Design Of Acoustic Energy Harvesting Device Based On Piezoelectric Element

Acoustic energy harvesting technology is one of the main directions for new energy research and development.Especially in recent years,the rapid development of micro-electromechanical systems and Internet of things technology,which promotes the emergence of wireless sensors,wireless communications,radio frequency identification(RFID)and embedded systems of low-power high technology advances by leaps and bounds,how to achieve this clean and pollution-free energy for low-power equipment can become a hot research topic of various countries in the world.On the account of this,this paper provides a sound energy harvesting device based on a Helmholtz resonator and a circular piezoelectric vibrator.The incident acoustic wave of the resonator is amplified by the Helmholtz resonator,and the amplified sound wave acts on a circular piezoelectric vibrator at the bottom of the Helmholtz resonator.The vibration of the circular piezoelectric vibrator is generated by the acoustic pressure and passes through the piezoelectric effect of the piezoelectric convert acoustic energy into electrical energy.The theoretical model of equivalent centralization parameter of a circular metal-substrate piezoelectric transducer with a piezoelectric sheet is established,the acoustic energy conversion principle of the acoustic energy harvesting apparatus is analyzed,and the influence of the piezoelectric sheet radius on the acoustic energy harvesting apparatus is studied.The simulation results show that the piezoelectric effect is the best when the radius of the piezoelectric film and the radius of the metal substrate is 0.8.The maximum output power is 12.7 ?W when incident sound pressure is 1 Pa(94dB),acoustic frequency is 1188 Hz and load resistance is 3.7 K?.In addition,this paper presents a new kind of acoustic energy harvesting device of Helmholtz resonator and piezoelectric cantilever beam,which cleverly uses the acoustic waveguide as the mass of the piezoelectric cantilever to achieve the effect of functional reuse.The new acoustic energy recovery device has good sound wave amplification and power generation effect,Experiments show that the sound wave can be amplified by 7 times under the resonance state.When the incident sound pressure is 2 Pa(100 dB),frequency of 150 Hz,the maximum output power of the sound energy recycling equipment is 2.4 ?W.