An Endurable Triboelectric Nanogenerator for Wind Energy Harvesting Based on Centrifugal Force Induced Automatic Switching between Sliding and Rolling Modes

Triboelectric nanogenerator (TENG) is a potential way of utilizing environmental wind energy for clean electric power. However, the TENG in contact mode produces severe abrasion during continuous operation, which seriously affects the durability of the friction layer and electrical stability, thereby restricting its practical application. Aiming at the above problems, an embedded spring and metal slider structure TENG (SM-TENG) is designed. The SM-TENG automatically switches from sliding to rolling modes due to the centrifugal force, which greatly improves mechanical durability and electrical stability. The electrical output performance is essentially stable, even after 550,000 runs. Additionally, the speed threshold for mode switching can be decreased to 120 rpm by adjusting the size of the stiffness coefficient of the spring. The SM-TENG can supply energy to various commercial sensors at a rotational speed of 90 rpm, light up 232 light-emitting diodes (LEDs), and recharge a 47 uF capacitor to 3 V in 15 s. This paper describes a strategy to resolve some problems related to poor electrical stability and mechanical durability caused by the abrasion of the TENG friction layer material at a high speed. In addition, the SM-TENG exhibits huge potential for application in the Internet of Things in the underdeveloped region.