Experimental Study of Resonant Frequency Tunable Piezoelectric Energy Harvester

Abstract

Abstract. To improve energy harvesting performance, a resonance frequency tunable piezoelectric (PZT) energy harvester for vibrating applications was presented and investigated experimentally. A piezoelectric vibrational energy harvester (PVEH) consisted of a piezo-cantilever with a permanent magnet at its free-end and another excitation magnet fixed on vibration structure. The two magnets are placed with the same magnetic poles facing each other to produce repulsive force. The cantilever has dimensions of 70x10x0.6mm3, clamped 10mm, and two magnets sized ø10x4mm3. The testing results show that the magnetic force, denoted by the initial separated distance between the magnetic dipoles (SDMD), exerts great influence on the generated performance. With the SDMD increasing from 15mm to 40mm, the generated voltage rises from 24.4V to 40V, and the resonant frequency increases from 33.75Hz to 38.75Hz.