Enhanced energy localization and harvesting by design of phononic crystal defects

Abstract

A new arrayed phononic crystal (PnCs) with defects is proposed. The supercell method is used to calculate the band structures. Energy localization can be found around the defects and energy harvesting (EH) can be realized by the attachment of piezoelectric patches around the designed defects. The EH can be concentrated on the frequency of 64–64.1[Formula: see text]kHz with output voltage of 8.22[Formula: see text]V. By the change of the piezoelectric patch from circular to oval shape, the frequency of EH can be changed. By the optimization of geometric shapes of piezoelectric patches and the optimal design of unit cell, the EH output voltage can be increased to 4.21 times higher than the original state and the EH frequency band is effectively broadened. The amplification factor can be increased to 327.13.