Piezoelectric energy harvesting using defect induced cruciform shaped phononic crystal with multiple bandgaps

Although numerous studies have been directed toward the piezoelectric energy harvesting using phononic crystals, generating high voltage output remains challenging. This is mainly due to the difficulty in optimizing the bandgap to enhance energy amplification. This paper presents a novel design of the phononic crystal structure to enhance voltage generation and overall energy harvesting efficiency. This study presented a phononic crystal that has a unit cell of the cruciform flower shape, enabling the formation of multiple broadened bandgaps that are essential for capturing the vibrations. The wave propagation and energy harvesting performance of the phononic crystal are numerically evaluated using single- and double-defect configurations. The obtained results show that the proposed design effectively increases the multiplicity of the bandgaps. Thus, it results in strong defect mode localization, which generates multiple voltage peaks at various frequencies. The highest peak voltage of 230 V is recorded for the double-defect configuration. The findings of this study hold promise for advances in sustainable energy strategies.