Optimization of bimorph cantilever based piezoelectric energy harvester for high efficiency

Abstract

Various attempts are being carried out to convert variety of ambient energies. Every conversion mechanism has its own limitations on efficiency. In this context, piezoelectric phenomenon found to be promising over electromagnetic and electrostatic considering mechanical oscillations in to useful electrical energy. In this work, we use piezoelectric effect because it has an advantage of high converting power efficiency and ease of application. Cantilever uses piezoelectric effect to harvest energy from load. Bimorph cantilever based piezoelectric energy harvester with three different materials; PZT-5A, PZT-8 and cadmium sulfide for three different proof mass patterns 3.5 µm × 2 µm, 3 µm × 2.5 µm, 2.5 µm × 3 µm in the frequency range 60 to –90 Hz and applied load of 100 N to 100 KN has been simulated using software tool COMSOL Multiphysics v 5.2. From the analyses of simulation results, PZT-5A material-based piezoelectric energy harvester with the proof mass dimension of 3.5 µm × 2 µm was found to exhibit maximum efficiency. The reasons for such high efficiency have been discussed in detail by means of physical properties of piezoelectric materials used, range of applied load and proof mass patterns.