Phononic crystals with decoupled different defects enhance energy localization and harvesting performance

Utilizing phononic crystals (PnCs) to enhance the performance of piezoelectric energy harvesting (PEH) devices is essential for addressing the self-power challenges of low-power devices. Building on prior research concerning incomplete line defect PnCs, this study presents a PnC designed with decoupled defects (i.e., point-defects and incomplete line defects). The dispersion curve, energy localization, and energy harvesting performance of this system were investigated. The results indicate that as the distance between the two subsystems (i.e., the incomplete line defect system and the point-defect system) decreases, all constructed supercells exhibit decoupling properties. Notably, when the distance between the two subsystems is reduced to two unit cells, the system demonstrates optimal broadband energy harvesting and localization performance, achieving a maximum output power of 9.49 mW. Compared to previous studies, this system exhibits superior broadband energy harvesting capabilities, with output electrical power increasing by a factor of 2.56 to 7.68. Consequently, the results of this study offer novel insights and strategies for enhancing the performance of PEH devices through the application of PnCs with multiple defects.