A friendly approach to increasing the frequency response of piezoelectric generators

A wide bandwidth piezoelectric generator (PZG) was constructed and tested experimentally. The PZG was characterized using chirp and wideband random excitations. The experimental results showed that by proper shaping of an attached cantilever beam it is possible to increase the number of vibration modes of the PZG and, hence, to improve the effectiveness of the energy harvesting as compared with a conventional cantilever PZG configuration. The proposed structure was designed to produce 3 vibration modes, which extend the operation around the frequencies 35Hz, 57Hz and 76Hz. As a result, the bandwidth was widened by a factor of 2.81 as compared with a conventional harvester.