An Ultrarobust and High-Performance Rotational Hydrodynamic Triboelectric Nanogenerator Enabled by Automatic Mode Switching and Charge Excitation.

The triboelectric nanogenerator (TENG) is an emerging technology for ambient mechanical energy harvesting, which provides a possibility to realize wild environment monitoring by self-powered sensing systems. However, TENGs are limited in some practical applications as a result of their low output performance (low charge density) and mechanical durability (material abrasion). Herein, an ultrarobust and high-performance rotational TENG enabled by automatic mode switching (contact mode at low speed and noncontact at high speed) and charge excitation is proposed. It displays excellent stability, maintaining 94% electrical output after 72 000 cycles, much higher than that of the normal contact-mode TENG (30%). Due to its high electrical stability and large electrical output, this TENG powers 944 green light-emitting diodes to brightness in series. Furthermore, by harvesting water-flow energy, various commercial capacitors can be charged quickly, and a self-powered fire alarm and self-powered temperature and humidity detection are realized. This work provides an ideal scheme for enhancing the mechanical durability, broadening the range of working frequency, and improving the electrical output of TENGs. In addition, the high-performance hydrodynamic TENG demonstrated in this work will have great applications for Internet of Things in remote areas.