Currently, space-variable, capacitive multi-axis force/torque sensors have limited detection accuracy in the measurement of complex multi-axis loads owing to their inherent nonlinearity and coupling errors in the full range. The nonlinearity and coupling of the conventional capacitance differential equation were experimentally verified for a pre-developed space-variable capacitive six-axis force/torque sensing chip. An inverse capacitance differential decoupling equation was practically applied to the chip to suppress the inherent nonlinearity and coupling errors in the full range (2.5 N and 12.5 N & sdot; mm) under multi-axis loads. The results of complex multi-axis coupled loading tests align with the theoretical analysis. When the inverse decoupling equation is adopted, the maximum nonlinearities of 18.59% full scale (FS) and coupling errors of 254.1%FS for the conventional equation can be reduced to 1.05%FS and 10.90%FS, respectively. The efficient decoupling structure combined with the inverse capacitance differential equation can provide critical theoretical guidance for developing high-accuracy capacitive multi-axis force/torque sensors.

Abstract High-performance temperature sensors are critical components for emerging Internet-of-Things and biomedical-electronics platforms. However, simultaneously achieving high sensitivity, mechanical compliance, and user-defined integrability remains a formidable materials-and-device challenge. Here, we report a continuous graphene fiber (GF) thermocouple technology where multiple p–n thermocouples are created in situ along a single, unbroken fiber while preserving its structural integrity. By periodically modulating surface charge-transfer doping with polyethyleneimine (PEI) and FeCl 3 , we formed an array of ten p–n pairs that delivered an exceptional thermocouple sensitivity of 452.32 µV K −1 . The device retained ~97.8% of its initial sensitivity after 10,000 bending cycles at a 5-mm radius, confirming robustness under repeated mechanical deformation. When deployed on skin, the sensor tracked dynamic body temperature variations with a measurement error of 0.64%, validating its practical value for real-time, non-invasive health monitoring. These results establish all-carbon GF thermocouples as a high-precision and mechanically adaptable temperature-sensing platform for next-generation wearable electronics and personalized healthcare systems.

Real-time lactate monitoring is essential for clinical diagnostics, sports physiology, and industrial bioprocessing, yet conventional enzymatic sensors suffer from limited stability, narrow operational temperature range, and complex fabrication protocols. Herein, we report a robust non-enzymatic electrochemical sensor based on graphene fibers (GFs), featuring a GF/Au/Ni(OH)2 composite electrode with controllable structure fabricated via sequential electrodeposition. Systematic optimization of deposition parameters established a quantitative relationship between surface architecture and electrochemical response, revealing a critical trade-off between active site density and charge transport efficiency. The sensor achieved optimal performance when both Au and Ni(OH)2 were deposited for 900 s, exhibiting a high sensitivity of 1.24 mA mM−1 cm−2 and a remarkably broad operational temperature range of 0–100 °C. Moreover, the sensor demonstrates excellent repeatability, superior anti-interference capability against common electroactive species, and outstanding long-term durability with 97.8% response retention after 14 days. This work provides a rational design strategy for balancing catalytic activity and transport properties in metal–metal oxide composites, offering a reliable platform for advanced applications in next-generation wearable health-monitoring systems.

The advancement of high temperature resistant thin film strain sensors is crucial for detecting surface strain changes in aerospace turbine engines and launch vehicles. However, the strain sensitivity under high temperature thin film strain gauges is generally low, resulting in minimal resistance change under unit strain. In this regard, we proposed a thin film (thickness:similar to 500 nm) strain sensor, consisting of a composite structure including indium tin oxide with unconventional ratio (5-5 ITO, In2O3:SnO2 = 50:50 wt%) and Pt. Surprisingly, the strain sensor demonstrates ultrahigh sensitivity (gauge factor (GF) > 120, maximal GF = 178), rapid response time (0.12 s), as well as long cycling durability (10 h) under an operating temperature of 500 degrees C. The outstanding dynamic strain response and long-term temperature cycling stability of sensor originate from the micro-cracks in the sensitive film. The 5-5 ITO thin film produces island-like gaps with stress concentration in high-temperature environments, leading to a significant increase in resistance. Meanwhile, the top layer Pt structure covers the 5-5 ITO film, which aids in better recovery of micro-cracks, enhancing sensor repeatability and cycle durability. With its rapid response time, high sensitivity, and consistent performance at high temperatures, our strategy for this sensor holds great promise for applications in monitoring under extreme environment conditions.

Capacitive six-degree-of-freedom motion sensing technology has the advantages of fast response, high sensitivity, and excellent temperature independence. Widely applied to inertial measurement units and vector force sensors, it suffers from nonlinearity and crosstalk under the full range of multi-axis loads. This paper, based on a typical capacitive six-axis displacement/angle sensing structure consisting of multiple symmetrically arranged spacevariable comb and parallel capacitors, theoretically reveals the nonlinearity and crosstalk mechanism under the full range of multi-axis loads for the conventional capacitance differential equation. Two novel decoupling equations based on the fractional and inverse capacitance differential operations are proposed and derived to realize higher-accuracy decoupling detection. Moreover, the effects of full-range displacement, structural parameters, and parasitic capacitance on the nonlinearity and crosstalk of these three equations are discussed for further improvement. By adopting the inverse capacitance differential equation, the maximum nonlinearity and crosstalk errors of the conventional capacitance calculations can be reduced from 50.02 % and 603.2 %FS (Full Scale) to 0.29 % and 8.78 %FS, respectively. When the maximum full-range displacement is decreased from 2 to 0.25 mu m, the crosstalk error of 8.78 %FS can be further reduced to 1.49 %FS. The feasible condition circuits schemes for three decoupling equations, as well as the generation mechanism and suppression schemes for parasitic capacitance are discussed. A finite element simulation model based on the mechanical and electrical coupled multi-physic field is also established further to verify the theoretical model in the real world. The simulation results agree well the analytical results. The structure, decoupling equations, condition circuit schematic, and parameter analyses proposed in this paper can provide theoretical guidance for developing singlemass six-axis inertial measurement unit (IMU) and six-axis force/torque sensors.

3D printing has demonstrated irreplaceable advantages on rapid prototyping and flexible shaping of piezoelectric ceramic fabrication. However, several factors such as microstructure, densification, inferior electrical properties, and practical device design, significantly limit the applications of 3D‐printed piezoelectric ceramics. In this work, a method of utilizing the digital light processing technique to manufacture high‐performance piezoelectric Sm‐PMN‐PT ceramics with complex geometries for devices application is realized. The piezoelectric coefficient d 33 of 1285 pC N −1 is achieved, which represents the highest value reported to date among all 3D‐printed piezoelectric ceramics. Furthermore, an ultrasonic transducer annular array, which is challenging to achieve using traditional manufacture techniques, is designed and fabricated through 3D printing. The transducer demonstrates exceptional performance with a large bandwidth of 60%, a high peak‐to‐peak voltage of 952 mV, and improved imaging resolutions. Notably, the superior performance establishes a new benchmark in the achievable device level for 3D‐printed ultrasonic transducers. These results highlight the significant potential of 3D‐printed piezoelectric ceramics and complex structures on devices, showcasing their capability to fulfill specific needs and requirements.

One-dimensional nano-grating standard (ODNGS) is widely recognized as a crucial nanometric standard for metrological technology. However, achieving the ultratiny size of ODNGS with high consistent uniformity and low roughness by conventional processes such as the inductively coupled plasma (ICP) etching method presents a significant challenge in obtaining accurate calibration values. In this work, a 50-nm ODNGS with a conformal buffer layer (Al2O3) is successfully obtained, indicating outstanding stability and abrasion resistance. Remarkably, the introduction of hydrogen silsesquioxane (HSQ) and amorphous Al2O3 simultaneously guarantees an incredibly small expanded uncertainty (0.5 nm) and repeatability of the standard uniformity (less than 0.3 nm) in the grating dimensions. The I-V curves of ODNGS with an Al2O3 buffer layer at room temperature (RT) and 200 °C are depicted respectively to showcase the sustained favorable insulation properties. Notably, the nanostructure fluctuation, line edge roughness (LER) and line width roughness (LWR) of the standard can be decreased obviously by 64.1

With the development of intelligent and integrated electronic devices, leadless integrated sensors have a broad development. One of the most critical processes in TSV (Through Silicon Via) leadless packaging is Au-Au bonding, which the bond strength determines the success or failure of sensor preparation. In this research, the effect of the bonding temperature on the bonding strength was studied for the designed the temperature and pressure integrated sensor. To further increase the bonding strength, plasma treatment of the metal surface was applied. The influence of various plasma atmospheres and treatment times on the surface morphology, surface hydrophilicity, chemical state and the bonding rate were studied. And bonding interfaces under different bonding conditions were characterized. Finally, after 120 s of O2 plasma treatment and bonding for 1 hat 450 degrees C and 4000 mbar, the bond strength was increased by 68%, reaching 27 MPa, which enhances the feasibility of the preparation of temperature and pressure integrated sensors.

Metal oxides have been extensively investigated in non-enzymatic biosensors for detecting diabetes owing to their electrochemical catalytic properties and excellent stability. However, lower conductivity and catalytic activity are major obstacles to the commercialization of metal oxide-based non-enzymatic glucose sensors. Herein, we present a novel flexible nonenzymatic glucose sensor utilizing graphene fiber (GF)/Au/Ni(OH)2 composite fiber. The integration of GFs enables a significant uptake of sensing molecules due to its expansive surface area and high electron mobility, ultimately resulting in a decrease in the detection limit. Consequently, the incorporation of Ni(OH)2 provides abundant attachment sites by introducing Au atoms, thereby promoting electron migration and enhancing sensitivity and detection limits. An impressive sensitivity (1095.63 µA mM−1 cm−2) within the detection range (5 µM–2.2 mM) of the integrated GF/Au/Ni(OH)2 fiber is achieved, leading to an incredibly low detection limit (0.294 µM). Additionally, the outstanding repeatability, anti-interference properties, and flexibility of the GF/Au/Ni(OH)2 sensors are obtained as well. Our findings offer a novel method for constructing nano embossments on GFs to achieve superior glucose detection capabilities in the field of wearable electronics in the future.

To develop a metal-bonded diamond tool that does not require frequent dressing during grinding, a novel glass fibre metal-bonded porous diamond block is proposed. The effect of the content percentage and particle size of polymethyl methacrylate (PMMA) pore formers on the porosity of porous diamond blocks was investigated. The Vickers hardness and bending strength of the porous blocks with and without diamonds were tested. Wear tests were performed on the porous diamond blocks. The results show that an increase in the PMMA content (1.75-9.45 wt%) caused an increase in the porosity (2.8 %-22.9 %) and a decrease in the bending strength (8.6 %-71.9 %) and Vickers hardness (22.1 %-54.3 %), compared to those of the blocks without PMMA. An increase of PMMA size (20-40 mu m diameter) caused an increase in the porosity (2 %-11.6 %), and a decrease in the bending strength (34.1 %-42.7 %) and Vickers hardness (23.7 %, 40.5 %), compared to those of the blocks without PMMA. However, excessively large PMMA particles (50-70 mu m diameter) caused a decrease in the porosity and an increase in the bending strength and Vickers hardness. Increasing the porosity of the diamond blocks appropriately can reduce the need for frequent dressing and enhance the SiC removal rate. However, excessive porosity tends to accelerate diamond wear, leading to a decrease in the SiC removal rate.

Al2O3/ZnO nanolaminates are promising for thin-film transistors and photoluminescence applications. In this work, the thermal induced interface changes of Al2O3/ZnO nanolaminates were studied as a function of the in site deposition temperature and rapid post-annealing temperature. The Al2O3/ZnO nanolaminates were grown by atomic layer deposition system at 80 degrees C, 120 degrees C, and 250 degrees C, and further post-annealed in a rapid thermal processing (RTP) furnace at 600 degrees C, 700 degrees C, and 800 degrees C for 10 min, separately. Then the microstructures, interfacial diffusion and solid-phase reactions of the Al2O3/ZnO nanolayers were systematically investigated by X-ray diffraction (XRD), scanning electron microscopy (SEM) and high-resolution transmission electron microscopy (HR-TEM). The results show that the in situ growth temperature directly affects the crystallinity and selective orientation of the ZnO interlayers, which further induce the ZnO interlayers to undergo completely different interfacial diffusion and solid-phase reactions during the rapid post-annealing processing. The films grown at 80 degrees C were close to amorphous, while those grown at 120 degrees C had a distinctly dominant orientation and exhibited better crystallization at 250 degrees C. The presence of the ZnAl2O4 grains indicates the solid-phase reactions have occurred on the ZnO/Al2O3 interface during the rapid post-annealing at 700 degrees C or above.

3D printing stereolithography (SL) technique were successfully applied in the preparation of <001>-textured 0.71Pb(Mg1/3Nb2/3)O-3-0.29PbTiO(3) (PMN-29PT) ceramics in this work. The as-sintered textured ceramics show obvious grain orientation control effects, and the relative density reaches 93% of the theoretical density. The obtained ceramics demonstrate typical dielectric/ferroelectric/piezoelectric properties, enabling the device applications. The ultrasonic transducer with the center frequency of 6.7 MHz and the -6 dB bandwidth of 25% are designed and prepared based on the obtained textured ceramic. This work signifies the great potential of 3D printing SL technology on the fabrication of piezoelectric ceramic elements for advanced applications.

AbstractMiniaturized six-axis force/torque sensors have potential applications in robotic tactile sensing, minimally invasive surgery, and other narrow operating spaces, where currently available commercial sensors cannot meet the requirements because of their large size. In this study, a silicon-based capacitive six-axis force/torque sensing chip with a small size of 9.3 × 9.3 × 0.98 mm was designed, fabricated, and tested. A sandwich decoupling structure with a symmetrical layered arrangement of S-shaped beams, comb capacitors, and parallel capacitors was employed. A decoupling theory considering eccentricity and nonlinear effects was derived to realize low axial crosstalk. The proposed S-shaped beams achieved a large measurement range through stress optimization. The results of a coupled multiphysics field finite-element simulation agreed well with those of theoretical analyses. The test results show that the proposed sensing chip can detect six-axis force/torque separately, with all crosstalk errors less than 2.59%FS. Its force and torque measurement ranges can reach as much as 2.5 N and 12.5 N·mm, respectively. The sensing chip also has high sensitivities of 0.52 pF/N and 0.27 pF/(N·mm) for force and torque detection, respectively.

Stress tolerance plays a vital role in ensuring the effectiveness of piezoresistive sensing films used in flexible pressure sensors. However, existing methods for enhancing stress tolerance employ dome-shaped, wrinkle-shaped, and pyramidal-shaped microstructures in intricate molding and demolding processes, which introduce significant fabrication challenges and limit the sensing performance. To address these shortcomings, this paper presents periodic microslits in a sensing film made of multiwalled carbon nanotubes and polydimethylsiloxane to realize ultrahigh stress tolerance with a theoretical maximum of 2.477 MPa and a sensitivity of 18.092 kPa −1 . The periodic microslits permit extensive deformation under high pressure ( e.g ., 400 kPa) to widen the detection range. Moreover, the periodic microslits also enhance the sensitivity based on simultaneously exhibiting multiple synapses within the sensing interface and between the periodic sensing cells. The proposed solution is verified by experiments using sensors based on the microslit strategy for wind direction detection, robot movement sensing, and human health monitoring. In these experiments, vehicle load detection is achieved for ultrahigh pressure sensing under an ultrahigh pressure of over 400 kPa and a ratio of the contact area to the total area of 32.74%. The results indicate that the proposed microslit strategy can achieve ultrahigh stress tolerance while simplifying the fabrication complexity of preparing microstructure sensing films.

Flexible and compact sensors for collecting essential information from the environment are showing growing importance in robotic perception. In particular, flexible, multimodal, and low-form-factor sensors are among the major needs. In this article, a new sensor based on flexible printed circuits and flexible pressure-sensitive material was fabricated and characterized. To minimize fabrication complexity and improve reliability, the presented sensor builds on an established technology and a simple fabrication process. A layered device that can measure temperature, pressure, and surface material relative permittivity was designed, modeled, and tested. With a response time of 0.3 s, the sensor has high linearity in temperature measurement in the range of -30 degrees C to 120 degrees C. The sensor maintained its structural integrity and functional performance after undergoing a cumulative 10 h of exposure at 120 degrees C, demonstrating its resilience to harsh environments. In pressure measurement, the sensor monitors pressure from 0 to 65 kPa with a response time of 0.01 s, even after being overloaded approximately 50 times above the measuring range. In addition to tactile sensing, the sensor is integrated with the material recognition function based on relative permittivity measurement. This integration allows robots to recognize materials with relative permittivity between 1 and 9.3. Such functionality not only improves the adaptability of robots in various environments but also significantly augments their operational intelligence by providing crucial information about object materials, which is essential for complex task executions. Finally, the sensor was installed on a robotic gripper to simultaneously measure temperature, pressure, and material relative permittivity of surfaces. The flexible and lightweight sensor with its easy integration into robotic manipulators is promising for applications in intelligent sorting, smart factories, and intelligent prosthetics.

Heat-assisted magnetic anisotropy engineering has been successfully used in selective magnetic writing and microwave amplification due to a large interfacial thermal resistance between the MgO barrier and the adjacent ferromagnetic layers. However, in spin-orbit torque devices, the writing current does not flow through the tunnel barrier, resulting in a negligible heating effect due to efficient heat dissipation. Here, we report a dramatically reduced switching current density of similar to 2.59 MA/cm(2) in flexible spin-orbit torque heterostructures, indicating a 98% decrease in writing energy consumption compared with that on a silicon substrate. The reduced driving current density is enabled by the dramatically decreased magnetic anisotropy due to Joule dissipation and the lower thermal conductivity of the flexible substrate. The large magnetic anisotropy could be fully recovered after the impulse, indicating retained high stability. These results pave the way for flexible spintronics with the otherwise incompatible advantages of low power consumption and high stability.

Traditional current-driven spintronics is limited by localized heating issues and large energy consumption, restricting their data storage density and operation speed. Meanwhile, voltage-driven spintronics with much lower energy dissipation also suffers from charge-induced interfacial corrosion. Thereby finding a novel way of tuning ferromagnetism is crucial for spintronics with energy-saving and good reliability. Here, a visible light tuning of interfacial exchange interaction via photoelectron doping into synthetic antiferromagnetic heterostructure of CoFeB/Cu/CoFeB/PN Si substrate is demonstrated. Then, a complete, reversible magnetism switching between antiferromagnetic (AFM) and ferromagnetic (FM) states with visible light on and off is realized. Moreover, a visible light control of 180° deterministic magnetization switching with a tiny magnetic bias field is achieved. The magnetic optical Kerr effect results further reveal the magnetic domain switching pathway between AFM and FM domains. The first-principle calculations conclude that the photoelectrons fill in the unoccupied band and raise the Fermi energy, which increases the exchange interaction. Lastly, a prototype device with visible light control of two states switching with a 0.35% giant magnetoresistance ratio change (maximal 0.4%), paving the way toward fast, compact, and energy-efficient solar-driven memories is fabricated.

Spin waves are considered to be an alternative carrier with great promise for information sensing. The feasible excitation and low-power manipulation of spin waves still remain a challenge. In this regard, natural light enablings spin-wave tunability in Co60 Al40 -alloyed film is investigated. A reversible shift of the critical angle (from 81° in the dark to 83° under illumination) of the body spin-wave is achieved successfully Meanwhile, an eye-catching shift (817 Oe) of the ferromagnetic resonance (FMR) field is obtained optically, leading to changes in magnetic anisotropy. Based on the modified Puszkarski's surface inhomogeneity model, the control of spin-wave resonance (SWR) by sunlight can be understood by an effective photoelectron-doping-induced change of the surface magnetic anisotropy. Furthermore, the body spin wave is modulated stably with natural light illumination, confirming a non-volatile, reversible switching behavior. This work has both practical and theoretical importance for developing future sunlight-tunable magnonics/spintronics devices.

The emerging market of wearable devices for tracking and positioning requires the development of highly flexible magnetic sensors. Due to the stable magnetoresistance ratio and simple fabrication process, sensors based on the anisotropic magnetoresistance (AMR) effect have been proposed as promising candidates. However, the stability of AMR sensors under different bending situations has rarely been investigated. In this work, we proposed a flexible AMR magnetic sensor deposited on an ultra-thin Kapton substrate, which exhibits excellent anti-fatigue behavior at different bending curvatures ranging from 1/3 to 1/10 mm(-1). Experimental results show that the sensitivity of our proposed flexible AMR sensor remains as high as 0.25 Oe(-1) after being bent 500 times, showing promising potential for application in wearable electronic devices.

Integrated periodic structure reference materials are crucial for calibration in optical instruments and micro-computed tomography (micro-CT), yet they face limitations concerning a restricted measurement range, a single pattern type, and a single calibration parameter. In this study, we address these challenges by developing integrated periodic structure reference materials with an expanded measurement range, diverse pattern types, and multiple calibration parameters through a combination of photolithography and inductively coupled plasma (ICP) etching process. These reference materials facilitate high-efficiency and multi-value calibration, finding applications in the calibration of optical instruments and micro-CT systems. The simulations were conducted using MATLAB (R2022b) to examine the structure-morphology changes during the single-step ICP etching process. The variation rules governing line widths, periods, etching depths, and side wall verticality in integrated periodic structure reference materials were thoroughly evaluated. Linewidths were accurately extracted utilizing an advanced image processing algorithm, while average period values were determined through the precise Fast Fourier Transform method. The experimental results demonstrate that the relative errors of line widths do not exceed 17.5%, and the relative errors of periods do not exceed 1.5%. Furthermore, precise control of the etching depth was achieved, ranging from 30 to 60 μm for grids with line widths 2–20 μm. The side wall verticality exhibited remarkable consistency with an angle of 90° ± 0.8°, and its relative error was found to be less than 0.9%.