Ultracompact Ball Vibrating Triboelectric Nanogenerator for Maximizing Instantaneous Power Output in Minimized Size

The increased adoption of Internet of Things (IOT)‐based portable devices has called attention to the need for high‐output portable power supply. Portable electronics powered by batteries require additional processes, such as replacement or recharging, for continuous operation. Small‐sized triboelectric nanogenerators (TENGs), which have been investigated for real‐time power supply, are limited by low output owing to their small surface area and small surface charge. Therefore, a TENG device that can generate a high output for a real‐time power supply is necessary. Herein, an ultracompact ball‐vibrating TENG (UBV‐TENG) is reported. With output enhancement owing to the electron avalanche effect, the UBV‐TENG can generate an instantaneous peak power of up to 0.7126 W with a diameter of 5 mm and height of 20 mm. With comparing existing TENGs, the UBV‐TENG generated more than 3 times higher instantaneous peak power with smaller device size. Owing to its small size and high performance, the optimized UBV‐TENG can be easily utilized for portable human‐motion energy‐harvesting device, such as a self‐powered safety light, as demonstrated by fabricating a 2 cm × 2 cm self‐powered light emitting diode (LED) circuit that powers up to 120 LEDs with stacked structures.