The Application of Electrode Design in Vibrating Piezoceramic Plate for Energy Harvesting System

Abstract

The energy harvesting system of piezoceramic plate is studied on the electrode configuration to improve the electromechanical transferring efficiency. The piezoceramic plate is used to perform the vibration characteristics by experimental measurements and finite element method (FEM). Thereafter, the dynamic characteristics and the electromechanical coupling efficiency of the piezoelectric energy harvesting system are studied by the electrode design method of the piezoceramic plate. Several experimental techniques are used to measure the dynamic characteristics of piezoceramic plate. First, the full-filed optical technique, amplitude-fluctuation electronic speckle pattern interferometry (AF-ESPI), can measure simultaneously the resonant frequencies and mode shapes for out-of-plane and in-plane vibrations. Second, the pointwisely measuring system, laser Doppler vibrometer (LDV), can obtain resonant frequencies by dynamic signal swept-sine analysis. Third, the correspondent in-plane resonant frequencies and anti-resonant frequencies are obtained by impedance analysis. The experimental results of vibration characteristics are verified with numerical calculations. Besides the dynamic characteristics of piezoceramic plates are analyzed in converse piezoelectric effect, the direct piezoelectric effect of piezoceramic plates are excited by shaker to generate the electric voltage. It has excellent consistence between resonant frequencies and mode shapes on the vibration characteristics by experimental measurements and finite element numerical calculations. In this study, the Electrical Potential Gradient (EPG) calculated by FEM is proposed to evaluate the electromechanical coupling efficiency of piezoceramic plate on the specific vibration mode. The correspondent electrode configuration, which is designed by EPG, can produce the best electromechanical transfer both in direct and converse piezoelectric effects. It is concluded that the vibration characteristics of piezoelectric materials have excellent consistence determined by experimental measurements and FEM.