Acoustic energy harvesting using an electromechanical Helmholtz resonator

Abstract

This paper presents the development of an acoustic energy harvester using an electromechanical Helmholtz resonator (EMHR). The EMHR consists of an orifice, cavity, and a piezoelectric diaphragm. Acoustic energy is converted to mechanical energy when sound incident on the orifice generates an oscillatory pressure in the cavity, which in turns causes the vibration of the diaphragm. The conversion of acoustic energy to electrical energy is achieved via piezoelectric transduction in the diaphragm of the EMHR. Moreover, the diaphragm is coupled with energy reclamation circuitry to increase the efficiency of the energy conversion. Lumped element modeling of the EMHR is used to provide physical insight into the coupled energy domain dynamics governing the energy reclamation process. The feasibility of acoustic energy reclamation using an EMHR is demonstrated in a plane wave tube for two power converter topologies. The first is comprised of only a rectifier, and the second uses a rectifier connected to a flyback converter to improve load matching. Experimental results indicate that approximately 30 mW of output power is harvested for an incident sound pressure level of 160 dB with a flyback converter. Such power level is sufficient to power a variety of low power electronic devices.

Vibration Energy Harvesting: Machinery Vibration, Human Movement and Flow Induced Vibration

“…It generated an open circuit voltage of 15mV pp under the airflow of 1.6kPa. Liu et al (2008) demonstrated the development of an acoustic energy harvester using Helmholtz resonator. It uses a piezoelectric diaphragm to extract energy.…”

Current Developments of Energy Scavenging, Converting and Storing in WSNs

“…Acoustic energy harvesting performs conversion of acoustic energy into electrical energy by using piezoelectric transduction [54]. Piezoelectric and electromagnetic based acoustic energy harvesters are developed [55].…”

Modeling and enhancement of piezoelectric power extraction from one-dimensional bending waves

“…Yet, little effort has been given to exploit the energy of traveling waves in fluids and structures. Only a few research groups have studied this area with a focus on polarization-patterned piezoelectric solids [17], quarter-wavelength resonators [18], Helmholtz resonators [19][20] and phononic crystals [21][22][23][24]. In addition, Yang et al [25] combined the sonic crystal concept with the Helmholtz resonators to enhance the acoustic energy harvesting.…”