Lunar dust adhesion poses a significant challenge to exploration equipment. Herein, we develop a multifunctional coating designed for passive dust protection by fabricating a polydimethylsiloxane (PDMS) composite doped with micron silver powder (Ag), multi-walled carbon nanotubes (MWCNTs), and hydrophobic silicon dioxide (SiO2). This material integrates a micro-nano rough surface, high electrical conductivity, and self-healing properties into a single synergistic system. The constructed "Ag/MWCNT" dual-conductive network achieves a low sheet resistance of similar to 100 Omega/sq., an order-of-magnitude reduction compared to coatings with a single conductive filler. The coating demonstrates durable, thermally induced self-healing (>= 8 cycles) and high abrasion resistance, retaining a contact angle of similar to 140 degrees after 40 cycles. Atomic force microscopy (AFM) probe tests with simulated dust revealed a minimal adhesion force of 24.88 nN, which is significantly lower than on common spacecraft aluminum materials. This performance, coupled with excellent dust repellency in flip tests, establishes this self-healing conductive coating as a highly effective solution for protecting equipment in the lunar environment.

Abstract Despite the efficacy of the methylammonium chloride (MACl) additive strategy in stabilizing the α-phase of formamidine-based perovskite materials, a persistent and formidable challenge from the irreversible deprotonation of MA + cation still bothers the fabrication of satisfactory formamidine (FA)-based perovskite photosensitive layers, thereby hindering the performance improvement of resultant perovskite solar cells. To confront this obstacle, numerous methodologies have been proposed and demonstrated their potential, particularly those leveraging additives enriched with carboxylic acid functional groups (-COOH). However, these approaches remain inherently flawed due to the deleterious competitive proton transfer from hydrogen iodide (HI) to the excess -COO - species, which undermines the integrity of the entire strategy. Herein, an innovative methyl trifluoroacetate (MTFA)-assisted technique is pioneer conducted to control the competitive proton-transfer through its stepwise hydrolysis reaction and the gentle release of -COOH derived from trifluoroacetic acid (TFA) byproduct. By this way, the perovskite precursor solution deprotonation is suppressed and the shelf life of corresponding perovskite precursor solution is greatly prolonged to over 22 days. Concurrently, the robust affinity of -COOCH 3 or byproduct -COOH groups toward uncoordinated Pb 2+ has also been proven to enable the fine-tuning of perovskite crystallization dynamic, while the residual CF 3 COO - species distributed in the buried interface of perovskite are considered to offer an additional improvement in film carrier behavior via the halogen vacancies passivation. Consequently, high-quality perovskite films with conspicuous crystalline structure, surface morphology and carrier characteristic were obtained, achieving a champion device fabricated from 22 days aging perovskite precursor solution (PPS) with a power conversion efficiency of 26.35% and retaining 94.75% of its initial efficiency after 1464 h of humidity exposure.

The precise manipulation of micro-scale targets is a foundational technology driving advancements in biomedical engineering, clinical diagnostics, and micro-manufacturing. Here, we present a multifunctional acoustic valve microrobotic system capable of the precise manipulation of cells and microorganisms. The focused surface acoustic wave transducers are utilized to form valve-like potential wells, thereby enabling stable entrapment and transportation of micro targets. Based on this ability, it can further realize direct sorting and enrichment, by sweeping the acoustic field through the targeted regions. Experimental results demonstrate that this platform can achieve high-speed manipulation exceeding 1000 μm s-1, and can achieve sub-10 μm navigation accuracy. Furthermore, it supports highly efficient sorting and enrichment, delivering a target recovery rate of over 90% and an enrichment ratio of 5 to 10 fold in a single cycle. We verified the system's biocompatibility through thermal stability experiments and cell viability assays, and successfully applied the acoustically enriched microalgae to the photocatalytic degradation of tetracycline. Collectively, this versatile and highly adaptable acoustic platform provides a powerful tool for complex micro-manipulation, and has the potential to be used in cutting-edge applications such as cell analysis and biological assembly.

To validate the effectiveness of the grooved diaphragm with back peninsulas and trenches (GDPT) and the radial basis function neural network (RBFNN)-based dimension generator in the development of a 1 kPa piezoresistive micropressure sensor, this paper presents a comprehensive investigation into the design, fabrication, and characterization of the anticipative sensor prototype. The GDPT achieves favorable sensing stress and reduced deflection, enabling a favorable trade-off between sensitivity and nonlinearity; the RBFNN-based generator efficiently determines practicable dimensions for the complex structure, offering a significant improvement over the conventional trial-and-error process. Characterization results demonstrate that the fabricated sensor achieves sensitivity of 13.01 mV/(V·kPa) and nonlinearity of 0.26% FS within the pressure range of 0–1 kPa, in good agreement with the preset design target. This work verifies the validity of the proposed approach and offers a holistic methodology for developing high-performance piezoresistive sensors.

Recently, biomimetic porous structures have garnered significant attention due to promising application in thermal management systems. However, flexible design and performance optimization remain challenges to the in-depth investigation of cold plate heat transfer enhancement. Triply Periodic Minimal Surfaces (TPMS), mathematically defined as implicit surfaces with minimal mean curvature, exhibit superior structure interconnectivity and a high surface-area-to-volume ratio, making TPMS structures particularly promising for advanced fluid cooling applications. In cold plate design, the geometric configuration determines the fluid flow direction, which in turn strongly influences the heat transfer pathway. This study advances the design and optimization of TPMS cold plates, with particular attention to Gyroid and Diamond structures. A high-degree-of-freedom modelling framework is developed to generate TPMS variants with different periods and shell thicknesses using a small set of control parameters. The qualitative and quantitative relationships among geometric characteristics are systematically investigated. A material interpolation model is constructed to realize meshless numerical calculations and validated for accuracy. Subsequently, a multi-objective optimization problem is formulated based on the non-gradient NSGA-II algorithm, targeting both the average surface temperature of the heating source (overall thermal performance) and standard deviation of temperature (temperature uniformity). The adaptively optimized designs reveal that employing a small and uniform period along the mainstream direction enhances overall heat transfer performance, whereas a gradually decreasing period contributes to improved temperature uniformity. Besides, a gradually increasing shell thickness benefits both thermal metrics. Compared to the regular TPMS designs, the optimized Gyroid structure achieved a maximum reduction of 7.80 K (2.24%) in mean temperature and 3.78 K (32.98%) in standard deviation of temperature, whereas the optimized Diamond structures yielded respective reductions of 1.86 K (0.55%) and 5.09 K (46.53%). The proposed method effectively reduces the geometrical modelling and numerical analysis costs of flexible design and performance optimization for TPMS structures, and further extends their application potential.

Highlights PVDF thin film array sensing module proposed for wheat cleaning loss monitoring. 4×2 PVDF sensor array reduces signal aliasing by 0.48%. Accuracy error <4% achieved through vertical array layout. Flexible design enables easy sensor replacement. Abstract. PVDF flexible piezoelectric sensors have the advantages of a simple structure and fast response speed, and have broad application prospects in the field of grain cleaning loss monitoring. However, most current cleaning loss sensors still face the problems of low sensitivity, difficulty in disassembly and assembly, and large cleaning loss monitoring errors. Based on this, this paper proposes a vertically distributed PVDF flexible thin film sensing array module for cleaning loss. The performance of the PVDF sensor unit was first characterized, and the difference in signal characteristics between grains and short straws was studied. When grains collide with a sensing array, the voltage distribution among the sensing units was recorded, and the accuracy of cleaning loss monitoring for sensing modules was tested. The influence of array layout and installation method on accuracy was studied by comparing the sensing results. In addition, a signal conditioning circuit for the sensor, which counts the signals through an MCU, was designed. The test results show that the accuracy error of the cleaning loss monitored by the sensor module proposed in this study is less than 4%, which is 0.48% lower than previous reported studies. Keywords: Combine harvesters, Cleaning losses, Precision agriculture, PVDF thin film, Sensors.

Stretchable pressure sensors have exceptional adaptability for conformal-attachment monitoring on curved biological surfaces, enabling mechanosensing applications such as patellofemoral motion monitoring. However, conventional soft pressure sensors face challenges from off-axis deformations (eg, bending or stretching), compromising signal fidelity and limited adaptability to new subjects in posture prediction. Here, a stretchable iontronic pressure sensor with off-axis strain-insensitivity is presented. The sensor leverages the electric double-layer capacitive sensing mechanisms to achieve superior sensitivity (18.174 kPa(-1)) while maintaining minimal inter-unit crosstalk (<1% signal interference) in the array. Serving as the mechanical-strain buffers, the microcavity spacer and ultra-stretchable electrode mitigate passive strain concentration to make the sensor mechanically resilient against both bending (up to 0.67 cm(-1) curvature) and tensile (<= 40% strain) deformations, respectively. The stretchable sensor array continuously monitors dynamic pressure over curved patellofemoral skin during knee motions. Via an effective transfer learning algorithm, continuous and nonlinear 16D pressure data achieves >95% classification accuracy corresponding to the subjects' patellofemoral motion, which also adapts data from a new subject to predict the unknown posture. The off-axis-strain invariant and stretchable pressure sensor with transfer learning-based adaptive capability holds potential for knee injury evaluation, dynamic rehabilitation, and real-time biomechanical analysis.

Despite the dazzling progress since the emergence of perovskite solar cells (PSCs), a significant ideal-reality discrepancy with respect to the open-circuit voltage (VOC) still reminds the primarily weak parameter, inducing the limited power conversion efficiency (PCE) relative to its Shockley-Queisser theoretical limit. Eliminating the detrimental non-radiative recombination centers enriched at the surface/grain boundaries of perovskite films is generally regarded as the key approaches to bridge this gap. Herein, a perovskite crystallization dynamic regulation template is conducted to ensure the realization of both rapid nucleation and suppressed crystal growth through the synchronous incorporation of SCN- and volatility NH4 + ligands. Thereby promoting the formation of high-quality perovskite films with enlarged grain size, superior crystallinity, ordered surface texture and compensated residual strain. Notably, residual SCN- ligands detected in the buried interface of perovskite films is also inclined to serves as an interface passivators. In conjunction with the above analysis, desired perovskite films with decreased defect density and suppressed non-radiative recombination are acquired for the NH4SCN sample, leading to impressive power conversion efficiencies of 26.13% with one of the lowest VOC losses among all reported p-i-n structure PSCs, reaching 96.13% of their theoretical VOC limit.

Flexible piezoresistive sensors that offer both high sensitivity and a broad linear detection range are highly desirable for wearable health monitoring, as they facilitate simplified circuit design and enable accurate detection of subtle physiological signals. However, existing sensors typically encounter an intrinsic trade-off between sensitivity and linearity, primarily due to structural stiffening under increasing pressure. Here, a flexible piezoresistive pressure sensor featuring dual-graded microstructures (DGM) is reported, formed by embedding multi-walled carbon nanotubes (MWCNTs) into a thermoplastic polyurethane matrix. Leveraging the synergistic effects of progressive structural deformation and MWCNTs-induced tunneling conduction, the sensor achieves a high sensitivity of 69.8 kPa⁻¹ and a broad linear sensing range up to 300 kPa (R2 ≈ 0.998). The sensor also exhibits rapid response-relaxation time (totaling 5 ms), stable high-frequency detection up to 200 Hz, and good stability over 5 000 repeated loading cycles. Demonstrations in physiological monitoring confirm the sensor's capability to precisely capture detailed radial pulse waveforms, respiratory rhythms, and subtle heartbeat-induced vibrations. Both a scalable, cost-effective structural fabrication and good overall sensing performance establish the DGM-based sensor as a promising candidate for advanced wearable healthcare monitoring devices.

The emerging flexible iontronic sensing (FITS) technology has introduced a novel modality for tactile perception, mimicking the topological structure of human skin while providing a viable strategy for seamless integration with biological systems. With research progress, FITS has evolved from focusing on performance optimization and structural enhancement to a new phase of integration and intelligence, positioning it as a promising candidate for next-generation wearable devices. Therefore, a review from the perspective of technological development trends is essential to fully understand the current state and future potential of FITS devices. In this review, we examine the latest advancements in FITS. We begin by examining the sensing mechanisms of FITS, summarizing research progress in material selection, structural design, and the fabrication of active and electrode layers, while also analysing the challenges and bottlenecks faced by different segments in this field. Next, integrated systems based on FITS devices are reviewed, highlighting their applications in human-machine interaction, healthcare, and environmental monitoring. Additionally, the integration of artificial intelligence into FITS is explored, focusing on optimizing front-end device design and improving the processing and utilization of back-end data. Finally, building on existing research, future challenges for FITS devices are identified and potential solutions are proposed.

Lattice structures have drawn significant interest owing to their exceptional mechanical properties, e.g. lightweight, strong, and tough performance. Here, inspired by the biostructure of the beetle elytra, a new tube-plate hybrid lattice structure (TPHL) is proposed. The TPHL lattice specimens are fabricated by the selective laser melting (SLM) technique, and the compression mechanical properties are analysed. The compression responses of the TPHL are compared with conventional Octet (OCT), simple cubic (SC), and simple tube (TUBE) lattice structures. An optimisation model is developed to further improve the energy absorption characteristics. The TPHL lattice structure exhibits maximum 50.30% (relative density is 0.10) higher specific energy absorption (SEA) than SC pure plate lattice, and maximum 42.25% $\lpar \bar{\rho } = 0.18\rpar$(rho=0.18) higher specific energy absorption than OCT pure plate lattice. The novel lattice structure shows the transition of the deformation modes and dual energy-absorbing plateaus. The enhanced energy absorption is mainly ascribed to the interaction of the cross-assembled tubes and plates in the second plateau. Besides, the configuration of the TPHL lattice structure after optimisation demonstrates significantly enhanced energy absorption characteristics. The bioinspired design strategy and potential mechanical mechanism provide useful guidance for designing lattice structures with exceptional energy absorption properties.

This paper presents the development of a piezo-driven calibration device for force sensors. A piezoelectric actuator is used to generate the original driving force, and a two-stage hybrid displacement amplifier can adjust the driving displacement and loaded force into the desirable range for sensor calibration. A force tester is set on the output end of the amplifier to load and monitor the calibration force. The features of the displacement amplifier and force tester are theoretically modeled and verified by finite element analysis (FEA). A laboratorial prototype is realized by assembling the commercial piezoelectric actuator into the displacement amplifier fabricated using wire electrical discharge machining and adhering metallic strain gauge onto the sensing beam of the force tester. The experimental results demonstrate that the device can output a displacement of 666 μm under the 130 V driving voltage and successfully realize the 0.2 N-range sensor calibration with the error of 0.56

Controllable crystallization dynamics and manageable residual strain within the perovskite films are challenging yet indispensable aspects of assembling high-performance perovskite solar cells. This is particularly critical for FA-based organic-inorganic hybrid perovskite materials as their complex crystallization process and thermodynamically instability at temperatures below 150 degrees C. Therefore, the development of an unprecedented and feasible approach that can simultaneously modulate both of these predicaments is currently highly demanded. In this work, DMA+ with a larger ionic radius was employed to delay the formation of both alpha-phase and delta-phase perovskite in precast films, thereby reducing their nucleation density. Additionally, the introduction of DMA+ can also effectively mitigate structure distortion in the Pb-I framework caused by harmful residual strain, which arises from mismatched cationic size and thermal expansivity. Overall, significantly improves both the crystalline properties and charge carrier dynamics of the target sample, consequently leading to a remarkable enhancement in their phase stability. Ultimately, we achieved an optimized device with greatly enhanced efficiency (25.60 %) along with one of the highest VOC of 1.19 V. The champion DMAI treated device is also constructed as a flexible perovskite solar cell (F-PSC) with efficiency of 22.34 %. Notably, even after undergoing 1600 h of moisture aging and 1000 h of thermal aging without encapsulation, the target device still maintained over 85 % of its initial performance.

A novel cooperative regulatory strategy is proposed in this work to optimize the crystallization dynamics of Formamidinium (FA)-based perovskite materials, which is achieved by meticulously incorporating the organic molecule guanidinium (GA+) and the high boiling point organic solvents N-Methyl-2-Pyrrolidone (NMP) into the perovskite precursor solution synergistically. This findings indicated that the GA+ doping strategy (G-DS) is toward to inhibits the formation of alpha-phase perovskite crystals owing to its larger ionic radius, thereby promoting the formation of perovskite films with enlarged grain size. Simultaneously, the NMP-doping strategy (N-DS) has assisted controllable crystallization dynamics in as-cast films by optimizing nucleation density and crystal growth rate through a delayed supersaturated environment induced re-dissolution function. Briefly, it can assume that the crystallization dynamics dual modulation strategy enables the realization of high-quality perovskite film with micro-meter sized perovskite grain, appropriate internal strain and a compact, dense surface texture. The optimized films therefore exhibits powerful exciton separation energy, suppressed charge carrier recombination and reduces series resistance, leading to a remarkable champion power conversion efficiency (PCE) of 25.38% and exceptional reliability, retaining 93.09% of their initial PCE after storage the unencapsulated devices in a moisture-rich environment for 2160 h.

AbstractFlexible pressure sensors play a significant role in wearable devices and electronic skin. Iontronic pressure sensors with high sensitivity, wide measurement range, and high resolution can meet requirements. Based on the significant deformation characteristics of alveoli to improve compressibility, and the ability of the arch to disperse vertical pressure into horizontal thrust to increase contact area, a graded hollow ball arch (GHBA) microstructure is proposed, greatly improving sensitivity. The fabrication of GHBA ingeniously employs a double‐sided structure. One side uses mold casting to create convex structures, while the other utilizes the evaporation of moisture during the curing process to form concave structures. At the same time, a novel side‐by‐side package structure is proposed, ensuring pressure on flexible substrate is maximally transferred to the GHBA microstructure. Within the range of 0.2 Pa–300 kPa, the iontronic pressure sensor achieves a maximum sensitivity of 10 420.8 kPa−1, pressure resolution of 0.1% under the pressure of 100 kPa, and rapid response/recovery time of 40/35 ms. In wearable devices, it is capable of monitoring dumbbell curl exercises and wirelessly correcting sitting positions. In electronic skin, it can non‐contactly detect the location of the wind source and achieve object classification prediction when combined with the CNN model.

Soft piezocapacitive sensor, owing to its simple assembly and low power consumption, draws intensive interests for physiological monitoring. However, crosstalk between proximity sensing units and limited mechanically stretching suppressed its practical application for conventional capacitive sensor array. Here we report a stretchable iontronic pressure sensor (SIPS) array with low proximate crosstalk for epidermal monitoring. Benefiting from electric double layer (EDL) capacitance effect between robust aramid nanofiber (ANF) /MXene (Ti3C2Tx) composite electrode and ionic film, the SIPS exhibits a high sensitivity up to 521.69 kPa−1, low limit of detection (0.22 Pa), broad linear sensing range (200 kPa) and rapid response time (17 ms) as well as long-term stable working durability for 10,000 cycles. The serpentine island bridge structure enables the SIPS array to stretch up to 40%, allowing pulse and grip monitoring of a bent wrist and finger, respectively, through processing circuits. This demonstrates the promising application prospects in vital physiological monitoring.

The instrumented nanoindentation technique has been widely used to measure the tensile properties of various materials, for its simple specimen preparation and nearly nondestructive testing processes. In this paper, a novel inverse method is established for measuring the elastoplastic properties of Al 2024 alloy. The grid indentation experiments are performed on Al 2024 material. The obtained experimental load-displacement (P-h) data exhibit obvious scatter characteristics. The artificial neural network (ANN) model with tunable hyper-parameters is adopted to establish the forward relationship between elastoplastic parameters and indentation load-displacement snapshot. An objective function for quantifying the error norm between predicted and experimental P-h snapshots is established. The parameter identification problem is solved using the "interior-point" constraint optimization algorithm.. The identified material properties show good agreement with the tensile data, and the error values are -8.66% for elastic modulus, 1.08% for yield stress, and 6.90% for hardening exponent. The sensitivity of numerical results to experimental uncertainty is analyzed, and the error bound of experimental data is determined. The results of sensitivity analysis indicate that the proposed inverse method in the work is very effective and reliable.

Flexible three-dimensional (3D) force sensors have been extensively investigated in the field of robotics due to their ability to provide feedback information from multiple directions. However, the development of flexible 3D force sensors with high sensitivity and decoupling capabilities remains a significant challenge, hindering the ability of robots to perceive their external environment. In this letter, we present a novel flexible 3D force iontronic sensor (FTIS) that utilizes ionic materials with micro-pyramidal structures and a backpropagation (BP) neural network method based on deep learning. The FTIS exhibits outstanding sensitivity, with over 8000 $\text{N}^{-{1}}$ in the normal direction and over 4000 $\text{N}^{-{1}}$ in the shear direction, and has a rapid response time of 27-ms. Additionally, it demonstrated stable working durability, with over 8000 cycles without signal delay. To validate the utility of the sensor, we integrated it as a machine-sensing interface on a mechanical claw to measure changes in forces in the triaxial direction. Our design concept has the potential to advance the development of multidimensional force sensors in the future.

During landing, the plume from the lander erodes the regolith on the lunar surface, thus destroying the nature of this surface. Landing also provides an opportunity to extract the mechanical properties of the lunar regolith in situ and to study wind erosion on airless bodies such as the Moon. Our goal in this study is to quantify the interparticle force of the lunar regolith, the erosion depth, and other parameters and to test the reliability of the plume erosion model. The erosion depth provides the necessary reference information for the precise interpretation of scientific results obtained from returned samples. We measure the total mass of the lunar regolith mobilized by the plume during the Moon landing. This information is also helpful for future lunar missions. With high-quality data from the Chang’E-5 (CE-5) and Chang’E-4 (CE-4) missions, we measure the erosion depth and the total mass and combine the results with computational fluid dynamics (CFD) to extract the interparticle force. We then test the plume erosion model according to the results from image measurement and CFD and propose a new formula with which to calculate the threshold friction velocity at which plume erosion is initiated. This calculation shows that the interparticle force for a 4-μm-diameter particle is 3.38–16.1 nN. The results also show that the CE-5 landing plume stripped away a 1.2-cm-deep layer of regolith, creating a ≈10-m-diameter crater on the lunar surface, and dispersed ≈441 kg of lunar regolith. Any analysis of a CE-5 drilling sample that is sensitive to the regolith depth must consider this 1.2-cm-thick eroded layer. When a plume erodes the lunar surface, the minimum shear stress required is much less than that predicted by the erosion model, which can no longer be used to predict whether erosion will occur.

Engine plumes can seriously erode the Martian surface during the landing phase, causing a substantial alteration of the terrain of the immediate touchdown area and beyond. Furthermore, large amounts of lifted dust can block the view of boulders or craters, posing a serious threat to the lander's safety. Improving our understanding of the plume-surface interaction can reduce the risk of failure on a Mars landing mission. In situ studies on this subject are limited, particularly those relating to high-thrust single-nozzle engines. The Tianwen-1 represents the only Mars landing mission that employed such an engine with a thrust of -3000 N during the landing phase: Its success represents a unique opportunity in addressing this issue, providing an important reference for future Mars return missions. Here, we report the evolution characteristics of the plume-induced regolith erosion and the plume impingement effect measurements at the Tianwen-1 landing site. The results show that depressions and infilling are a complex process accompanying the changing of patterns as the lander descends. Specifically, the plume will seriously erode the area beneath the nozzle, causing the formation of a deep crater. Meanwhile, the expanding radial flow tends to flatten the peripheral area of the lander, which depends on the homogeneity of the regolith. To better quantify the impingement effects, some crucial parameters were extracted. The measured volume, diameter, and depth of the crater are 0.115 +/- 0.019 m3, 1.50 m, and -0.35 m, respectively. We also calculated the total erosion area and volume as 4879.4 +/- 297.7 m2 and 376.9 +/- 102.2 m3. In addition, plumeinduced infilling/erosion depths and rates during the landing phase were measured. Further, we investigated the shallow stratigraphic architecture exposed by the plume-induced crater beneath the lander, showing that it represents probably dust/sand-coated black rocks above at least -35 cm thick, bright reddish materials. These results provide valuable insights into the plume impingement effects on the Martian surface and the shallow subsurface layer at the Tianwen-1 landing site, which will benefit future Mars explorations.