Wireless drive of a piezoelectric plate by capacitorlike structure in electric resonance with an inductor

Abstract

A new technique of wirelessly transmitting electric energy to piezoelectric components is explored. In the design, an ac electric field is focused to a piezoelectric plate placed between plate-shaped live and needle ground electrodes which form a capacitorlike electric field generator in series with an inductor. The transmission of electric energy is enhanced when the capacitorlike electric field generator and inductor are in electric resonance. Experimentally it has been found that the real output power delivered to the piezoelectric plate depends on the electrode pattern, vibration mode, and electrical load of the piezoelectric component and the electric field focused by the needle ground and live electrodes. When the operating frequency is close to mechanical resonance frequency of the piezoelectric plate operating in the thickness vibration mode, a maximum output power of 0.264W and energy conversion efficiency of 1.02% have been achieved with an input voltage 150Vrms and 10mm electrode separation.