Hybrid acoustic energy harvesting using combined electromagnetic and piezoelectric conversion

Abstract

This paper reports a novel hybrid acoustic energy harvester. The harvester utilizes both the electromagnetic and piezoelectric conversion mechanisms simultaneously to convert the ambient acoustical noise into electrical power for self-powered wireless sensor nodes. The proposed harvester is comprised of a Helmholtz resonator, two magnets mounted on a piezoelectric plate, and a wound coil located under the magnets. The harvester is characterized both under harmonic and real random acoustical excitations. In-lab, under harmonic acoustical excitation at a sound pressure level of 130 dB and frequency of 2.1 kHz, an optimum power of 2.86 μW (at 114 Ω optimum load) is obtained from electromagnetic conversion and 50 μW (at 1000 Ω optimum load) is generated by the piezoelectric harvester's part. Moreover, in real acoustical environment of a domestic electric generator the peak voltages of 40 and 123 mV are produced by the electromagnetic and piezoelectric portions of the acoustic energy harvester.

Energy Harvesting Research: The Road from Single Source to Multisource

“…Different kinetic energy conversion methods in combination are able to compensate each other, thus boosting the output power. Various types of kinetic (including fluidic) hybridization involving two energy conversion effects have been developed, including piezoelectric–electromagnetic, electrostrictive–electrets, piezoelectric–triboelectric, electromagnetic–triboelectric, piezoelectric–electrostatic, triboelectric–electrostatic, and piezoelectric–electrostrictive . Hybridization involving three kinetic energy conversion effects, piezoelectric–electromagnetic–triboelectric, has also been reported.…”

Electromagnetic Bridge Energy Harvester Utilizing Bridge’s Vibrations and Ambient Wind for Wireless Sensor Node Application

“…Electromagnetic energy harvester comprised of a beam, coil, magnet, and base support. When the harvester is excited, the beam starts vibrating and the magnet attached to the beam also starts moving relative to the coil, and due to the changing magnetic flux, a voltage is induced in the coil [52][53][54]. However, electrostatic energy harvester is made of two conductive plates which are parallel to each other.…”

Recent Developments of Acoustic Energy Harvesting: A Review

“…A hybrid AEH device, which integrates the piezoelectric and electromagnetic conversion approaches, was proposed by Khan and Izhar [39]. As shown in Figure 8, the air passage in the AEH device was specifically designed to minimize the air damping influence.…”