Design of piezoelectric bimorph for collecting both bending and torsional energies

Piezoelectric materials have been widely used in transducers to convert mechanical deformation to electrical energy for power scavenging applications. Piezoelectric energy harvesting in bimetallic cantilever configuration is the most popular approach which scavenges mechanical energy predominantly from bending motions. A new piezoelectric cantilever design is proposed, which consists of a piezoelectric layer being split into two separate parts and a supporting substrate. This design enables energy conversion in both bending and torsional motions, which expands the bandwidth of harvesting devices and increases the energy converting efficiency. Structural optimization for the new design is conducted using a commercial multiphysical FEM (finite element method) software. Static and dynamic simulations of the proposed structure have been conducted, and the results are discussed and presented in this paper.