Wind-Driven Leaf-Like Thin-Film Piezoelectric Harvester for Low Wind Applications

Abstract

Piezoelectric thin film power generators are one of the future scopes of alternative energy-harvesting sources. In this paper, a wind-driven thin film piezoelectric energy harvester is explored and reported for both parallel and reticulate venation as well as for without venation. The proposed harvester consists of a triangular-shaped cantilever, triangular leaf-like piezoelectric microthin film (PEMF) and a cantilever. The free end of the cantilever is fixed to the PEMF which is capable of harvesting wind energy by vibration. The leaf-like PEMF structure is 122 μm thick, made up of polyvinylidene fluoride (PVDF) coated with silver ink electrode on either side. In this work, the influence of wind velocity, vein structure and cantilever length on overall performance of the system is investigated experimentally. It is seen that under favorable conditions, leaf with reticulate venation showed more than 10% increase in voltage output than in parallel venation. It is found that an increase in cantilever length leads to a substantial increase in voltage output by promoting early onset of flutter. At a velocity of 10 m/s, a maximum open circuit voltage of 1.90 V and power output of 1.2 μW are obtained for L/Lb=1 for reticulate venation PEMF leaf.