Investigation on the geometry of beams for piezoelectric energy harvester

This paper presents various designs of the cantilever based piezoelectric energy harvester, which is excited using mechanical vibrations at the fixed end. By varying the geometries of the cantilever beam; higher stress, strain and consequently higher voltage and power could be attained from the same piezoelectric material. The analysis of energy harvesters were done using COMSOL Multiphysics 5.3a. The stress, strain and frequency response of the beams were verified by analytical, numerical and experimental methods. The result shows that the inverted taper in thick and width and inverted taper in width types of beams generated 47.39% and 21.31% more power compared to the rectangular cantilever beam. The resonant frequency of the inverted taper in thick and width beam is 53.3% less than the rectangle beam.