Recent Progress in Flow Energy Harvesting and Sensing Based on Triboelectric Nanogenerators

Triboelectric nanogenerators (TENGs), as a novel energy harvesting technology, have attracted increasing attention. This review paper focuses on the application of TENGs in flow energy harvesting and self-powered flow sensing systems, as well as the latest research progress in this field. First, the working principle of TENG is introduced in detail, including the electrification mechanism and four basic working modes. Subsequently, the common applications of TENG-based flow energy harvesting are systematically classified and summarized. In addition, the designs and principles for harnessing wind energy, wave energy, water flow energy, and droplet energy are illustrated individually. Furthermore, the common applications of TENG in flow sensing are elucidated, involving flow velocity and direction, flow rate measurement, respiration monitoring, water level, and wave motion monitoring. Finally, the current challenges in this field, such as the stability of TENG performance, scalability and integration, environmental impact and durability, etc., are discussed and future research directions, such as developing new TENG materials and designing more high-efficiency TENG structure, are proposed. It is hoped that this review paper can actively promote the research and application of TENGs and contribute to the development of this field.