a raw stream of 14.4 kilobits per second, but telemetry protocols and encapsulation overheads such as MiniSEED formatting standardise on a 115,200 bits per second serial interface at the sensor output. To prevent buffer accumulation, the wireless link must sustain goodput at or above that serial speed. LoRa, the proprietary chirp spread spectrum modulation that has become ubiquitous in smart agriculture and volcanic monitoring networks, simply cannot deliver: at the high spreading factors required for robust long-distance links, its effective air rate collapses to one to five kilobits per second, making continuous high-rate streaming fundamentally impossible.

The research team, affiliated with monitoring efforts around the active Misti and Sabancaya volcanoes in southern Peru, validated the throughput limitation empirically. In comparative benchmarks against commercial Ebyte E22 modules at 433 MHz and 915 MHz, both sub-gigahertz LoRa systems saturated at a maximum sustained goodput of just 29.38 kilobits per second, enforced by a physical packet inter-arrival floor of 65.35 milliseconds. That is a shortfall of nearly four times against the 115.2 kilobits per second target, meaning such links can carry a 100-samples-per-second seismic stream but cannot handle a 200-samples-per-second stream with any robust margin. Previous work on the 16-kilometre Misti–Arequipa path had already confirmed the geometric feasibility of the radio link while highlighting exactly this throughput wall.

OpenFLRC’s answer is to move to the 2.4 GHz industrial, scientific and medical band and exploit FLRC, or Fast Long-Range Communication, a modulation mode native to the SX1280 transceiver family. In its fastest configuration, FLRC achieves a 1.3 megabit per second air rate with a receiver sensitivity of minus 97 dBm, sufficient for multi-kilometre links. The team’s carrier board integrates an Ebyte E28-2G4M27SX radio front-end delivering up to 27 dBm, or 500 milliwatts, of output power through a Skyworks power amplifier, alongside an ESP32-S3 dual-core microcontroller running at 240 MHz with 16 MB of flash and 8 MB of PSRAM. Crucially, the design grants users bare-metal control over the radio, exposing internal hardware buffers, explicit transmit and receive timings, and direct SPI interrupts through a custom C++ library, a level of deterministic control that closed commercial LoRa modules abstract away entirely.

The engineering details reveal why the platform performs as it does. Driving a 500-milliwatt power amplifier continuously under high-rate streaming draws rapid current pulses peaking at 550 milliamperes with nanosecond-scale rise times, which would destabilise a typical breadboard or prototype supply. The carrier board embeds a five-capacitor decoupling ladder directly adjacent to the radio module’s power pins: two 150-microfarad low-ESR tantalum capacitors acting as a local bulk energy reservoir, in parallel with three high-frequency X7R ceramic capacitors. A continuous 1-ounce copper ground plane on the board’s underside, stitched to the module with thermal vias, acts as a passive heat spreader for the roughly 1.3 watts dissipated as heat during full-power transmission. The board also routes the radio’s transmit and receive enable lines through dedicated low-capacitance traces, allowing the firmware to switch the RF front-end deterministically within 2.5 microseconds and preventing destructive amplifier reflections during transmit-to-receive turnarounds.

The firmware architecture is equally deliberate. Under FreeRTOS, the dual-core processor divides labour asymmetrically: Core 0 ingests the incoming 115,200 bits per second serial stream into a lock-free circular ring buffer in RAM, while Core 1 runs a dedicated radio scheduler that fetches 117-byte chunks and pushes them to the SX1280’s FIFO over an 18 MHz SPI bus with direct memory access, shrinking each payload transfer to roughly 56 microseconds. Radio state transitions are governed strictly by a hardware interrupt that triggers a RAM-cached fast interrupt service routine, eliminating the scheduling jitter that plagues polling-based designs. The team’s timing budget analysis shows a minimum theoretical packet cycle of 840.9 microseconds, and the empirical benchmark achieved 884.3 kilobits per second of goodput at a one-millisecond packet interval, corresponding to a 73.1 percent channel efficiency relative to the raw 1.3 megabit per second air rate. Notably, 82 percent of Core 0’s processing capacity and more than 470 kilobytes of SRAM remain free for user data acquisition and edge signal processing.

Validation was conducted with unusual rigour for open hardware. Rather than relying on uncontrolled over-the-air tests, the team built a conducted radio-frequency bench using a calibrated chain of SMA attenuators totalling up to 145 decibels of path loss, characterised segment by segment with a NanoVNA vector network analyser at 433 MHz, 915 MHz, and 2.44 GHz. This approach isolates true receiver sensitivity and firmware behaviour from the multipath fading, interference, and antenna pointing errors that make field measurements irreproducible. In attenuation sweeps, the sub-gigahertz LoRa links sustained near-unity packet delivery up to 130 decibels of conducted path loss, while the 2.4 GHz FLRC link held a 96.2 percent delivery ratio at 125.8 decibels before failing completely, a roughly five-decibel penalty consistent with the higher noise bandwidth of FLRC compared to narrow-band chirp spread spectrum.

Spectral measurements with a TinySA Ultra analyser confirmed the platform’s regulatory compliance. The occupied bandwidth measured between 1.336 and 1.347 megahertz across three operating channels, closely matching the configured FLRC parameters, and second-harmonic suppression ranged from 38.5 to 41.8 decibels below the carrier, comfortably within FCC Part 15.247 and ETSI EN 300 328 emission limits. The power control loop proved highly linear across an 18-decibel dynamic range. Link-budget emulation for the 16.4-kilometre Misti–Arequipa volcanic corridor, based on the ITU-R free-space model and the empirical sensitivity thresholds, indicates the link can theoretically close at that distance, though the authors recommend upgrading to 19 dBi parabolic grid antennas or adding an intermediate repeater to maintain a proper fade margin for field reliability.

The trade-offs are candidly acknowledged. The 2.4 GHz band incurs a 7.9-decibel free-space path loss penalty compared to 915 MHz, making the system dependent on line-of-sight conditions, and continuous full-power transmission demands careful thermal management in any field enclosure. The v1.0 firmware implements dedicated point-to-point streaming only, with multi-node contention protocols and the SX1280’s built-in time-of-flight ranging engine reserved for future releases. Yet the regulatory picture favours the chosen band: sub-gigahertz spectrum is fragmented regionally and subject to duty-cycle limits as low as 0.1 percent in Europe that legally prohibit continuous telemetry, whereas the 2.4 GHz band is globally harmonised with no duty-cycle restrictions, and rain attenuation over a 16-kilometre path is negligible at these frequencies.

Perhaps most striking is the price and accessibility. Each complete transceiver node costs 32.70 US dollars, built from commodity modules and a two-layer printed circuit board, and the entire project, including schematics, gerber files, firmware, bill of materials, calibration data, and benchmark videos, is published under a Creative Commons Attribution 4.0 license and certified by the Open Source Hardware Association under UID PE000005. For research groups monitoring volcanoes, earthquakes, or any high-rate phenomenon in infrastructure-poor regions, OpenFLRC demonstrates that the era of choosing between long range and sufficient bandwidth may finally be ending, and that a thirty-dollar open board can do what expensive proprietary telemetry systems have long monopolised.

Subject of Research: Open-source 2.4 GHz FLRC wireless transceiver hardware for high-throughput, low-latency continuous scientific telemetry

Article Title: Open-source SX1280 2.4 GHz FLRC transceiver: Overcoming sub-GHz LoRa bottlenecks for high-rate, low-latency continuous telemetry

Article References: Choquepuma, K. J. C., Rodriguez, K. E. A., Arenas Mamani, F. A., & Hilario-Tacuri, A. (2026). Open-source SX1280 2.4 GHz FLRC transceiver: Overcoming sub-GHz LoRa bottlenecks for high-rate, low-latency continuous telemetry. HardwareX, Article e00848. https://doi.org/10.1016/j.ohx.2026.e00848

Image Credits: AI Generated

DOI: 10.1016/j.ohx.2026.e00848

Keywords: OpenFLRC, SX1280, FLRC modulation, LoRa bottleneck, wireless telemetry, volcano monitoring, seismic networks, ESP32-S3, open-source hardware, 2.4 GHz ISM band, packet delivery ratio, HardwareX

Yet despite its ubiquity, the technology of core opening has remained oddly invisible. Researchers at the EDYTEM laboratory, a joint unit of CNRS and Université Savoie Mont-Blanc in Chambéry, France, found that only two scientific publications describing a core opening device have appeared since 1969. Most laboratories either buy commercial models adapted from craft machinery or bolt together homemade devices whose designs live in workshops rather than journals. The result is a strange gap in the scientific record: a procedure used across thousands of studies is almost never described, validated, or shared, even though the cutting method directly affects the quality of the sediment surface and every sample taken from it.

Now, Raphaël Gallet and Fabien Arnaud of EDYTEM have published a complete, buildable answer in the journal Scientific Drilling: the EDYTEM Manual Core Opening Bench, or MCOB, a hand-operated device that slices sediment cores open with a static blade mounted on a sliding sled. The design targets the most common core formats, cutting polyvinyl chloride liners up to 1.5 meters long with walls up to 3 millimeters thick and external diameters of 63 and 90 millimeters, and every drawing, parts list, and assembly guide is available online at no charge under a Creative Commons license, meaning any laboratory with basic workshop access can reproduce the entire machine.

The engineering logic behind the MCOB starts with the failure modes it is designed to eliminate. Historically, cores were often opened with circular rotating blades, a technique that is fast and efficient but produces a shower of plastic shards and micro-debris that can contaminate the very sediment researchers are trying to study. Vibrating blades mitigate that problem but introduce their own issues. A static blade, the authors argue, mounted on a sled that glides along a rigid frame, offers the best of both worlds: a regular, symmetric longitudinal cut without the plastic contamination. Their design builds on an earlier static blade approach described in the literature in 2011, refined through months of trial and error into a fully documented open-source machine.

Structurally, the bench breaks down into six subsystems, each documented with computer-aided design files created in FreeCAD. The frame is built from 40 by 40 millimeter aluminium slot profiles with 8 millimeter channels, joined with screwed T-nuts and reinforced with aluminium brackets for rigidity. The guiding system uses a commercial SBR20 linear rail shaft two meters long, carrying four square ball-bearing blocks that keep the cutting tool on a perfectly straight 180-centimeter path. On this rail rides the tool carrier sled, an assembly of eighteen machined parts bolted together, which hosts the interchangeable cutting tools. Everything is deliberately mechanical: no motors, no electronics, just steel, aluminium, and hand power.

That hand power is delivered through the driving system, which the authors identify as the component under the greatest mechanical stress. Turning the crank handle requires a torque of 6.5 newton meters, so the team chose a gear-reduced double-chain transmission using standard 06B1 roller chains running on sprockets mounted to 20 millimeter shafts. A 21-tooth sprocket on the crank drives a 76-tooth sprocket, a gear ratio that multiplies the operator’s input force by roughly 3.6, making the long cutting stroke smooth and controllable with human muscle alone. The sprockets, crank, and shafts are pinned together and all components were sourced from ordinary commercial suppliers, keeping the build within reach of any reasonably equipped laboratory.

Holding the core steady during the cut is its own engineering puzzle, solved by a two-part clamping system. Below, an HDPE half-tube, cut 8 millimeters below its half-diameter and fitted with adjustable wedges, cradles cores of varying diameters on five 3D-printed supports. Above, a matching half-tube assembly presses down on the core to prevent deformation, sliding, or rotation as the blades bite through the liner. Two cylinders at either end, 3D-printed in PLA, maintain the precise gap between the upper and lower half-tubes and block the core from sliding under cutting forces, each machined with wide, deep grooves so the blades can pass unobstructed at the start and end of their stroke. Static stops, centring pins, and two clamping devices complete the fixture.

The cutting head itself reflects the most refined iteration of the design. Two tool carrier assemblies, one on each side of the core, cut both sides of the liner simultaneously. On each side, the first tool to engage is a Sandvik CoroTurn 107 carbide insert of the type used for machining plastic and aluminium, mounted on a custom aluminium holder. It scores a shallow, 0.5-millimeter-deep V-shaped incision into the liner wall. Immediately behind it, a commercial cutting blade follows that groove and completes the cut through the PVC. The V-groove acts as a guide rail for the blade, ensuring a straight, clean, symmetric cut. Two distinct tool sets allow quick switching between 63 and 90 millimeter liners, and a dedicated adjustment tool fine-tunes blade positioning for each setup, with shim adjustments accommodating other diameters.

The payoff, the authors report, has been more than a year of continuous use at EDYTEM by both laboratory staff and external users, during which the bench proved efficient and robust, needing only minor sled alignment adjustments and routine replacement of blades and inserts depending on core diameter. The supplies cost around 3000 euros, a figure the team notes needs re-evaluation after recent inflation and which excludes development and assembly time, but that remains a modest investment for a machine that can anchor an entire core processing workflow. Because the device is hand operated, it also avoids the stricter safety regime that electric motors would demand, and it can be transported to the field when necessary. The team explicitly invites researchers and engineers to adopt, adapt, and improve the design, and to share their enhancements with the community. For a device that quietly underpins thousands of studies a year, bringing core opening out of the workshop closet and into the open-source era may prove one of the more consequential acts of scientific sharing this year.

Subject of Research: Design of a reproducible hand-operated static blade bench for opening sediment core liners

Article Title: Hand-operated fully reproducible static blade core opening bench

Article References: Gallet, R., & Arnaud, F. (2025). Hand-operated fully reproducible static blade core opening bench. Scientific Drilling, 34(1/2), 21-27. https://doi.org/10.5194/sd-34-21-2025

Image Credits: AI Generated

DOI: 10.5194/sd-34-21-2025

Keywords: sediment cores, core opening, open-source hardware, Scientific Drilling, PVC liners, static blade, paleoclimate, laboratory equipment, EDYTEM, 3D printing, limnology, technical development

The platform, described in the journal HardwareX by Marcel Bentancor, Esteban Casaretto, Omar Borsani, Gastón Quero and Mercedes Muñoz of Universidad de la República, is a two-axis Cartesian gantry that glides a camera head over a grid of up to 24 potted plants inside a standard growth chamber. It adopts a sensor-to-plant architecture, meaning the plants stay put while the imaging unit travels to them, avoiding the conveyors, robotic arms and pot-handling machinery that make commercial systems such as PSI’s PlantScreen or Phenospex’s PlantEye F500 so expensive. Those commercial platforms can exceed 100,000 dollars and, in some configurations, approach a million; the Uruguayan team’s design captures the essential multimodal imaging capability at roughly one percent of that cost.

Technically, the machine is built around a welded frame of square steel tubing, aluminum guide rails and sliding-door rollers, with motion provided by two NEMA 23 stepper motors driving 3D-printed rack-and-pinion transmissions. Rather than relying on belt encoders, lead screws or cumulative step counting, the system uses inexpensive Hall effect sensors paired with small permanent magnets as discrete positional references. When a carriage passes over a magnet, the sensor registers the stop, so the platform tolerates occasional lost steps or slippage without needing recalibration. This is a deliberate engineering choice for robustness: the head stops at 24 predefined positions arranged in a 6-by-4 grid, and each stop is verified magnetically rather than inferred from motor counts that can drift over time.

The imaging payload pairs a Raspberry Pi HQ Camera fitted with an Arducam lens for visible-spectrum photography with a FLIR Lepton 3.5 thermal sensor mounted on a PureThermal Mini Pro board. A single Raspberry Pi 3B+ orchestrates everything, from motor control and Hall sensor reading to synchronized dual-image capture, and connects to the laboratory network over WiFi for remote monitoring. At every grid position the system saves an RGB photograph alongside six thermal outputs, including raw 16-bit radiometric frames, NumPy arrays, TIFF images and a per-pixel temperature matrix in degrees Celsius. Users schedule acquisition sessions through a Tkinter graphical interface, and an emergency stop button halts all motion instantly. The entire design, from STL files to Python scripts, is released under a Creative Commons Attribution-ShareAlike 4.0 license.

The software ecosystem is split into two modules. The onboard module handles real-time acquisition autonomously, traversing the plant grid in an S-shaped pattern and homing the carriages back to rest after each session. The offline module, running on any standard computer, performs the heavy analytical lifting: lens distortion correction using OpenCV chessboard calibration, deep-learning segmentation of plant tissue, mask post-processing, homography-based registration between the RGB and thermal images, and statistical extraction of canopy temperature. A U-Net convolutional network with a ResNet34 encoder, trained on just 100 manually annotated images, achieved an Intersection over Union of 0.95 and a Dice coefficient of 0.975 on validation data, confirming that the platform’s images are sharp enough for state-of-the-art automated analysis.

The homography pipeline deserves particular attention because it solves a genuinely tricky multimodal problem. The RGB camera produces images at 640 by 480 pixels, while the Lepton thermal sensor resolves only 160 by 120 pixels with a different viewing geometry. By defining corresponding reference points on both image types, the calibration tool computes a projective transformation that maps RGB-derived plant masks onto the thermal frame, giving each temperature pixel a biological identity. Because the resolution mismatch means the projected masks are approximate, the researchers built an interactive editor that lets users refine thermal mask boundaries by hand, with temperature histograms displayed in real time. The result is canopy temperature statistics computed predominantly from actual plant tissue rather than background pot or soil pixels.

To validate the system, the team ran a seven-day water deficit experiment with 24 soybean plants, half regularly irrigated and half subjected to drought by withholding water. Over 22 scheduled acquisition sessions, the platform captured 528 paired RGB and thermal images, of which 526 thermal frames were retained after two sensor initialization failures. The projected leaf area curves from the RGB pipeline cleanly separated the two treatments, with drought-stressed plants showing a marked decline from day five onward. The thermal data told the complementary physiological story: as stomata closed to conserve water, evaporative cooling was lost and canopy temperature rose measurably above that of the irrigated controls, exactly the signal that infrared thermography has been used to detect since the early 2000s.

Two incidental findings showcase the platform’s sensitivity. The time series captured nyctinasty, the daily rhythmic folding of soybean leaflets driven by cellular turgor, as an oscillation in projected leaf area synchronized with the light cycle, and revealed that this movement was attenuated in the water-stressed plants, consistent with the known link between turgor and leaf posture. More strikingly, when an unexpected power outage interrupted the growth chamber’s lighting on day four, the platform registered the anomaly as a dip in leaf area, demonstrating that the system can double as a sentinel for environmental disturbances that would otherwise go unnoticed between manual measurements.

The researchers are careful to position the platform not as a rival to high-throughput commercial facilities but as a complement occupying a specific experimental niche: routine, high-frequency screening of small to medium plants in growth chambers, particularly for early-stage evaluation of genetically modified lines before committing resources to greenhouse or field trials. Compared with previously published open-source systems, it is, according to the authors, the only one combining two-axis automated positioning, integrated RGB and thermal imaging, and cross-modal registration software for under 1,200 dollars. Limitations remain, including the low resolution of the Lepton sensor and the need for occasional manual mask curation, but these are framed as conscious trade-offs in favor of affordability and ease of replication.

The broader significance may lie in who can now participate in plant phenomics. Because the bill of materials draws on hardware-store steel, off-the-shelf electronics and 3D-printed parts, laboratories in countries with limited technological infrastructure can build, repair and modify the platform without depending on specialized suppliers. The modular design invites sensor swaps, trajectory changes and future additions such as automated irrigation, gravimetric water monitoring or three-dimensional reconstruction. At a moment when artificial intelligence and predictive models are hungry for large volumes of high-quality phenotypic data, a thousand-dollar robot that can watch a chamber full of plants grow, wilt and sweat around the clock is a quietly radical piece of scientific infrastructure, and its full blueprints are free for anyone to download and build.

Subject of Research: An open-source, low-cost robotic platform for automated RGB and thermal imaging of plants in controlled environments

Article Title: Open-source hardware platform for automated, non-invasive plant phenotyping through combined RGB and thermal imaging

Article References: Bentancor, M., Casaretto, E., Borsani, O., Quero, G., & Muñoz, M. (2026). Open-source hardware platform for automated, non-invasive plant phenotyping through combined RGB and thermal imaging. HardwareX, Article e00846. https://doi.org/10.1016/j.ohx.2026.e00846

Image Credits: AI Generated

DOI: 10.1016/j.ohx.2026.e00846

Keywords: plant phenotyping, open-source hardware, thermal imaging, RGB imaging, Raspberry Pi, growth chamber, drought stress, deep learning segmentation, U-Net, soybean, HardwareX, canopy temperature

The platform, called the OpenWater Hub, was developed by Hany A. Elesawy, Ahmed I. Ahmed, Yahia A. AboZaid, and colleagues at institutions affiliated with the Academy of Scientific Research and Technology in Egypt, and described in the journal HardwareX. Its central innovation is architectural rather than exotic: instead of relying on one processor to juggle sensor polling and motor control, the board carries two ATmega128A microcontrollers that operate in complete isolation from one another. One chip, designated MCU1, devotes itself entirely to real-time actuation, generating the pulse-width modulation signals that drive motors and actuators. The other, MCU2, runs a non-interruptible bare-metal loop that handles Modbus RTU polling over an RS485 serial bus, parses raw byte streams from industrial probes, and validates every message with local CRC16 checksums. Because no data-carrying copper traces connect the two chips, electrical noise from motor regulators cannot corrupt serial communications.

That separation matters because half-duplex RS485 networks demand strict timing determinism. The master node must toggle transceiver pins with microsecond precision, and on a single-core logger, a Modbus request blocks the processor, disrupting real-time PWM signals and causing robotic control loops to stutter. The authors point out that single-board computers running Linux introduce packet-colliding timing jitter from context switching, while platforms that tunnel RS485 traffic through packetized networks lose the guaranteed silent intervals that legacy sensors require. By giving each task its own dedicated silicon, the OpenWater Hub sidesteps these failure modes entirely, and the team demonstrated that a soft robotic fish could be driven continuously while RS485 telemetry flowed without a single lost frame.

The board is also unusually generous with power for its price. A fuse-protected 24-volt bus supplies up to 24 watts to sensors, enough to handle the high inrush currents drawn by the mechanical wiper motors inside optical sondes. Four independent LM2576 step-down regulators feed the actuation channels, each delivering up to 3 amps of adjustable voltage, defaulting to 8.85 volts but tunable between roughly 5 and 12 volts by swapping a single resistor. Those PWM outputs can drive brushless electronic speed controllers directly or switch external MOSFETs to power heavy DC water pumps and dosing valves. Input protection comes in two stages: a 24-volt transient voltage suppressor clamps surges, while a 20-volt Zener diode acts as an under-voltage lockout that prevents the logic from booting during brownout conditions.

Perhaps the most radical feature is what the design refuses to do: restrict users. Any sensor that speaks RS485 differential signaling, formats its data as Modbus RTU, and accepts 12 to 24 volts can be attached without vendor approval, from high-end fluorometers to budget-tier pH and temperature probes. Wireless telemetry is equally modular, with two UART sockets that accept LoRa, Wi-Fi, Bluetooth, or cellular radio modules, one per microcontroller, allowing sensor data and robot telemetry to travel on separate frequencies. Researchers retain complete, unencrypted ownership of their high-resolution data, a stark contrast to commercial ecosystems in which users must manually export log files in one-hour segments because the closed software will not do otherwise.

From one board, the team derived four deployment configurations. Case Zero is the fully populated PCB on a bench, serving as an open sandbox for sensor calibration and robotic testing. Case C transforms the hardware into a portable Lab-in-a-Box, housed in an aluminum tool case with a seven-inch touch screen, sixteen splashproof aviation connectors wired to the RS485 bus, and a hybrid power system that switches between mains electricity and a solar-charged 12-volt lead-acid battery boosted to 24 volts. Case A mounts a single board inside an IP66 enclosure atop a floating platform built from nine modular HDPE pontoon cubes and an aluminum truss, powered entirely by a 50-watt solar panel and an MPPT charge controller. Case B stacks a second board into the same enclosure, converting the station into a robotic support hub that relays commands down a 50-meter tether and injects power to tethered underwater vehicles.

The validation data are striking for hardware this inexpensive. The fully assembled core PCB costs $45.60, the portable lab $292.60, and the complete floating station $475.60, figures that undercut commercial relay modules alone, which can push a closed system toward $1,600. During a ten-day continuous benchmark, the hub polled its sensors every 34.1 seconds and transmitted 25,314 telemetry packets, of which 25,308 reached the cloud database, a delivery ratio above 99.97 percent with no hardware timeouts. The high-resolution record even captured transient chemical shifts that the commercial reference meter, limited to one-hour logging intervals, completely missed.

The power analysis reveals both the promise and the constraints of the platform. A LoRa configuration with three sensors attached draws enough energy to exhaust a 108-watt-hour battery in roughly four days without intervention, because the probes themselves impose a combined 577.9-milliwatt load even while the system sleeps. The solution is physical rather than software-based: an optional high-side P-channel MOSFET module, triggered by a single microcontroller pin, cuts power to the sensor array entirely during sleep phases, saving about 13.7 watt-hours per day and extending endurance toward the theoretical maximum of nearly nine days. The authors caution that low-side switching would sever the ground reference and route return currents through the RS485 data lines, destroying the transceiver, a warning they emphasize as a strict physical necessity.

The team is candid about the design’s limits. The shared ground plane precludes galvanic isolation, so seawater intrusion through connectors could create ground loops that skew electrochemical measurements. The 8-bit processors lack hardware floating-point units, ruling out onboard wave spectrum calculations, and the 3-amp-per-channel regulator ceiling means heavy winches or sampling pumps would need external converters. The physical separation of the two microcontrollers also forces builders to choose between a wireless LoRa bridge and a jumper wire, demanding some electronics literacy. Future work will move from controlled test tanks to open-sea deployments, where wave impact, salt corrosion, and biofouling will test the platform’s durability over months rather than days.

Even so, the significance of the release is hard to overstate. Coral reefs shelter at least a quarter of all marine species and anchor a substantial share of the ocean’s roughly 2.5 percent contribution to global GDP, yet monitoring them affordably and densely has remained an unsolved engineering problem. By fusing industrial-grade sensing, deterministic robotics control, and open licensing into a single sub-fifty-dollar board, the OpenWater Hub offers research groups, coastal communities, and citizen scientists a way to build monitoring infrastructure that they own outright, modify freely, and scale from a handheld field kit to an autonomous offshore station without ever asking a vendor for permission.

Subject of Research: An open-source hardware platform for marine robotics support and water quality data acquisition

Article Title: OpenWater Hub: An open-source hardware platform for marine robotics support and water quality data acquisition

Article References: Elesawy, H. A., Ahmed, A. I., AboZaid, Y. A., Said, L. A., Samy, I., & Radwan, A. G. (2026). OpenWater Hub: An open-source hardware platform for marine robotics support and water quality data acquisition. HardwareX, 28, Article e00845. https://doi.org/10.1016/j.ohx.2026.e00845

Image Credits: AI Generated

DOI: 10.1016/j.ohx.2026.e00845

Keywords: open-source hardware, marine robotics, water quality monitoring, RS485, Modbus RTU, ocean observation, coral reefs, microcontrollers, LoRa telemetry, environmental sensing, floating sensor station, HardwareX

The choice of a hexacopter rather than the more common quadcopter is not cosmetic. With six brushless motors driving six propellers in a Hexa-X layout, the aircraft retains controlled flight even if one rotor fails, a margin of safety that matters enormously when the vehicle is dispatched over rubble, smoke or unstable terrain where a crash means losing both the airframe and the mapping data it carries. The redundant rotor configuration also increases total payload capacity, which is what allows the platform to carry multiple sensing systems at once. In disaster scenarios the aircraft can be deployed quickly without runways or significant ground infrastructure, and its maneuverability lets it thread through confined spaces and reach isolated zones that ground vehicles cannot access. The authors also emphasize the operating economics: small multirotors cost a fraction of larger aerial platforms, making repeated reconnaissance sorties financially realistic for agencies that must monitor an affected area many times over.

The thermal imaging payload centers on the FLIR Lepton 3.5, a remarkably small radiometric thermal camera that measures the actual temperature of every pixel rather than merely rendering a heat picture. The sensor is mounted on a tCam-Mini rev4 breakout board built around an ESP32-WROVER microcontroller with an onboard antenna, an open-source hardware and software design that streams the radiometric data over WiFi to a ground computer. Before flight, the camera’s housing is produced by 3D printing, with four STL components and two copies of a vertical holder printed to form an enclosure that shields the delicate sensor from vibration and mechanical stress during operation. Firmware is flashed to the ESP32 board using Espressif’s serial download tool, loading a bootloader, a partition table and the main tCam firmware in sequence; a dual-color LED confirms a successful boot by briefly turning red and then blinking yellow as the camera begins advertising its own WiFi access point. The companion desktop application then connects to the camera’s default address and displays the live thermal feed, allowing operators to detect human body heat and other thermal anomalies in real time even through smoke, darkness or visual clutter that would defeat an ordinary camera.

The mapping side of the system uses the Garmin LiDAR-Lite V3, a compact and lightweight laser rangefinder chosen for its accurate distance measurements and wide field of view. Because a single fixed sensor sees only one direction at a time, the team mounted it on a pan-and-tilt assembly built from two HS-422 servo motors and an aluminium bracket kit, letting the laser sweep across the terrain below. An Arduino Uno orchestrates the scanning: it toggles the sensor’s enable pin, manages the I2C clock and data lines used for communication, and arbitrates the mode-control pin through parallel resistors to prevent bus contention, all while driving the two servos through PWM signals. As the sensor sweeps, distance readings are transmitted over serial to a ground station, where an open-source interface written in C++ with the OpenGL graphics library converts each measurement into Cartesian coordinates and renders it as a cube whose color encodes angle and distance. The operator can fly through the emerging 3D point cloud while scanning is still in progress, and completed scans can be saved to file and reloaded for later analysis, producing the kind of terrain model that helps responders understand where paths, debris fields and structures lie.

The airframe itself follows a build path that any reasonably well-equipped workshop could follow. Six A2212 brushless motors rated at 1000 KV are bolted to the arms of an F550 hexacopter frame, with their bullet connectors routed through the arms before the electronic speed controllers are positioned. A power distribution board mounted on the lower frame plate feeds all six speed controllers, and every solder joint is tinned with flux to prevent the cold joints that can fail mid-flight. The top plate then encloses the electronics, with the battery carefully balanced along the centerline. An APM 2.8 flight controller with a built-in compass coordinates the six rotors, receiving commands from a Flysky FS-i6X 2.4 GHz transmitter and its ten-channel receiver. The team configured and calibrated the entire flight system using Mission Planner, an open-source ground-control application: firmware for the Hexa X frame is installed over a serial connection, the accelerometer and compass are calibrated by rotating the vehicle until calibration markers clear, the radio sticks are swept to their extremes to record their ranges, and the electronic speed controllers are programmed through a sequence of throttle-position beeps. Anti-vibration dampers sit between the frame and the controller to keep sensor readings clean.

Field validation put the whole assembly through its paces. The team performed pilot testing and initial flight calibrations before moving to full flight and field testing of the integrated platform, confirming aerial monitoring, environmental sensing and real-time wireless transmission of the thermal feed. Wireless transmission tests measured system performance characteristics such as the maximum achievable frame rate for the life-form detection stream, data that defines how quickly an operator on the ground can see a heat signature appear. The platform’s architecture also leaves room for growth: the authors note that the airframe can support a gripper mechanism for object retrieval, temperature and humidity sensors for environmental monitoring, and integration with Geographic Information System databases to sharpen situational awareness during response operations. Multi-sensor fusion of the LiDAR, thermal and environmental streams is presented as the path toward a comprehensive picture of a disaster zone, and the communication module could in principle relay temporary network connectivity into areas where infrastructure has been knocked out.

The build is also refreshingly honest about its limits, several of which will be familiar to anyone who has tried to put serious sensors on a small drone. The single biggest disappointment came during flight testing of the LiDAR: the team was unable to operate the scanner airborne because of the platform’s significant payload capacity and power limitations, a constraint the authors note is common to compact UAV-based LiDAR systems. Continuous LiDAR operation demands sustained laser emission and real-time computation, while the thermal camera needs uninterrupted power for image acquisition, so balancing sensor operation against flight stability and mission duration remains a central engineering challenge. The Garmin sensor itself is also slow: a complete scan yields roughly 92,000 data points, a process that can stretch over several hours when performed thoroughly. On the ground, that is acceptable; in the air, it would be impractical without a faster scanning approach or a lighter, more efficient sensor.

Other constraints are more exotic but no less instructive. The LiDAR’s laser ranging degrades on highly reflective surfaces and transparent materials such as glass, which scatter or pass through the beam rather than returning a clean reflection. Reliable serial communication required fixed-length data strings, so the software pads angular measurements and sensor values with leading zeros, an unglamorous detail that nonetheless determines whether the ground station parses the stream correctly. Perhaps most surprisingly for a civilian disaster tool, the FLIR Lepton 3.5 and certain LiDAR technologies fall under the International Traffic in Arms Regulations, the United States export-control regime for sensitive technologies. Complying with ITAR imposed administrative burdens that affected the project’s timelines, supplier selection and collaboration opportunities, and even sharing LiDAR-derived data with foreign entities required careful legal review. For a low-budget undergraduate project, these regulatory hurdles were as real an obstacle as any engineering problem.

What makes the publication notable is less any single component than the demonstrated end-to-end feasibility of the whole stack. A six-rotor aircraft with rotor-failure redundancy, a radiometric thermal camera that can spot living organisms through conditions that blind optical cameras, a LiDAR system that builds navigable 3D terrain models, and wireless streaming of the thermal data to an operator on the ground were all assembled for a total bill of materials of Rs. 73,689.35, with the single most expensive item, the LiDAR-Lite V3 at Rs. 23,215, costing less than many commercial camera drones on its own. All design files, from the LiDAR schematic and Arduino code to the STL enclosure prints and the tCam-Mini firmware, are archived in Zenodo repositories under Creative Commons and GNU General Public licenses. The authors frame the modular platform as a foundation for continued research in drone-assisted disaster management, with future work pointing toward machine-learning techniques for autonomous navigation that would reduce response times and keep human rescuers out of hazardous zones. For research groups and volunteer response teams in resource-constrained settings, it is a blueprint that turns a disaster-response capability once reserved for well-funded agencies into something a small team can build, fly and improve.

Subject of Research: Low-cost hexacopter platform integrating thermal imaging and LiDAR mapping for disaster management

Article Title: Thermal imaging and LiDAR mapping for disaster management with hexacopter

Article References: Vuucha, H., Jomon, J., Somasundaram, D., & M., M. S. (2026). Thermal imaging and LiDAR mapping for disaster management with hexacopter. HardwareX, Article e00841. https://doi.org/10.1016/j.ohx.2026.e00841

Image Credits: AI Generated

DOI: 10.1016/j.ohx.2026.e00841

Keywords: hexacopter, thermal imaging, LiDAR, disaster management, FLIR Lepton 3.5, Garmin LiDAR-Lite V3, open-source hardware, UAV, search and rescue, ESP32, 3D point cloud, Mission Planner

The technical logic behind Pearce’s objection is straightforward. In experimental science, hardware cost is a quantifiable variable, just like measurement precision, throughput, or error rate. When a paper describes an open-source instrument, the bill of materials is the specification that makes replication possible. Removing it does not merely soften a claim; it breaks the chain of reproducibility that peer review is supposed to guarantee. A peer-reviewed comparison of cost, reproducibility, and performance, Pearce writes, is no more an endorsement of one product than a methods-comparison paper is an endorsement of one technique. It is part of the scientific record needed for replication, evaluation, and efficient public spending. Demanding its removal forces researchers to publish incomplete research, which he characterizes as fundamentally anti-science and inconsistent with the United States government’s own public-access and open-science policies, which now emphasize free, immediate access to federally funded research outputs and the data underlying them.

The economics at stake are substantial. Peer-reviewed research has repeatedly demonstrated that open-source scientific hardware simply costs less than proprietary equivalents. A recent HardwareX review found average savings of 87 percent overall, rising to 92 percent for 3D-printed tools and 94 percent for tools that combine 3D printing with Arduino-class open-source electronics, while earlier case studies often reported savings in the 90 to 99 percent range. The United States currently spends billions of dollars annually on scientific equipment, much of it proprietary and often manufactured internationally. Pearce points to Finland as a cautionary benchmark: an analysis there found that Finnish science funders could save between 2.84 and 27.7 million euros per year simply by shifting to open-source purchasing. Scaled to the American research enterprise, he argues, a conservative estimate suggests federally funded science could run ten times faster, with ten times more equipment at the same cost, if open hardware became the default.

The letter offers a concrete illustration of what such savings look like in practice. An open-source syringe pump library, developed in the United States, documented a device that can be built for roughly 50 dollars in any American laboratory, while internationally manufactured proprietary equivalents cost 1,500 dollars and in some cases up to 2,500 dollars. Stating that price difference, Pearce insists, is not disparagement of the private sector; it is an empirical fact. That design library was downloaded thousands of times within its first months of publication, producing a calculated substitution valuation of between roughly 1 and 12 million dollars in savings to the scientific community in a single year. Since then, the designs have been downloaded tens of thousands of times, conservatively saving scientists tens of millions of dollars. Censoring such data, Pearce argues, prioritizes the commercial comfort of legacy vendors over the efficiency of government researchers and the success of American small businesses.

A central misunderstanding, according to the letter, is the assumption that open hardware is anti-commercial. By definition, open-source hardware licenses permit anyone, including private enterprises, to study, modify, distribute, make, and sell products based on a published design. Far from competing with industry, federal researchers who publish open designs are providing free, rigorously tested research and development to American small and medium-sized enterprises, enabling those firms to commercialize new products without the crippling overhead of initial prototyping and design. The Open Source Hardware Association, a United States-based organization composed primarily of such enterprises, exists precisely because open licensing can be a viable and profitable business model. Some authors in this field have gone so far as to call for all government-funded hardware research to be open source by default, on the grounds that the public has already paid for it.

The commercial track record cited in the letter is extensive. Arduino, whose open-source microcontroller platform has become the de facto standard for embedded prototyping in laboratories worldwide and underpins countless HardwareX publications, is now owned by Qualcomm, a San Diego-based technology firm with roughly 44 billion dollars in annual revenue. SparkFun Electronics of Boulder, Colorado, grew into a 32-million-dollar-a-year business with 146 employees by selling open-source electronic components and educational kits. Adafruit Industries in New York City generates more than 45 million dollars annually selling open-source hardware. Backyard Brains of Ann Arbor, Michigan, commercialized open-source neuroscience tools first described in peer-reviewed open hardware literature, while Opentrons of Long Island City democratized laboratory automation with open liquid-handling robots that displaced proprietary systems costing an order of magnitude more.

The examples extend into heavy manufacturing and even the military. LulzBot, headquartered and manufactured in Fargo, North Dakota, is an entirely open-source 3D printer manufacturer that has competed directly with proprietary incumbents and is used by the United States Marines, whose motto of improvising, adapting, and overcoming is well served by hardware whose designs can be freely modified and repaired. Adjacent firms have flourished on the same ecosystem: re:3D of Austin, Texas, a spinoff founded by NASA engineers, and MatterHackers of Lake Forest, California, both built thriving businesses around the open-source RepRap 3D printing project, the self-replicating rapid prototyper that catalyzed the modern desktop printing movement. Collectively, Pearce writes, these open hardware firms employ thousands of Americans and generate hundreds of millions of dollars in annual revenue, all built on openly licensed designs. When a federal researcher publishes a low-cost environmental sensor or diagnostic tool, he argues, they are planting the seeds of the next generation of American hardware startups.

Open hardware also carries a strategic dimension that goes beyond price. Because designs can be produced with distributed manufacturing technologies such as 3D printing, CNC milling, laser cutters, and open-source microcontrollers, scientific equipment can be fabricated locally and on demand within the United States. This insulates research supply chains from global disruptions, from pandemics to trade conflicts, and repatriates manufacturing capability that has migrated overseas. A federal grant that once could afford only a single proprietary instrument can instead fund an entire laboratory of open-source equivalents, accelerating discovery across any scientific field the equipment touches. Pearce frames these efficiencies as exactly the kind of fiscal discipline that cost-conscious administrations should champion, suggesting that agencies celebrate open hardware breakthroughs with press releases and awards rather than suppress them.

The letter closes with concrete demands directed at the Bureau Approving Officials. Pearce urges them to permit empirically grounded bills of materials and cost comparisons in manuscripts, to issue written guidance distinguishing comparative scientific analysis from endorsement, and to align manuscript review with agency public-access plans and the broader open-science expectations of the Office of Science and Technology Policy. The underlying principle, he argues, is simple: federal researchers should be allowed to report proudly how they are saving taxpayer money and providing open-source research and development to the American public. Whether the agencies respond by revising their review guidance or by continuing to redact economic data will signal how seriously the United States takes both the openness of its science and the competitiveness of the small manufacturers who depend on it.

The dispute is likely to resonate well beyond the federal bureaucracy. As open-source instruments, from syringe pumps to bioprinters, become mainstream tools in laboratories worldwide, the question of who may publish what about them has become a genuine constraint on the scientific record. Pearce’s letter, published as an editorial in HardwareX, places the issue squarely before the officials who control the clearance of government manuscripts, and before a research community that has watched open hardware deliver documented savings measured in the tens of millions of dollars. The stakes, as he frames them, extend to the integrity of peer review itself: a literature stripped of cost data is a literature that can no longer fully support replication, evaluation, or the efficient use of public funds.

Subject of Research: Open-source scientific hardware and federal censorship of cost data in U.S. government research publications

Article Title: An open letter to the Bureau Approving Officials of the United States government

Article References: Pearce, J. M. (2026). An open letter to the Bureau Approving Officials of the United States government. HardwareX, 27, Article e00825. https://doi.org/10.1016/j.ohx.2026.e00825

Image Credits: AI Generated

DOI: 10.1016/j.ohx.2026.e00825

Keywords: open-source hardware, HardwareX, scientific equipment, censorship, bills of materials, 3D printing, federal research policy, open science, cost savings, distributed manufacturing, small business, peer review

The team behind TinZr, led by Ludvik Alkhoury of the New Jersey Institute of Technology together with colleagues from Weill Cornell Medicine and collaborating institutions, set out to solve a persistent problem in wearable sensing research. Commercial microcontroller boards tend to force compromises: the Seeed XIAO ESP32-C3 is tiny and wireless but lacks a microSD card reader and a standardized connector for plug-and-play sensors; the Adafruit GEMMA v2 is featherweight but has no charging circuitry or storage; the popular Teensy 4.1 offers generous processing power and an SD card slot but no Wi-Fi or Bluetooth and a bulkier footprint. TinZr was engineered to combine all of these missing pieces in a single module sized for wearables.

At the heart of the platform sits Espressif’s ESP32-C3 microcontroller, a single-core RISC-V processor clocked at up to 160 MHz with native 2.4 GHz Wi-Fi and Bluetooth Low Energy 5.0 built in. The designers acknowledge that the chip offers fewer general-purpose input-output pins than larger development boards, but they argue the pin allocation was deliberately optimized for the interfaces that matter most in physiological sensing: digital, analog, I2C, SPI, and UART buses. An onboard QWIIC connector exposes the I2C bus along with power and ground, letting researchers snap on compatible sensors — optical, environmental, or electrophysiological — without touching a soldering iron.

Motion sensing is handled by an STMicroelectronics LSM6DS3TR-C inertial measurement unit, which pairs a three-axis accelerometer with a three-axis gyroscope in a single low-power package. The accelerometer can be configured for full-scale ranges up to plus or minus 16 g, while the gyroscope measures angular rates up to 2000 degrees per second, with output data rates reaching several kilohertz. In practice, the team envisions this motion data serving double duty: capturing physical activity directly and supporting artifact detection, so that movement contamination in physiological recordings can be identified and flagged during mobile experiments.

Power management, often the Achilles heel of battery-powered wearables, is entrusted to a Texas Instruments BQ24075RGTR charging chip with power-path management. This means the device can run from USB power while simultaneously charging its 150 mAh lithium-polymer battery, and can switch seamlessly to battery operation when unplugged — without interrupting a recording. The charge current is set to roughly 100 mA via an external resistor, matched to the small battery’s 0.67C charge rate, with safety timeouts and input current limits configured to stay comfortably within USB power budgets. The resistors can be swapped to accommodate larger batteries for longer studies.

Battery life figures vary dramatically by operating mode. In deep sleep with everything disabled, TinZr sips just 0.376 mA, enough for an estimated 16.6 days of standby on the standard battery. Active idle draws 14.8 mA, or about ten hours. Streaming inertial or physiological data over Bluetooth pushes consumption into the 41 to 61 mA range, yielding runtimes between roughly 2.5 and 3.7 hours depending on the sensor load — for example, 3.13 hours while streaming dual-wavelength photoplethysmography at 100 Hz, and 2.46 hours when acquiring ECG and PPG simultaneously at the highest tested rates. Wi-Fi transmission is the most power-hungry mode at 93 mA, draining the battery in under two hours. The platform also monitors its own battery voltage, enabling firmware-level low-battery warnings or automatic recording stops.

The validation experiments demonstrate why the platform matters for real research. In a multi-modal demonstration, TinZr simultaneously acquired a single-lead electrocardiogram from a MAX30001-based front-end and red and infrared photoplethysmographic signals from a MAX30102 optical sensor, streaming both over Bluetooth while packet timestamps and sample counters kept the mismatched sampling rates aligned for later analysis. The resulting ten-second recording showed crisp cardiac cycles with clearly distinguishable QRS complexes alongside pulsatile PPG waveforms. Separately, inertial recordings captured repetitive hand motion at metronome-controlled frequencies of 50 and 100 beats per minute, with the oscillation rate on the accelerometer and gyroscope traces tracking the tempo precisely.

Wireless reliability testing yielded striking results. A single TinZr transmitting inertial-style data at 100 Hz over Bluetooth recorded zero packet loss across 180-second trials at every distance tested, from under one foot up to twenty feet, both under direct line-of-sight and with a wooden door blocking the signal path. Signal strength, measured as RSSI, degraded with distance and obstruction as expected, falling to around -89 dBm at the far end, yet the connection held throughout. In a swarm-style test, five TinZr devices streamed simultaneously to a single laptop at 10 Hz each — again with zero packet loss across all conditions — demonstrating that coordinated multi-node deployments, from distributed body sensor networks to collaborative robotics, are practical with the stock hardware.

Perhaps the most consequential design decision is accessibility. TinZr is programmed through the Arduino ecosystem using an accompanying library called TinZrConnect, which ships with example sketches covering everything from basic button and LED control to a full communication framework in which multiple devices connect to a central PC hub over Wi-Fi for broadcast and individual addressing. Companion Python-based graphical interfaces — available both as source code and as installable executables — let researchers control recording start and stop and visualize data without writing firmware. The designers also provide 3D-printable enclosure files that house the board and battery in a wearable unit measuring just 29.5 by 29 by 20 millimeters, printable on an entry-level hobbyist 3D printer in PLA plastic.

The team is careful to note the platform’s limits: TinZr provides no medical-grade electrical isolation, is not certified for clinical use, and users connecting sensors to human subjects are responsible for ensuring the complete measurement chain meets applicable safety standards. Within research settings, however, the board’s combination of local storage, wireless flexibility, standardized sensor interfacing, and a $65 price point positions it as a serious alternative to commercial controllers for prototyping wearables, field data collection, and multi-device experiments. With hardware licensed under the CERN Open Hardware Licence and software under GPLv3, and all production files published on Zenodo with OSHWA certification, the barrier to building a custom multi-sensor wearable has arguably never been lower.

Subject of Research: An open-source ESP32-C3 microcontroller platform for multi-modal wearable physiological sensing and wireless data acquisition

Article Title: TinZr: A compact wireless ESP32-C3 platform for multi-modal physiological sensor integration and data acquisition

Article References: Alkhoury, L., Moore, T., Swissler, P., Hill, N. J., Shah, S. A., & Kam, M. (2026). TinZr: A compact wireless ESP32-C3 platform for multi-modal physiological sensor integration and data acquisition. HardwareX, 28, Article e00833. https://doi.org/10.1016/j.ohx.2026.e00833

Image Credits: AI Generated

DOI: 10.1016/j.ohx.2026.e00833

Keywords: TinZr, ESP32-C3, open-source hardware, wearable sensors, physiological monitoring, ECG, PPG, inertial measurement unit, Bluetooth Low Energy, data acquisition, HardwareX, battery-powered electronics

The timing of such a system is hardly accidental. Irrigated agriculture already accounts for approximately 70 percent of global freshwater withdrawals, while arable land continues to shrink under pressure from degradation and rapid urbanization. The Food and Agriculture Organization estimates that global agricultural production must increase by about 50 percent by 2050 relative to 2012 levels to feed a growing population. Controlled-environment agriculture, including vertical farming in urban buildings, has emerged as one strategy to raise productivity while cutting resource consumption, but its energy appetite has remained a persistent obstacle, with energy representing between 10 and 40 percent of total production costs in commercial greenhouses.

Among soilless cultivation techniques, aeroponics stands out for its extreme water efficiency. Unlike hydroponics, where roots sit submerged in nutrient solution, or aquaponics, which couples plant cultivation with fish farming, aeroponics suspends bare roots inside a closed chamber and sprays them with a fine nutrient mist. Reported water savings reach 90 to 98 percent compared with soil-based cultivation, while direct exposure to oxygen enhances root respiration and nutrient uptake. The technique also reduces exposure to soil-borne diseases, allows precise moisture control, and has even attracted attention from space agencies for food production under microgravity.

Yet aeroponics has a critical vulnerability: it depends on continuous electrical power. Because roots hang in air rather than water, a power outage can desiccate a crop within hours. Commercial vertical aeroponic towers, such as the Tower Garden FLEX, the Nutraponics Pro AeroTower, and the Agrotonomy Tower Farm system, all rely on grid electricity and proprietary designs, and none include integrated filtration to protect their misting nozzles. Prices range from $765 to $5,250 per unit, and academic prototypes published in the literature typically omit fabrication files, making them difficult or impossible to reproduce.

TOTEM was designed to close these gaps. The system stacks eight mechanically coupled modules, each housed in standard 20-centimeter-diameter PVC components: growth, reservoir, pump, filter, inlet-drainage, control, power, and solar. The growth module is a 1.5-meter PVC tower holding 24 net cups arranged in six staggered rows, with modified 45-degree elbow fittings angling each plant site to optimize light distribution. Inside the chamber, a vertical distribution pipe carries pressurized nutrient solution past 24 misting nozzles that atomize it into fine droplets directed at the suspended roots.

The hydraulic loop is deliberately simple and closed. A 12-volt DC diaphragm pump draws solution from the reservoir and pushes it through an AZUD Modular 100 mesh filter, which captures suspended particles before they can clog the nozzles, a failure mode that plagues many commercial systems. Filtered solution travels up the internal pipe, is atomized across the root zones, and the excess drains by gravity back into the reservoir for recirculation. During the basil trial, this closed loop required only about 54 liters of nutrient solution for 24 plants over the entire 55-day cycle, an estimated 0.041 liters per plant per day, far below reference values of roughly 0.6 liters per plant per day for protected agriculture and 12.6 liters for open-field cultivation.

At the system’s electronic core sits an ESP32-WROOM microcontroller mounted on a custom printed circuit board alongside an LM2596 voltage regulator, an FOD852 optocoupler, and an RAS1220M relay that switches the pump. A waterproof DS18B20 digital temperature sensor tracks conditions inside the growth chamber while a water-level sensor monitors the reservoir, enabling basic fault detection such as low-solution alerts. The microcontroller executes an intermittent irrigation schedule, in the validation trial running the pump for 0.5 minutes followed by 29.5 minutes of rest, equivalent to 48 activation cycles per day. Over Wi-Fi, the controller transmits data to a remote server that logs performance history and serves a web-based graphical user interface, allowing users to adjust irrigation parameters and monitor the system remotely, a capability none of the surveyed commercial towers offer.

Energy autonomy comes from a 50-watt polycrystalline solar panel mounted on a three-meter galvanized steel mast, angled at 24 degrees and oriented southward for maximum insolation. Power flows through a 40-amp MPPT charge controller into two 12-volt, 12-amp-hour rechargeable batteries wired in parallel, providing 288 watt-hours of nominal storage and roughly 122 watt-hours of usable energy at a conservative 50 percent depth of discharge. That corresponds to approximately 2.7 days of autonomous operation without any sunshine. The designers sized the array against the worst month of the year in La Paz, Baja California Sur, where December delivers only 3.9 peak sun hours per day; even with a photovoltaic derating factor of 0.70, the panel supplies an estimated 136.5 watt-hours daily, comfortably exceeding the calculated demand of 44.9 watt-hours after accounting for the pump’s 19.2 watt-hours, the continuously active microcontroller’s 19.0 watt-hours, and 85 percent system efficiency.

The validation experiment grew basil, a fast-growing crop prized in controlled-environment agriculture for its sensitivity to water availability, under uncontrolled shade-greenhouse conditions. After transplanting, formative pruning at 30 days promoted lateral branching, followed by a first harvest at 45 days and a final harvest at day 55. Sampled plants averaged 517.97 square centimeters of leaf area, 31.33 leaves, an 18.8-centimeter shoot length, and a mean relative water content of 82.18 percent, indicating that intermittent misting maintained adequate hydration throughout. Chamber temperatures fluctuated naturally between 14 and 38 degrees Celsius, and the system completed every programmed irrigation cycle without interruption across the full cultivation period.

The authors are candid about limitations. The final nutrient solution pH drifted to 7.39, above the mildly acidic range typically targeted in soilless production, and the team recommends adding calibrated pH and electrical conductivity sensors with closed-loop control in future iterations. The single-cycle trial demonstrated feasibility rather than long-term endurance, and the growth measurements from three plants provide descriptive data rather than statistically rigorous agronomic comparison. Still, the study’s principal contribution lies in its radical transparency: complete STEP CAD files for every module, circuit schematics, PCB layouts, ESP32 firmware in C++, and web interface code are released under CERN Open Hardware License v2-S and GNU General Public License v3, accompanied by an itemized bill of materials totaling $719.51. With a footprint of just 0.078 cubic meters, less than a ninth of comparable commercial towers, TOTEM makes off-grid aeroponic farming something a workshop, a school, or a resource-limited community can actually build, repair, and adapt for itself.

Subject of Research: An open-source, low-cost, solar-powered aeroponic vertical farming system for sustainable urban agriculture

Article Title: TOTEM: A low-cost solar-powered aeroponic system for vertical agriculture

Article References: Von Borstel, F. D., Villa-Medina, J. F., Nieto-Garibay, A., & Gutiérrez, J. (2026). TOTEM: A low-cost solar-powered aeroponic system for vertical agriculture. HardwareX, 28, Article e00838. https://doi.org/10.1016/j.ohx.2026.e00838

Image Credits: AI Generated

DOI: 10.1016/j.ohx.2026.e00838

Keywords: aeroponics, vertical farming, open-source hardware, solar power, urban agriculture, ESP32, water efficiency, controlled environment agriculture, basil cultivation, food security, IoT, sustainable agriculture