Analysis of electromechanical coupling coefficient for piezoelectric bimorph cantilever based on energy method

LIU Xiang-jian

（School of Mechanical and Electrical Engineering，Jinling Institute of Technology，Nanjing 211169，China）

Abstract：In order to solve the problems of the piezoelectric effect of the piezoelectric bimorph cantilever，the energy method was investigated. After the analysis of the electromechanical coupling coefficient for piezoelectric bimorph cantilever，the theory model of the electromechanical coupling coefficient for piezoelectric bimorph cantilever was established. The theory model was validated by experiments and the relations between the electromechanical coupling coefficient for piezoelectric bimorph cantilever and structural parameters and material characteristics were simulated. The results indicate that the optimal thickness of the piezoelectric bimorph cantilever is 0.25 mm obtained by theory analysis，which is consistent with the experimental results. Moreover，with the increasing of thickness ratio，the electromechanical coupling coefficient increases. Meanwhile，with the increasing of elastic modulus ratio，the electromechanical coupling coefficient increases and beryllium bronze flexible substrate harvester is superior to the steel flexible substrate harvester.