Environmentally Friendly Hydrogel-Based Triboelectric Nanogenerators for Versatile Energy Harvesting and Self-Powered Sensors

Triboelectric nanogenerators (TENGs), as a promising energy harvesting technology, have been rapidly developed in recent years. However, the research based on fully flexible and environmentally friendly TENGs is still limited. Herein, for the first time, a hydrogel-based triboelectric nanogenerator (Hydrogel-TENG) with high flexibility, recyclability, and environmental friendliness simultaneously has been demonstrated. The standard Hydrogel-TENG can generate a maximum output power of 2 mW at a load resistance of 10 MΩ. The tube-shaped Hydrogel-TENG can harvest mechanical energy from various human motions, including bending, twisting, and stretching. Furthermore, the system can serve as self-powered sensors to detect the human motions. Additionally, the utilized Polyvinyl Alcohol hydrogel employed in this study is recyclable to benefit for fabricating the renewable TENG. The open-circuit voltage of renewed hydrogel-TENG can reach up to 92% of the pristine output voltage. This research will pave a potential approach for the development of flexible energy sources and self-powered motion sensors in environmentally friendly way.