Study of a piezoelectric switching circuit for energy harvesting with bistable broadband technique by work-cycle analysis

In this article, a piezoelectric energy harvesting device comprises a bistable vibrating cantilever beam and a switching-type interface circuit (synchronized switching harvesting on an inductor) is proposed, and the resulting performance is compared to the traditional linear technique. It was known that the synchronized switching techniques increase efficiently the output power of the piezoelectric energy harvester for low-coupled structures. However, the traditional piezoelectric energy harvester based on a cantilever beam is only efficient at resonance. To broaden the available bandwidth, a bistable nonlinear technique was proposed. In this article, the bistable technique and synchronized switching harvesting on an inductor interface are combined together to accomplish a more efficient broadband piezoelectric energy harvester. The power flow and work cycles are adopted to simplify the analysis of the switching techniques and then summarize the increasing performance of the nonlinear piezoelectric harvester. Finally, simulation results and experimental validations show that the proposed integrated device owns larger bandwidth and collects more harvested energy.