Fabrication of a Wearable TENG Based on High-Stability Organic Hydrogel Electrodes

Triboelectric nanogenerators (TENGs) have been widely applied in sensors, wearable electronics, and human–computer interactions since their advent. However, conventional wearable TENGs still face two key challenges: limited stretchability caused by rigid metal electrodes and poor environmental stability. Here, we address both issues by replacing metal electrodes with a highly stable ionic organic hydrogel, enabling the development of two high-performance wearable TENG devices. The organic hydrogel is prepared via the method of “free radical polymerization + glycerol modification”, forming a polyacrylamide-sodium alginate double network structure. It possesses an ultrahigh elongation at break of 1046%, wide temperature stability from −25 to 80 °C (no freezing at low temperatures and a water retention rate of 87.2%), and excellent electrical conductivity of 0.604 S/m, breaking through the performance bottlenecks of traditional electrodes at the material level. Based on this electrode, two devices are developed: a Compression-Separation Mode Single-Electrode TENG (CS-TENG) and a Stretch-Release Mode TENG (SR-TENG). The CS-TENG, paired with an aramid nanofiber triboelectric layer, exhibits an outstanding power supply capability. It can charge a 10 μF capacitor to 5.65 V within 2 min, stably power an electronic watch for 9 s, or light 124 series connected LEDs, providing a reliable power source for wearable sensor systems. Relying on an integrated structure encapsulated by silicone rubber, the SR-TENG can not only independently distinguish stretching states through stretch release but also be paired with human skin. When mounted on fingers, arms, soles, and other body parts, it converts diverse human motions into readily distinguishable electrical signatures, enabling high-precision self-powered sensing. Overall, by combining hydrogel-electrode innovation with device-architecture optimization, this work realizes wearable TENGs that simultaneously offer high deformability, wide-temperature stability, and integrated energy-harvesting/sensing functionality, providing a viable pathway toward scalable, flexible, and wearable smart wearable systems.