Scavenging breeze wind energy (1-8.1 ms-1) by minimalist triboelectric nanogenerator based on the wake galloping phenomenon*

Harvesting low-speed wind energy is challenging for existing technologies. In this work, we developed a wakegalloping-driven triboelectric nanogenerator (TENG) (named WG-TENG) to effectively harvest breeze wind energy when the wind speed is as low as 1 ms-1. The unique dynamics feature of wake galloping effect enables the proposed device a simple structure (minimalist contact-separation mode), low onset wind speed, lightweight (8.5 g), easy fabrication, and good portability. The relationship between the WG-TENG output performance and its structural parameters as well as bluff body geometries has been systematically studied. Attributed to the vibration enhancement realized by the wake galloping phenomenon and high efficiency of TENG at lowfrequency, the proposed harvester not only can be used to drive small electronics, but also realizes a highly sensitive real-time wind speed monitoring system. This work realizes a miniaturized and high electrical performance wind-driven TENG for practical applications.