A MEMS-based wideband piezoelectric energy harvester system using mechanical stoppers

A piezoelectric MEMS energy harvester (EH) system with top- and bottom-stoppers can response to vibrations with frequency ranging from 30 Hz to 48 Hz when the top- and bottom-stopper distances are 0.75 mm and 1.1 mm, respectively, and the acceleration of vibration is 0.6 g. By adjusting the stopper distance, the operating bandwidth is broadened from the initial mechanical resonance of the PZT EH cantilever at 36Hz to various extent. Larger acceleration of vibration also leads to wider operating bandwidth.