CMOS Energy Harvester Based on a Low-Cost Piezoelectric Acoustic Transducer

This paper describes an approach for harvesting electrical energy from a low-cost piezoelectric generator using a CMOS energy processor. The generator consists of an ordinary piezoelectric buzzer and a steel ball bonded onto it. The device mechanically behaves as a spring-mass system. Mechanical vibrations are converted into electric power by a PZT layer. The energy processor has an expected maximum efficiency of 55% for an output power of 198.21 ¿W. The efficiency and the amount of generated energy by the low-cost converter are comparable to other authors' results. Furthermore, the design of a CMOS charge controller is presented and its simulation results are discussed. The integrated circuit has the function of controlling the charge delivered to a 1.2Vdc battery.