Improved Acoustic Energy Harvester Using Tapered Neck Helmholtz Resonator and Piezoelectric Cantilever Undergoing Concurrent Bending and Twisting

This work seeks to put forward an approach to enhance the voltage generated by an acoustic based piezoelectric energy harvester. When a flexible triangular foil is attached perpendicular to the PVDF cantilever beam there is an increase in strain in the beam, also there is an increment in the acoustic pressure amplification rate of the Helmholtz resonator due to the dimensional modification of its neck. The integrated effects of these modifications of the harvester on the output voltage have been investigated. When sound incident on the surface of the neck of the resonator, an oscillatory pressure is produced in the cavity, which in turns vibrates the PVDF cantilever beam and voltage generates. By amending the structure of the PVDF cantilever with a polyester foil attached perpendicular to it, the cantilever is driven into concurrent bending and twisting by the cavity pressure and therefore makes a noteworthy increase in the output voltage (C) 2016 The Authors. Published by Elsevier Ltd.