Scalable core-sheath braided yarn-based textile triboelectric nanogenerator for energy harvesting and human motion sensing

Wearable electronics require flexible and sustainable power sources, while conventional batteries suffer from limited lifespan, rigidity, and environmental concerns. Triboelectric nanogenerators (TENGs) offer a promising alternative by harvesting mechanical energy from human motion and enabling self-powered sensing through stimulus-induced electrical signals. To address the requirements of wearable applications, textile-based TENGs (T-TENGs) have emerged by integrating triboelectric functionality with flexible textile structures; however, conventional fabrication strategies involving chemical treatments, polymer coatings, or adhesive electrodes often compromise flexibility and durability. In this work, a high-performance T-TENG is developed using a flexible and scalable core-sheath braided yarn (CSBY), consisting of commercial multifilament nylon as the dielectric sheath and silver-plated nylon as the conductive core. This approach, which utilizes commercially available yarns without any additional coating or chemical post-treatment, enhances the mechanical robustness and electrical stability of the device. The optimized 2 × 2 Rib T-TENG exhibits superior performance, generating an output voltage and current of ~65 V and ~ 6.5 μA, respectively, under an applied force of 16 N at 8 Hz, with a maximum power density of 26 mW/m 2 at 7 MΩ. In addition, the T-TENG successfully charges capacitors and powers a series of 40 LEDs and is integrated into a wearable knee sleeve for self-powered motion monitoring. Combined with a custom-designed wireless readout system, the device enables detection of knee joint angles, cycling speeds, and daily activities such as walking and squatting. These results highlight the dual functionality of the CSBY-based T-TENG as an efficient mechanical energy harvester and versatile self-powered sensing platform, demonstrating its potential for next-generation wearable electronics and smart textile applications.