Designing a phononic crystal with a large defect to enhance elastic wave energy localization and harvesting
Xian’e Yang, Jiahui Zhong, Jiawei Xiang
Abstract
Phononic crystals (PnCs) have been shown to manipulate and amplify elastic waves. Using this characteristic of PnCs to assist energy harvesting has a remarkable effect. Generally, a defect occurs when a unit cell in a PnC is replaced by another cell with different geometric or material properties; then the output electric power of piezoelectric energy harvesting (PEH) devices will be significantly enhanced. In this study, a cross-hole-type PnC-assisted PEH device with a large defect is presented by replacing several adjacent cells with other cells. It is found that multiple peak voltages can be created within the bandgap and multimodal energy harvesting can be performed. Compared with the defect mode composed of a small defect, energy localization and amplification of the proposed PnC leads to substantial enhancement of harvesting power after tailoring the geometric parameters of a PEH device. This work will help in designing PnC-assisted PEH devices in a reasonable way.