Electronic View of Triboelectric Nanogenerator for Energy Harvesting: Mechanisms and Applications

Harvesting energy from rain, waves, and river flows has been an old problem for over 100 years. Hydropower is capable of the features of huge quantity, low cost, and renewability. To date, the investigations on triboelectrification have shed a light on flexible and sufficient energy harvesting methods from hydropower or ambient motions. A triboelectric nanogenerator (TENG) has become the most promising energy harvesting system in recent years. Herein, the background of hydropower is first introduced to highlight the urgent need of novel energy conversion devices. Meanwhile, the detailed working principle of contact electrification (CE) is summarized by focusing on the origins of charge and how such a charge is induced. With systematic studies, the common modes of charge generation systems are well investigated. Then, the fabrications of various types of CE‐based devices are introduced with the potential modifications to achieve high applicability in specific circumstances. In addition, the multifunctional devices for distinctive energy harvesting processes constructed by TENG are also reviewed. Due to real‐time response to environmental variation, TENG‐based self‐powered sensors and wearable healthcare devices have also become promising candidates in the scientific field as well as different aspects of daily life.