Ultrasonic Energy Transference Based on an MEMS ZnO Film Array

An ultrasonic energy transference system with a ZnO square piezoelectric thin-film array (SPTFA) structure is presented. The design principle of the system is analyzed, and a device with the SPTFA structure is successfully fabricated based on MEMS processes. The characteristics of the energy transference system are investigated in detail. The experimental results reveal that the resonant frequency of the system is 13 MHz, the maximum voltage of the receiving end reaches 10.87 V when the amplitude of excitation voltage is 10 V, at that time the output power of system is 5.377 mW, and power density is 2.581 mW/cm². The light emitting diode is lit successfully by the system in a distance of 3 mm.