Optimization scheme for piezoelectric energy harvesting in line-defect for 2D starlike hole-type phononic crystals considering waveguides

Abstract

Enhancement of elastic wave energy harvesting by utilizing a phononic crystal (PnC) is a hot topic in electroelastic systems. Piezoelectric energy harvesting (PEH) is implemented herein due to attaching a piezoelectric transducer (PZT) disk on a 2D starlike hole-type PnC with a line-defect. Waveguide and energy localization will lead to the amplification of harvestable mechanical energy using the opened complete bandgaps of the PnC. For a given line-defect PnC structure, two geometric parameters (diameter and thickness of the PZT disk) of the PEH device are found to be key factors to influence the energy harvesting performance. Therefore, the finite element method is used to obtain the optimal diameter and thickness of the PZT disk through the design of numerical experiments. Using the two optimal geometric parameters, the electric power amplification ratio of the present PEH device will be 26.7 times over that of the PEH device using a thin plate with the same outer dimensions.