Broadband energy-harvesting using a two degree-of-freedom vibrating body

In this letter, we introduce the concept and describe the realization of a two degree-of-freedom piezoelectric energy-harvesting device. The proposed system consists of a proof mass (i.e., a rigid body) and two cantilever beams; it can utilize both translational and rotational degrees of freedom. Therefore, it exhibits double power peaks and an increased frequency bandwidth, and it can generate power more efficiently than conventional vibration-based single degree-of-freedom devices.