Natural Material-Based Multifunctional TENG Devices for Body Activity Monitoring and Sustainable Human–Machine Interaction

This work presents a comprehensive demonstration of multifunctional flexible triboelectric nanogenerator (TENG) devices for eco-friendly and sustainable wearable electronics. These flexible TENG devices were fabricated using polyimide as the tribo-negative layer and gelatin, a natural protein, as a biocompatible and ecofriendly tribo-positive layer, offering a scalable approach toward selfpowered electronics. Fabricated devices exhibited efficient conversion of biomechanical energy into electrical energy with a high opencircuit voltage of ~177 V and a short-circuit current of ~12.8 μA, surpassing the performance of various flexible natural materialbased TENG devices reported in literature. These devices delivered a maximum power density value of ~9.5 μW cm-2and enabled rapid charging of 10 μF and 22 μF capacitors, demonstrating the capability of these devices for realistic applications. The performance of these flexible TENG devices was further validated by evaluating stable output voltage over ~10000 seconds of continuous operation, highlighting their excellent durability. Multi-functionality, including body activity monitoring, an electronic keypad, and real-time robotic finger control for human–machine interaction, was successfully demonstrated. These demonstrations offer a promising route toward cost-effective, biocompatible, and high-performance TENG devices, paving the way for next-generation sustainable wearable electronic systems.