Abstract: In this paper, the authors investigate the optimization of acoustic energy harvesting based on twodimensional phononic crystal consisting of water cylinders in mercury background with a point defect. The numerical results show that the acoustic waves are localized and energy can be harvested by using piezoelectric film. The position of the highest particle velocity predicts the optimum position and structure of the piezoelectric film. By introducing the third component in the point defect, the optimum acoustic energy harvesting is obtained. It is found that the low density of the defect cylinder is of great advantage to acoustic localization and energy harvesting.

Key words: phononic crystal, point defect, localization