Topology Optimization of the Thickness Profile of Bimorph Piezoelectric Energy Harvesting Devices

Due to developments in Additive Manufacturing, the production of piezoelectric materials with complex geometries is becoming viable, enabling the manufacturing of thicker harvesters. Thus, in this article a piezoelectric harvesting device is modelled as a bimorph cantilever beam with series coection, with an intermediate metallic substrate, under plain strain hypothesis. Then the thickness of the piezoelectric material of the harvester is structurally optimized using a discrete topology optimization method. Different optimization parameters are varied to study the algorithm’s convergence. The results of the optimization are displayed and analyzed, to study the influence of the harvester's geometry and its different substrate materials on the harvester’s energy conversion efficiency.