Recycling Piezo-Crystal Based Sounders from Small (Electronic) Devices into Energy Harvesting Devices

Abstract

Many small devices now incorporate a sound feedback device using piezo crystal plates of varying sizes (10mm-20mm diameter). After these devices are discarded, the piezo crystal plates are usually of no value other than a curious toy or component. This work presents a potential use of this device (18.8mm diameter unimorph PZT 5H piezo plate) for harvesting energy by mounting it on the wrist (at the base of meta carpal) of human subjects. The subjects were made to walk at an average steady pace of 0.7m/s. The device generated voltage in the range of 180.4mV to 1674.60mV. ANSYS 10 simulation shows that the optimum voltage will be generated at resonance frequency of approximately 204Hz.