Application, challenge and perspective of triboelectric nanogenerator as micro-nano energy and self-powered biosystem

As a new type of energy harvesting technology, the triboelectric nanogenerator (TENG) can convert distributed energy into electrical energy. It is widely used in various fields such as wearable devices, biomedical devices, Internet of Things (IoT), natural environment, etc. However, there are still some issues that need to be solved for the commercial implementation of TENGs. This review focuses on four major kinds of applications for TENG as the platform of harvesting micro-nano energy: in vivo, in vitro, living environment and wild environment. The challenges and feasible techniques facing TENGs are summarized in three aspects, including low energy output, immature manufacturing technology and unreliable service life. We also review the recent progress in the strategies for improving the output performance and robustness of TENGs, including but not limited to material optimization, device engineering and power management. The aim is to establish a feasible framework of TENGs from laboratory to engineering application. Finally, the future trend of TENGs' application in distributed sensors and biomedical devices has prospected as a promising micro-nano energy for guiding the next innovation researches.