Bridging biological and artificial systems, intelligent interfaces drive the demand for flexible electronics that emulate the skin's multifunctionality. However, achieving such multifunctionality in a compact, self-sustained form remains challenging, as multimodal sensors often rely on rigid materials, discrete components, and external power sources. Herein, this study presents a single-component poly(vinyl alcohol) hydrogel e-skin integrating thermogalvanic, piezoionic, and diffusion mechanisms for self-powered sensing of skin temperature, arterial pulsation, and sweat secretion, simultaneously. The hydrogel features high stretchability, low modulus, and a prismatic architecture synergizing ionic polarization. Moreover, a temporal machine learning model with local attention is developed to decouple multimodal signals. Of practical importance, an active multimodal signal generator wristband is developed as a multifunctional human-machine interface for physiological detection, robotic control, and haptic feedback reproduction. Hence, this hydrogel e-skin represents an efficient material platform for intelligent interactions, showing broad potential for real-time health monitoring, robotic control, and virtual reality.

ABSTRACT Stretchable conductive structures are essential components to provide compliance with deformation in flexible electronics. They are conventionally designed using empirical methods that adopt serpentine, meander, or fractal shapes, which enable quick prototyping but have limitations in mechanical and electrical performance under strict layout and boundary constraints. In µLED testing, topology optimization (TO) is a target‐oriented design approach that determines the optimal material distribution within the design domain and can better adapt to boundary conditions and objectives. Here, we propose a TO method for designing stretchable conductive structures. TO generates a structure with at least 15% stretchability in an 80 µm square area, meeting additional design constraints. The topology‐optimized structure exhibits an internal average stress of 134.32 MPa at 30% deformation and maintains fatigue performance for more than 5000 cycles, significantly outperforming empirically designed counterparts. These results demonstrate the great potential of TO to assist or replace empirical design in flexible electronics. filling a vital technical gap in high‐density and 3D terrain compatibility is simultaneously limited.

In flexible wearable electronics, the mechanical demands on substrate materials such as polyimine (PI) membranes vary significantly with the application. Adding toughening fillers to adjust the mechanical properties is effective. However, such approaches typically enable only unidirectional enhancement, lacking the capacity for controllable, bidirectional regulation. Inspired by mixed matrix membrane design, this work introduces iCONs into ionic polyimine network (IPIN). By modulating hydrogen bond cross-linking density and molecular chain entanglement through iCONs loading, the mechanical behavior of the composite membranes can be tuned from flexible (76.10% elongation at break) to rigid (8.56 MPa tensile strength). Notably, the IPIN-TpPaSO3-30% based flexible wearable sensor shows rapid, accurate, and stable electrochemical response to volatile iodine, promising for real-time detection. This work demostrates iCONs' potential in controllably regulating the mechanical properties of membrane materials, offering a novel approach for creating flexible membranes tailored to different applications.

ABSTRACT The nylon liners of multilayer composite pipelines used in subsea mineral resource transportation are prone to internal wear and thinning caused by abrasive slurry flow, posing serious safety and reliability concerns. To enable the efficient and cost-effective, non-destructive evaluation of such nonconductive liners, this study investigates the applicability of coplanar capacitive sensing (CCS) technology for defect detection and develops an optimised flexible CCS array for internal pipe inspection. Numerical simulations were conducted to analyse the influence of an underlying conductive layer on the fringing electric field and the resulting detection sensitivity. The results reveal that the conductive layer compresses the electric field, leading to reduced sensitivity and the emergence of a negative sensitivity region with increasing defect depth. The parametric optimisation of electrode geometry demonstrates that longer and wider detecting electrodes, together with smaller detecting electrode space, significantly enhance detectability. A flexible CCS array fabricated using flexible printed circuit board technology was constructed and experimentally validated. The results confirm that capacitance variation exhibits a nonlinear relationship with defect depth and inflection behaviour in the presence of a conductive layer. The proposed CCS array successfully detected defects on the nylon liner, demonstrating its feasibility for internal inspection applications.

Conductive hydrogels, combining flexibility and electrical conductivity, show great potential in flexible electronics, wearable sensors, and smart materials. However, their practical applications remain constrained by insufficient mechanical strength, unstable sensing performance, and low structural integration. To address these challenges, we develop a highly sensitive MXene@PDA/PF127-DA/Zn2+ conductive hydrogel, which achieves an effective balance between mechanical strength and sensing performance through the synergistic effect of multiple components. MXene nanosheets serve as the primary conductive framework, while the polydopamine coating effectively enhances its dispersibility and interfacial adhesion. In addition, the double-bond modified PF127-DA can self-assemble into micelles, providing a dynamic structure that offers better elastic properties for the conductive hydrogel. Finally, the introduction of Zn2+ as a dynamic coordination crosslinker further enhances mechanical toughness. This collaborative design makes it possible to construct a new type of conductive hydrogel system with high mechanical strength, excellent stability, and tunable sensing performance. When attached to human skin, the conductive hydrogel can quickly respond (response time up to 0.089 s) and accurately detect subtle electrical signals associated with joint motion and muscle contraction. Furthermore, real-time signal acquisition and wireless transmission are achieved through an integrated electrochemical workstation and Bluetooth module, enabling efficient motion monitoring. This study provides a promising strategy for designing multifunctional conductive hydrogels for next-generation wearable bioelectronic devices.

ABSTRACT Organic field‐effect transistors (OFETs) are indispensable integral parts of the future wearable electronics such as artificial e‐skins, flexible displays, health monitors, and other areas. The power consumption is one of the important issues needed to be addressed for the commercialized of OFETs. Therefore, developing the low‐voltage operation OFETs is urgently needed. The gate is an important functional layer in OFETs, which isolate the charged transport layer and gate electrode, regulate electronic performance, and directly affect the power consumption. In this review, we firstly introduced the basic structures of the OFETs, and the roles of the gate dielectrics in OFETs. Next, we summarized the recent progress in polymer gate dielectrics for low‐voltage OFETs including high‐ k polymers, polymer electrolytes, polymer‐based hybrids, with emphasis on leakage current and operating voltage in the devices. Lastly, challenges and outline future research perspectives of polymer gate dielectrics for future low‐voltage flexible electronics are discussed in conclusion and outlooks.

Abstract The peripheral tissues consist of skin and subcutaneous tissue. Their multilayered biomechanical properties serve as key health indicators, and are crucial for clinical applications. Flexible electronics offer a promising approach for continuous in vivo monitoring of peripheral tissue biomechanics. However, these methods depend on complex dispersion analysis or extensive experimental data fitting, which limit their practicality. This study develops an analytical model based on an eccentric rotating mass (ERM) motor for direct and simultaneous measurement of the elastic moduli and thickness of the top skin layer of bilayer tissue. The analytical model used to evaluate tissue compliance involves three dimensionless parameters: the modulus ratio between the top and bottom layers, the normalized thickness of the top skin layer, and one parameter related to ERM. Both simulations and experiments confirm the model's accuracy, showing average errors of only 10% in the inverse characterization of bilayer moduli and thickness for representative bilayer tissue phantoms, paving the way for the development of flexible devices for in vivo tissue health monitoring.

Hydrovoltaic technologies face challenges of low conversion efficiency and narrow operational temperature ranges, limiting their practical applications in extreme environments. Here, we propose a molecular clustering strategy that leverages organic molecules to interact with organic salt anions, forming stable composite clusters. These clusters enhance water's phase change energy barrier and thermal stability while mitigating electrostatic shielding effects, effectively overcoming ion transport bottlenecks across a wide temperature range. The hydrogel achieves an operational temperature range from -35 °C to 80 °C and increases power density by an order of magnitude compared to existing technologies. Furthermore, the hydrogel demonstrates exceptional thermal and mechanical stability, maintaining stretchability above 1000% and stable performance under harsh conditions such as freezing and high heat. These advancements enable hydrovoltaic systems to operate reliably in flexible electronics, environmental monitoring, and self-powered devices across extreme environments, providing sustainable energy solutions for diverse and demanding scenarios.

Current crystalline thin-film production techniques typically require specific growth substrates, posing significant challenges for their use in flexible electronics and integrated optoelectronics. In response to these challenges, we introduce a novel method called ‘induced fit growth’, inspired by the induced fit theory in molecular biology. This method overcomes the limitations of current techniques by enabling the deposition of Ga-based semiconductor films, including GaSb, GaSe, GaAs, and GaAsSb, with controllable thickness and morphology on arbitrary substrates. Utilizing a low-cost, wafer-scale vapor deposition process compatible with standard semiconductor procedures, these Ga-based films can be patterned for various functional applications. For example, the patterned Ga-based thin films exhibit broad applicability in p-channel transistor arrays (with hole mobility of 0.25 cm2 V⁻1 s⁻1), functional synaptic devices, and flexible omnidirectional imaging sensors (maintaining functionality at incident angles as low as 5°). Overall, the proposed induced fit growth method facilitates the growth of Ga-based semiconductor films with greater integration flexibility, enhancing their advanced functionality and broad applicability.

Reconfigurable field-effect transistors (RFETs), which allow postfabrication switching of device polarity, are promising candidates for compact and functionally flexible circuit design. Here, we demonstrate large-scale dual n-/p-channel RFETs based on homogeneous monolayer WSe2, integrated with a charge-trapping layer. Ambipolar transport is achieved by forming parallel n- and p-type conduction paths through selective doping. In addition, a multilayer gate dielectric stack (hBN/HfO2/Al2O3) enables complete nonvolatile switching between n- and p-type modes via charge-trapping. Exploiting this reconfigurability, we realize ternary content-addressable memory using only two RFETs (2T) per cell, where polarity combinations encode the three logic states ('0', '1', and 'X'). Furthermore, a full set of Boolean logic gates─including AND, OR, NAND, and NOR, is demonstrated using series and parallel 2T configurations. These results establish dual n-/p-channel WSe2 RFETs as scalable and functionally versatile building blocks for programmable logic and memory in future computing architectures.

The rapid progress of flexible electronics demands materials that simultaneously offer outstanding electrical and optoelectronic performance with mechanical durability. Bismuth oxyselenide (Bi2O2Se) has emerged as a promising candidate due to its high carrier mobility and excellent optoelectronic properties. However, realizing large-area, high-quality Bi2O2Se nanosheets suitable for device fabrication remains a challenge, as conventional low-pressure chemical vapor deposition (LPCVD) offers limited scalability and narrow growth conditions. This study presents the synthesis of millimeter-scale Bi2O2Se nanosheets using atmospheric pressure chemical vapor deposition (APCVD), achieving domain sizes up to 0.4 mm. Systematic investigation of the growth parameters and mechanisms accompanied by COMSOL simulations to study the adatom diffusion on the substrate surface reveals the key factors that enable such large-domain formation. The resulting nanosheets exhibit excellent electronic transport properties, with average carrier mobilities of 110 cm2V-1s-1 at room temperature and more than 3700 cm2V-1s-1 at 2.3 K. Devices fabricated on flexible substrates maintain stable performance under repeated mechanical bending, underscoring their robustness and durability. These results establish APCVD-grown Bi2O2Se as a scalable platform for next-generation flexible electronic and optoelectronictechnologies.

A transistor with fully laminated plate-type triode electrodes, source, drain and gate offers higher current density than a typical transistor design by allowing a 2D current path. Nanoscale transistors face challenges like off-state leakage, so we introduce a new design using a laminated plate-type architecture and a dual-modulation strategy to improve performance and stability. Both top and bottom gates are used as active electrodes to fully control the channel's thickness. A micro-hole patterned electrode is employed to enable effective gate field penetration into the channel, while a graphene electrode facilitates Fermi-level modulation and improves field transfer. Furthermore, a leakage blocking layer is inserted to suppress unwanted carrier injection in the source and drain overlap regions. The device achieves low off-state current of ≈10-12 A and an on/off-current ratio exceeding 106 at VDS of 3V. It also delivers high output currents under low-voltage operation (1mA cm-2 at 0.1V and 50mA cm-2 at 1V). Despite a nanoscale channel length, the device maintains near-zero VTH. The fully encapsulated channel shows strong reliability against bias stress and light. This work shows that a laminated vertical design with dual-gate control effectively enhances the stability of nanoscale transistors, highlighting their potential for next-generation low-power logic, memory, and flexible electronics.

Cardiovascular disease (CVD), the leading global cause of death, highlights the critical need for effective blood pressure management. Non-invasive blood pressure (NIBP) monitoring, compared with invasive methods, enables home-based and long-term use, supporting early detection and continuous care. Despite significant progress, challenges remain, including accuracy issues, insufficient validation in real-world settings, limited application-specific sensor designs, and inadequate calibration standards and validation platforms. These gaps call for a systematic review to clarify the unmet needs and future research directions. This article reviews current advances in four key areas: (1) novel NIBP estimation principles designed to minimize user intervention; (2) flexible and wearable electronics that improve accuracy and comfort; (3) integration with theranostic applications and broader healthcare scenarios enabled by NIBP technologies; (4) calibration and validation strategies that enhance reliability and accuracy. With the rapid growth of home healthcare and AI-enabled wearable systems, addressing these challenges is essential to advance personalized, precise and stable cardiovascular medicine.

Humidity regulation plays a critical role in precision electronics, advanced storage, thermal, and energy management applications. While real-time monitoring of water molecule dynamics during moisture sorption and desorption processes could provide crucial hygroscopic parameters for smart humidity regulation, conventional gravimetric methods suffer from low tracking speed, limited accuracy, and an inability to perform in situ detection. Here, we report a flexible hygroscopic electronics (FHE) capable of simultaneously regulating environmental moisture and dynamically monitoring sorption-desorption processes through water-mediated resistive changes in confined space. The targeted electronics exhibit exceptional performance, including a fast hygroscopic response of ∼2.1 s at 90% RH, cycling stability, and stable sorption-desorption properties over more than 50 cycles. By engineering a series of modular array-based sensors, we achieve adjustable humidity control in enclosed spaces according to application-specific requirements. As a proof-of-concept, the intelligent electronic array successfully maintains stable humidity conditions even in damaged equipment enclosures (>3.5h) and provides rapid sensory alerts. This work establishes an intelligent core-shell FHE system, that absorbs unexpected moisture through a bio-based hygroscopic core and simultaneously monitors the water sorption/desorption behaviors by a thin conductive shell, which allows remote warning for potential seal risk of equipment in an early stage.

With the advancement of flexible electronics and low-power circuit design, wearable sensing systems have emerged as a interdisciplinary research area within electronic and computer engineering. These kind of systems can support continual identification with non-disruptive, precise sensing of the physical signs of person with pliable, various type sensor arrays. Viewed from the perspective of the systems engineering approach, this paper classifies wearable device architectures into three mutually supportive electrical paths: the analog signal chain, the digital signal chain, and the energy self-sufficiency chain. At the signal chain level, it focuses on analog front-end design for flexible electrochemical, strain sensor, high-input-impedance Transimpedance Amplification design, differential anti-interference design, analog-to-digital conversion design to ensure that the signal-to-noise ratio and low-drift performance of the microampere-level signal are very high. In the digital chain the study is on the signal processing and information transmitting using an embedded MCU unit. Adaptive filtering, dynamic gain adjustment, and event-driven communication have achieved real-time, low-power data management: The energy chain combines biofuel cell (BFC) and power management unit (PMU), it's proposing the hybrid power chain, which would be combining NFC and the energy scheduling algorithm for autonomous power. Looking at it from the system level, it is hard to say that wearable electronics' core competitiveness comes from better analog, digital, but more likely the synergy between them: This provides a solution for field-effect transistors (FETs) and self-powered smart health trackers. It establishes a scalable implementation approach suitable for both low-power signal processing and energy-autonomous circuits.

Flexible light-addressable electrochemical sensor using one-step synthesized PTEB organic semiconductors.

From colloidal nanoparticles in non-polar solvents to 3D microstructures: a new paradigm in Convective Self-Assembly.

Dynamic oxygen sensing technology: progress from large-scale equipment to portable monitoring.

Wireless, battery-free self-detecting smart arteriovenous graft for stenosis diagnosis in dialysis patients.

Decoupled and high-sensitivity strain-temperature bimodal sensors based on chitosan-enhanced hydrogel with local strain concentration.