Leaf-Like TENGs for Harvesting Gentle Wind Energy at An Air Velocity as Low as 0.2 m s~(?1)

摘要

Existing technologies for harvesting electrical energy from gentle windface an enormous challenge due to the limitations of cut-in and rated windspeed. Here, a leaf-like triboelectric nanogenerator (LL-TENG) is proposedthat uses contact electrification caused by the damped forced vibration oftopology-optimized structure consisting of flexible leaf, vein bearing plate,and counterweight piece. The effectiveness of the topology-optimized leaflikestructure is studied, which solves the problem of reduced output due toelectrostatic adsorption between the leaf surfaces while reducing the cut-in(0.2 m s~(?1)) and rated wind speed (2.5 m s~(?1)). The LL-TENG unit having smalldimensions of 40 cm~(?2) (mass of 9.7 g) at a gentle wind of 2.5 m s~(?1) exhibitsoutstanding electrical performances, which produces an open-circuit voltageof 338 V, a short-circuit current of 7.9 μA and the transferred charge densityof 62.5 μC m~(?2) with a low resonant frequency of 4 Hz, giving an instantaneouspeak power of 2 mW. A distributed power source consists of the fiveLL-TENGs in parallel is developed by designed self-adaptive structure, forwhich the peak power output reaches 3.98 mW, and its practicability anddurability are successfully demonstrated. This study is a promising distributedpower source technology to drive electronics in gentle wind outdoorenvironments.