Shaanxi University of Science & Technology

Self-powered flexible sensors exhibit revolutionary potential in next-generation wearable technologies owing to their exceptional sensitivity and self-sustaining energy harvesting capabilities. Nevertheless, their widespread deployment remains constrained by three fundamental challenges: dynamic mechanical mismatch between biological tissues and rigid devices, suboptimal energy conversion efficiency, and interfacial impedance fluctuation under deformation. Drawing inspiration from the unique negative Poisson’s ratio mesh architecture of lacewing wings, we present a bioinspired auxetic metastructure-engineered triboelectric nanogenerator. This innovative design integrates engineered collagen and micropatterned fluorinated ethylene propylene as triboelectric layers, unified by an auxetic framework with re-entrant hexagonal unit cells interconnected via triangular ligaments. The metastructure enables exceptional lateral expansion under longitudinal strain while simultaneously enhancing structural rigidity and deformation adaptability. This dual functionality effectively minimizes tissue–device mechanical mismatch, thereby significantly improving signal fidelity, sensitivity, and mechanical-to-electrical conversion efficiency during multi-axial deformations. The optimized device achieves remarkable performance metrics, delivering 478 V output voltage with 13.8% energy conversion efficiency in linear configuration, while demonstrating threefold enhanced stability (58 V, 7.58% efficiency) under complex bending compared to conventional designs. Integrated with a convolutional neural network-based machine learning enables exceptional classification accuracy (> 99%) across diverse material recognition tasks, validating its robustness as a next-generation platform for adaptive self-powered wearable sensing.

Fluorescence imaging is pivotal for elucidating biomolecular dynamics, yet the development of probes enabling specific and high-contrast imaging of multiple targets remains challenging. Herein, we designed and synthesized a novel cyanovinylene-based fluorogenic probe, CV-N₃, which synergistically integrates a dual-response mechanism combining excimer disaggregation with a viscosity-activated molecular rotor. The excimer formation and its CuAAC induced disaggregation are directly supported by dynamic light scattering and time-resolved fluorescence lifetime measurements. The probe enables specific covalent labeling of alkyne-tagged DNA and SNAP-tag proteins in living cells via copper-catalyzed azide-alkyne cycloaddition, with labeling specificity further confirmed by competitive binding assays. In solution, we validated the dual mechanism: covalent binding to targets triggers excimer disaggregation, causing a blueshift in emission from ∼630 nm to 535 nm, while the restricted local microenvironment of biomacromolecules activates the rotor character, significantly enhancing fluorescence intensity. Thus, CV-N₃ achieves high signal-to-background, wash-free imaging of both DNA and proteins in living cells, while exhibiting good photostability and low cytotoxicity. Its utility for dynamic cellular studies is further demonstrated by tracking cell turnover and multi-color imaging compatibility. This work establishes a versatile strategy for constructing multi-responsive probes, offering a promising platform for multiplexed biomolecular imaging and dynamic studies in complex biological systems.

Although conductive hydrogels have exhibited significant potential as flexible wearable sensors, they also face persistent challenges including mechanical strength, stability and poor performance in complex environments, particularly underwater. In this work, the poly(ionic liquid) based hydrogel (Ir-PR) with slide-ring structure was designed and synthesized via copolymerization of acrylic acid, fluorine-rich imidazolium ionic liquid ([VBIM]Br), N,N-diethylacrylamide (DEAA), and vinyl-functionalized polyrotaxane crosslinkers (PR-AC). The synergistic multiple non-covalent interactions and unique slide-ring based topological structure endow Ir-PR hydrogel with high mechanical performance (0.79 MPa tensile strength, 1168.82% elongation), remarkable toughness (4.023 MJ/m³ fracture energy), anti-swelling performance (19.6% volume increase after 30 days underwater), strong adhesion to diverse substrates, and stable linear gauge factors (GF) in a wide strain-sensing range. Ir-PR hydrogel could detect human motions and monitor electrocardiogram (ECG) signals for health monitoring. Notably, Ir-PR hydrogel exhibits superior capabilities in aquatic scenarios: stable detection of the robotic shark swimming modes (stationary, slow/fast swimming, turns) via resistance signals, underwater Morse code communication, and integration into a depth-sensitive alarm and positioning system for diver safety. This multifunctional hydrogel overcomes critical barriers for reliable operation in variable aquatic environments, opening new avenues for marine exploration and safety systems.