Double Helix Rotating Tengs Driven by Ultra-Low Loading for Harvesting High-Entropy Water Flow Energy

Water flow energy in rivers and lakes is a huge clean energy source widely distributed in nature. Its low water velocity makes it difficult for electromagnetic generators to effectively harvest this energy. Therefore, harvesting high-entropy water flow energy is of great significance to the development of distributed power supply and sensing. In this study, we present a double helix rotating triboelectric nanogenerator (DHR-TENG) that can effectively convert the ultra-low water flow energy into electrical energy. The DHR-TENG is designed to optimize space utilization and has a reciprocating transmission mechanism to ensure the continuous operation, achieving a surprisingly high charge density of 356.69 μC⋅m−3 and peak power density of 11.66 W⋅m−3, and compared with similar structures reported by predecessors, the maximum elevation is about 242 times and 2 times, respectively. At ultra-low water flow velocity of 0.4~0.8 m/s, DHR-TENG has stable electrical output performance, and can drive self-powered temperature sensor systems and wireless signal transmission systems by harvesting water flow energy. This work not only effectively improves the electrical output performance at ultra-low water flow velocity, but also helps to promote environmental monitoring and provides a feasible method for establishing early warning in the environment.