Broadband Energy Harvesting using Multi-Cantilever based Piezoelectric

Abstract

Wideband energy harvesting is essential particularly for extracting electrical energy from ambient vibration which is random. Researches show that the frequency bandwidth of the harvested energy can be effectively enhanced by using multiple cantilevers with different resonant frequencies connecting together. This paper investigates the effect of the different electrical configurations towards the output of the piezoelectric array. An array of four similar piezoelectric cantilevers was mounted side-by-side to operate as a system in generating electrical output across frequencies range up to 500 Hz. The resonant frequency of each of the cantilever was varied by introducing a proof mass of 0.15g, 0.50g and 1.00g at the tip of the cantilever. The result shows improvement in the frequency bandwidth of the piezoelectric array, where it is widened to 150 Hz with improved gap when connected in alternating polarities configurations. The piezoelectric array produces higher voltage when connecting in series configuration; but higher power when connecting in parallel configuration.