Multi-layer Piezoelectric Energy Harvesters for Improved Power Generation

摘要

Abstract: Low power consuming sensor networks have drawn the attention of many researchers in the domain of energyudharvesting using smart materials. Piezoelectric smart materials have been extensively studied to transform the mechanical energy in the form of vibrations to electrical energy. There have been several attempts to improve the generated power by optimizing the harvester configuration and the processing electronics. In this paper, a multi-layer configuration of a cantilever based harvester is analyzed and compared with a bimorph configuration. Published models of bimorphs assume that the piezoelectric material covers the cantilever completely. This paper focuses on studying the partial coverage of piezoelectric material on the beam and analyzing the multi-layer configuration of the active material. It is observed analytically and experimentally that the multi-layer configuration is superior to the bimorphs when compared for the same volume of the piezoelectric material used. Experimentally, multilayer harvester and bimorphs made of Polyvinylidinefluoride (PVDF) are tested under similar conditions to observe that the multilayer harvester generates 230 μW/cm3/g2 which is more than twice the value obtained from bimorphs, thus demonstrating a better than 100% improvement in performance.ud