Fiber waveguide photoactuators (FWPAs) have shown great potential in space-relevant manipulation due to their electromagnetic interference immunity, compact and lightweight structure, and dexterous motion. Current FWPAs face severe limitations, including short manipulation distances, low light power programmability, low temperature shock tolerance, and limited articulation sites, resulting in low manipulation capacities in space applications. Herein, we first develop a high-performance FWPA that employs the bending loss characteristics of optical fibers for coupling internal light power with external thermal-sensitive materials. The FWPA features high optical coupling efficiency (absorptivity is ∼98.9%) and programmable light power supplies that enable a large bending angle of >200°, as well as exceptional kilometer-scale series polyarticular cascading manipulation along the optical fiber with low energy consumption (17 mW/°, 53 mW/mN), which fit the requirements of space-relevant manipulations. The proposed FWPA exhibits a high stability of deformation and force, as well as immunity to electromagnetic interference (performance variation <5.5%) and wide temperature shock (-196 to 175 °C). Nine fundamental designs of FWPAs and four distinct flexible FWPA cascading devices are developed by reconfiguring fiber arrangements and power distributions for different space applications, such as twisting, grasping, axial extension, and hinge actuation.

Wearable electronic devices should address the challenges of sustainable and stable power supply for long-time operation. The approach of combining radio frequency (RF) energy with solar energy is one of the solutions to address the issues of insufficient power supply or intermittency in single energy harvesting systems, while the matching of energy characteristics and power levels remains unresolved. This study aims to design a hybrid power system by integrating RF and solar energies to provide more reliable energy supply for wearable devices. Specifically, a novel externally slotted microstrip patch antenna operating at a targeted frequency of 2.5 GHz and an RF rectifier were designed to enable RF energy harvesting. Subsequently, a dynamic energy control method is proposed based on the power levels of different energy sources at various stages, which addresses the efficiency bottleneck in hybrid energy harvesting system. Subsequently, flexible solar cells, flexible RF rectifier, and flexible power management circuits are integrated into a flexible hybrid power system. Its performances were verified through simulations and experiments. The designed hybrid power system achieves a record power combining efficiency of 95.4%. Additionally, the system attains an areal power density of 3.92 μW mm-2, which represents an improvement of 65% as compared to existing systems. The proposed system also provides a new strategy to efficiently harvest multiple energies in dynamic environments.

Drag reduction is crucial for improving aerodynamic efficiency and enhancing energy conversion, such as wind turbines. Riblets inspired by shark skin are a promising approach in drag reduction technology. In this work, further inspired by the typical wind-eroded landform yardangs in nature, a novel passive metasurface of fluid mechanics, composed of low-high-low riblets (LHLRs), was proposed to achieve enhanced drag reduction performance. The aerodynamic drag reduction performance of LHLRs is validated by comparing them with skin-inspired riblets using a flow channel with an adjustable surface yaw angle. The surface turbulent flow characteristics are obtained via direct numerical simulation, then turbulence motion analysis explains the improved drag reduction performance of LHLRs. The results indicate that the drag reduction performance of the LHLRs is improved by 91.6 % compared to the shark skin-inspired riblets, and its robustness to wind yaw angles increases from 30 degrees to at least 45 degrees. Turbulence motion analysis reveals that LHLRs can weaken the transport of internal turbulence, further suppress turbulence penetration, and delay the formation of secondary vortices near the wall, thereby reducing dispersive stress and enhancing drag reduction performance. Moreover, the equivalent turbulence-free region between the primary and secondary riblets of LHLRs optimizes the near-wall turbulence distribution, leading to a modification of the optimal non-dimensional square root of the groove cross-section l+g in the riblets drag-change curve.

Solid-state spin defects encode local perturbations as measurable shifts in spin-transition frequencies, but mechanical actuation and quantum readout remain physically separated, resulting in a discrete measurement setup. Integrating these functions requires an on-site mechano-quantum interface that programs the lattice state of a defect host and quantitatively maps it onto the spin Hamiltonian. Here we first report an on-chip programmable mechano-quantum transducer (OCPMQT) that integrates voltage-defined micromechanical actuation with in situ spin-frequency readout in a two-dimensional van der Waals quantum-defect host. Mechanically programmed lattice states are encoded as shifts in the axial zero-field splitting parameter and resolved by optically detected magnetic resonance (ODMR) spectroscopy. Within a chip volume of 2.05*10^-2 cm^3, the transducer accesses ODMR-inferred strains as low as 0.0080

Accurate measurement of three-dimensional micro-aerodynamic forces is essential for the development of aerospace, micro air vehicles, robotics, and bio-inspired engineering. However, as the measured forces decrease, significant crosstalk interference and coupling between force components become evident. Due to limitations in measurement and installation methods, improving measurement resolution and precision of existing multi-axis sensors remains challenging. This paper presents a novel wind tunnel balance based on the air-floating principle. The balance achieves decoupling-free measurement of three orthogonal micro force components, with significantly suppressed inter-axis coupling. A self-designed calibration apparatus was used to calibrate the balance, demonstrating horizontal in-plane resolutions of approximately 1.28x10-5 N (z-axis) and 1.17x10-5 N (x-axis), and a normal-direction (y-axis) resolution of approximately 8.72 x 10-5 N. When measuring force of 1.0 x 10-3 N, the measurement precision was no greater than 0.12%. The balance's performance was validated by measuring forces on a single pigeon secondary feather at low wind speeds (1 5 m s-1) and various angles of attack (-20 degrees 20 degrees). The results show that the balance had accurately measured the component variations of force at O (10-4) O (10-2) N, revealing how the flexible vane curvature affects lift, drag, and spanwise forces. By eliminating complex decoupling processes, the proposed balance enables more precise and efficient micro-force measurements in multiple dimensions, offering significant advantages in micro-aerodynamics and demonstrating considerable value of the research on novel micro air vehicles.

Precise monitoring in extreme aerodynamic environments requires sensing materials with high thermal endurance. However, the application of traditional metal oxide sensing films is often limited by coupled microstructural and chemical degradation driven by thermodynamic and kinetic instabilities. In this work, alumina-reinforced indium tin oxide (ITO-Al2O3) composite films are developed via standard Micro-Electromechanical Systems (MEMS) processes. The modified films exhibit improved electrical stability and piezoresistive performance at elevated temperatures up to 900 degrees C, with a reduced resistance drift rate of 0.001%/h. Microstructural characterization indicates that this enhancement is associated with the formation of a core-shell structure, which mitigates detrimental degradation pathways like grain growth, defect evolution, and elemental diffusion in pristine ITO films, thereby improving their structural, chemical, and electrical stability at elevated temperatures. These results demonstrate the feasibility of tailoring thermally stable sensing films via composite engineering, providing a promising approach for the development of robust sensing devices for next-generation aerospace and energy applications.

Conventional rigid human‐machine interfaces (HMIs) face significant limitations, including mechanical mismatch with human skin and dependence on batteries requiring frequent replacement/recharging, hindering seamless and biocompatible interactions. Self‐powered hydrogel sensors, characterized by properties such as energy autonomy, tunable mechanics, tissue‐like softness, and biocompatibility, have emerged as promising candidates for advancing wearable healthcare, soft robotics, and next‐generation HMIs. However, challenges encompassing long‐term cycle stability, complete energy autonomy, and adaptive smartness need to be addressed for their further development. Therefore, a systematic understanding of the development and current challenges of self‐powered hydrogel sensors as HMIs is of great importance for realizing their full potential in flexible and intelligent interaction paradigms. This paper reviews the development of self‐powered hydrogel HMIs, focusing on performance‐optimizing strategies for diverse requirements, categorization by energy generation mechanisms, key applications with emphasis on artificial intelligence (AI)‐enabled smartness, and their limitations. Finally, the challenges and future opportunities associated with self‐powered hydrogel HMIs are discussed. This review is believed to provide guidelines for advancing next‐generation HMIs that bridge energy autonomy, multimodal sensing, and AI‐enhanced responsiveness, with hydrogel sensors serving as a cornerstone.

The measurement of wall shear stress using MEMS hot-film sensors has received considerable attentions. However, the substrate heat losses and axial diffusion effects fundamentally constrain the sensitivity and spatial resolution of MEMS hot-film sensors. In this work, a novel trapezoidal sandwiched dual-layer hot-film sensor with both reduced substrate and axial diffusion effects is proposed and micro-fabricated. This paper aims to verify and clarify the improvements in steady-state response and the space-resolved capacity of hot-film sensors using the proposed dual-layer active thermal insulation strategy. Both static calibration experiments and numerical simulations were conducted to achieve this. The trapezoidal sandwiched dual-layer sensor shows over 100 % improvement in output voltage sensitivity compared to its single-layer counterpart within a wall shear stress range from 0 to 5 Pa. We emphasize and clarify that the widely used sensitivity metric based on total heating power is inadequate for dual-layer hot-films. Instead, a more preferable metric relating to the relative net heating power, reveals that the newly proposed sensor exhibits 11 times the sensitivity of its single-layer counterpart and 6 times that of the previously reported dual-layer sensors. Besides, the effective sensing length of the trapezoidal sandwiched dual-layer sensors is no more than twice its physical size. Meanwhile, axial diffusion is greatly reduced, based on which the well-known conflicting constraint between spatial resolution and edge effects of conventional hot-films could be loosened. The confirmed reductions in substrate and axial diffusion open new opportunities for high-quality wall shear stress measurement using thermal sensors in the future.

Drag reduction and anti-icing are critical challenges in aircraft operations. Traditional anti-icing films are often inefficient. To meet the complex environmental demands of modern aviation, a dual-functional film combining drag reduction and anti-icing properties was developed. Using laser direct writing lithography, micro-riblet structures were fabricated on flexible PET films, which were then combined with a nanoparticle coating to create a superhydrophobic surface, achieving long-lasting drag reduction and anti-icing performance. The film exhibits a water contact angle of 156 degrees, delays ice formation by up to 201 s, and reduces ice adhesion strength to 49.8 kPa. Wind tunnel tests show a maximum drag reduction rate of 6.6 % under high Reynolds numbers. The film also demonstrates excellent mechanical durability, chemical stability, and self-cleaning performance. This integrated solution enhances resource efficiency and provides a novel approach for aviation technology optimization.

Complementary metal-oxide-semiconductor (CMOS)-compatible energy storage batteries with distributed on-chip power supply capability are essential for the development of advanced system-on-chips (SoCs). However, such devices have not been reported till now. The current concentrated power architecture of SoCs based on a discrete battery, with redundant encapsulation materials and tabs, exhibits low energy storage density, energy utilization efficiency, and integration capability. Herein, CMOS-compatible lithium-ion batteries (CLIBs) are developed for distributed on-chip power supply in SoCs. The anode and cathode are prepared on two different wafers, which are bonded with electrolytes and separators to form the CLIBs. The CLIBs exhibit an areal capacity of 3.54 mAh cm-2 and energy density of 34.375 mWh cm-3 at 0.1C and simplify the integration of a multi-sensor SoC with through-silicon vias and redistribution layer circuits. Further, the dual-CLIB distributed power architecture exhibits nearly doubled energy utilization efficiency as compared to the centralized power architecture.

Reported giant piezoresistive effect of silicon nanowires (SiNWs) motivates research of SiNWs-based devices, particularly for inertial and force sensors, whose fabrication however remains a challenge. This paper reports a controllable manufacturing process to fabricate a force sensor utilizing $<600 ~\text{nm} \times 600 ~\text{nm}$ SiNWs with a GF of 35 as the sensing element while $10 \mu \mathrm{m}$ thick comb fingers as the actuator and force generator. Different from the previous bottom-up process using epitaxial growth, this work proposes a straightforward top-down process with stepwise controllable etching and only ultraviolet lithography to integrate SiNWs of which minimum diameter is 100nm with the $10 \mu \mathrm{m}$ thick actuator. A fabricated force sensor demonstrates a sensitivity of $508 \text{ppm} / \mu \mathrm{N}$ and linearity of $\pm 1.4 \%$.

Dandelion seed-inspired low-Reynolds-number flyers represent a potential solution for exploring the extremely thin atmosphere of Mars. However, the flight dynamics of their natural prototype, the dandelion seed, remain incompletely understood. This paper establishes a flight dynamics model for the dandelion seed. Using the Runge-Kutta method to numerically integrate the model, the dynamic stability of bio-inspired micro-flyers with different beak lengths is investigated in ascending shear flows under various combinations of shear-rate amplitude and oscillation frequency. The results show that varying the beak length significantly affects the flyer’s moment of inertia. In most cases, the short-beaked flyer exhibits better stability, whereas a longer beak helps stabilize the flyer’s attitude under low shear intensity and high oscillation frequency. An increase in shear intensity induces chaotic motion in the long-beak flyer. In chaotic regimes, the vertical velocity distribution of the long-beaked flyer exhibits distinct symmetry breaking, enabling it to extract energy from the oscillatory flow, accumulate velocity, and thereby increase flight altitude and flight efficiency. Finally, a preliminary configuration of a dandelion seed-inspired Martian micro-flyer featuring a variable pappus structure and an adjustable beak length is proposed. Analogous to dandelion seeds exploiting thermal updrafts, the flyer is designed to achieve sustained flight by leveraging updrafts induced by thermal gradients near the Martian terminator. The findings provide new insights into the design of bio-inspired micro-flyers and into the dispersal mechanisms of Asteraceae seeds.

Spectral-polarization imaging (SPI), which captures spatial, spectral, and polarization information simultaneously, has broad applications in biomedical diagnostics, remote sensing, and deep space exploration due to its ability to reveal intrinsic material properties. However, different application scenarios often impose diverse and sometimes conflicting requirements on imaging speed, spatial-spectral resolution, and polarization states, limiting the adaptability of conventional single-mode systems. In this work, we propose a DMD-based multimodal spectral and spectral-polarimetric imaging system within a unified measurement framework. By organizing staring, scanning, and transformed spectral imaging into a consistent column-wise modulation scheme, the system supports flexible mode selection within a unified architecture. The framework also naturally extends to spectral-polarimetric imaging without modifying the underlying acquisition principle. A key feature of the proposed approach is the introduction of controllable parameters that enable adaptive resolution tuning. In particular, the column group size m0 governs the trade-off between temporal-spatial-spectral resolution. Experimental results on representative spectral and spectral-polarimetric scenes demonstrate that the proposed system enables controllable trade-offs among spatial resolution, spectral resolution, and temporal resolution within a single platform.

Shape-morphing mechanisms help organisms adapt to their environment and have inspired applications in advanced systems. Designing microrobots that are both miniaturized and capable of fast shape changes is challenging, as performance can be weakened at small scales. Ultrasound offers advantages such as fast response, repeatability, and programmability, making it suitable for enabling shape-morphing microrobots. Here, we introduce an acoustic micromachine composed of two microbubbles connected by a microhinge. Acoustic-field excitation generates interaction forces between the bubbles, enabling complete micromachine deformation within milliseconds. We also present design principles for programmable acoustic deformation, enabling both forward and inverse design, precise control, and information storage. By tuning the excitation amplitude, the micromachine can switch between multiple modes. As proof of concept, microlotus and microbird structures are demonstrated with controllable and stable performance. Balancing structural miniaturization with reliable shape-morphing performance is challenging in microrobot design. Here, the authors design an acoustic shape-morphing micromachine that can rapidly switch between multiple modes with precise control.

Skin friction, or wall shear stress is a fundamental parameter for characterizing turbulent boundary layer (TBL). Among various methods, the floating element (FE) method has long been advocated and developed. However, accurately measuring WSS for small-area samples remains challenging. This paper proposes air-bearing-based high-resolution micro skin-friction balance and a corresponding sliding-covering measurement method. As an extension of the traditional flush-mounted FE measurement method, it reduces errors caused by the edge gap and gap flow of the floating elements, and employs a clamping mechanism for high-precision assembly, thereby enhancing the measurement efficiency and accuracy for small-area samples. The error sources in balance calibration and measurement were carefully analyzed, with corresponding uncertainty calculated. The measurement range and resolution are +/- 0.12 Nand 2.5x10-7N, respectively. Fora smooth surface, assume the measured force is 1x10-4 N, and the measurement precision is approximately 0.047%. The balance is validated using a smooth-wall zero-pressure-gradient TBL. The measured skin-friction coefficient, equivalent to /infinity, generally follows a Coles-Fernholz relation = 2 [1/ ln (Re) + ]-2 within 3% (with chosen constant of = 0.384 and = 4.12) fora momentum-thickness-based Reynolds number Re = 1050 similar to 3361. Additionally, the skin friction on the surfaces of two envelope materials (EMs) used for airships was measured using the sliding-covering method. The results were compared with those of a smooth surface, revealing that the outer surfaces of EMs exhibited a drag reduction effect at low Reynolds numbers, with further potential for improvement in a broader range of Reynolds numbers. The balance measured the skin-friction differences between samples and revealed that the roughness of the samples affected the precision of the measurements. Asa direct measurement method, the results have higher reliability.

Through-silicon via (TSV) technology realizes high-density interconnections within and between different dies (chips) by vertically drilling holes in silicon and filling them with various conductive materials. It is an effective way to achieve miniaturization, lightweight, and multi-functionality in post-Moore microelectronics. In this review, the process optimization in TSV preparation, various filling techniques, and different filler materials are comprehensively summarized and discussed. It also delves into the characterization and reliability analysis of TSV performance under multi-physical fields of mechanical, thermal, and electrical. Moreover, the review explores the challenges and solutions for TSVs in regards of integration/packaging and cost aspects. This review can be used to understand the latest research progresses and applications of TSVs, and provide reference and guidance for future research and applications for advanced TSV technology.

Many outdoor devices require effective snow prevention solutions, yet existing passive anti-icing technologies are inadequate for snow repellency due to the variability of snow properties. This study addresses this gap by proposing a bioinspired micro-grooved anti-snow structure that minimizes van der Waals forces through reduced contact area and mitigates capillary effects via a V-shaped design, facilitating the separation of liquid water at the interface. Snow-shedding performance is shown to be highly sensitive to surface roughness, with the periodic smoothness of micro-grooves significantly reducing mechanical interlocking with snow. In contrast, hierarchical superhydrophobic structures strongly interlock with ice grains, preventing spontaneous snow-shedding even at extremely low adhesion forces. By embedding superhydrophobic nanoparticles into the micro-groove structure, this study presents a multifunctional design that integrates anti-icing, anti-snow, and water-repellent properties. Experimental results demonstrate that the structure effectively balances adhesion reduction and snow-shedding performance, showing promising potential for photovoltaic solar power systems and large-scale architectural applications.

This article presents an integrated flexible ice-sensing sensor array system based on microwave resonance. The system combines ice detection with electric heating de-icing, establishing a 3-D electromagnetic model for the microwave resonator. A novel interdigital circular complementary split-ring resonator (ICCSRR) structure [evolved from complementary split-ring resonator (CSRR)] enables high-precision ice thickness detection (0-8 mm, +/- 0.1-mm resolution, and <300-ms response). Innovatively, the resonant microstrip integrates with a flexible heating film to form a self-sensing-self-heating composite unit, using impedance phase characteristics for real-time de-icing feedback and dynamic power adjustment (6-10 W). Its fully flexible design suits drone icing areas, while array-based detection provides multipoint ice shape data. Verified via an ice simulation-S21 testing platform, the system distinguishes 0.1-mm ice at-21 degrees C, removes 4-mm ice within 10 s at-20 degrees C in high-power mode, and prevents icing via low-power pre-activation. Sensors offer synchronous de-icing progress feedback, demonstrating excellent ice-sensing and de-icing performance.

The dynamic behavior of droplets on superhydrophobic microstructured surfaces plays a crucial role in applications such as self-cleaning, thermal management, and anti-icing. While previous studies have extensively investigated droplet impact dynamics, the effect of the droplet-to-microstructure size ratio (D/S) on rebound behavior remains insufficiently understood. This study systematically examines the influence of D/S on impact dynamics, revealing a transition from inertia-dominated macroscopic effects to adhesion-governed localized interactions. At larger D/S, inertia and surface tension primarily dictate retraction, leading to symmetric rebound. However, as D/S decreases, intensified contact line pinning prolongs contact time and suppresses rebound, fundamentally altering retraction dynamics. A previously unreported transition in droplet retraction identified, where localized constraints progressively hinder contact line motion, shifting the governing mechanism from inertia-driven to adhesion-controlled behavior. To further elucidate this transition, a theoretical framework is established to characterize the role of D/S in contact line dynamics, linking size-dependent interfacial interactions to droplet mobility. These findings provide new insights into droplet impact physics and serve as a theoretical foundation for optimizing superhydrophobic surfaces in applications such as anti-icing and spray cooling.

Droplet impact behavior on superhydrophobic surfaces plays a crucial role in various thermal management applications, particularly in anti-icing, condensation heat transfer, and moisture control. While extensive studies have focused on freezing-induced adhesion, rebound failure can also occur under non-freezing conditions, where conventional explanations are insufficient. In this study, we systematically conducted droplet impact experiments on cold superhydrophobic surfaces under controlled temperature difference (Delta T) conditions between the droplet and the surface. The results demonstrate that rebound behavior is primarily governed by Delta T rather than the individual temperatures of the droplet and surface. When Delta T exceeds a critical threshold of 15 degrees C, droplet rebound begins to fail due to intensified interfacial condensation, which forms liquid bridges inside surface microstructures and significantly increases energy dissipation. This temperature-difference-driven interfacial condensation mechanism provides new insights into dynamic wetting failure under thermal gradients, and suggests potential strategies for improving surface design in condensation management, anti-icing, and coldenvironment heat exchange systems.