A Non-Encapsulated Polymorphous U-Shaped Triboelectric Nanogenerator for Multiform Hydropower Harvesting

Various structures for triboelectric nanogenerators (TENGs) have been designed to generate clean, low-frequency hydropower, and provide solutions for next-generation sustainable power supplies, including the solid-liquid contact electrification mode and full-packaged solid-solid contact electrification mode. However, most of them can only adapt to a single form of hydropower. Moreover, electrostatic shielding in water and corrosion of the triboelectric material in the solid-liquid mode are inevitable. In addition, the devices in the fully enclosed mode have the disadvantages of complexity, low cost-effectiveness, and complex disassembly, which hinder its development and practicality. Herein, a non-encapsulated polymorphous U-shaped TENG for multiform hydropower harvesting with effective robustness is designed, which contains two joinable parts: one U-shaped multilayered TENG unit, and three trigger ends chosen according to actual requirements. The joinable design can directly reduce the waterproof treatment of U-shaped multilayer section, performance degradation caused by humidity, and effectively avoids electrostatic shielding caused by water and corrosion of triboelectric materials. Furthermore, different forms of hydropower collection, such as the energy of surface water wave, underwater wave/flow, and water droplet can be achieved using the corresponding trigger end. This study provides a feasible scheme for efficient and economical multiform hydropower collection based on triboelectric technology.