Electromechanical Energy Conversion in asymmetric Piezoelectric Bending Actuators

Piezoelectric materials can be conveniently used to build actuators which convert electrical into mechanical energy and vice versa. In structures containing beam and plate members, piezoelectric patches are employed to control flexural vibrations and optimization of the design and placement of these patches has been a concern in the development of 'smart structures' and ultrasonic motors. Rather than looking at detailed models of particular systems, it is desirable to find an optimum design of a piezoelectric patch by general consideration of energy conversion in piezoelectric layers subject to bending deformation. The electromechanical coupling factor (EMCF) and the actuator power factor are measures for the actuators ability to transform energy and can be utilized as design criteria to determine an optimum thickness of a piezoelectric patch. Compared to current designs of bending actuators, results indicate that thicker piezoelectric layers lead to better energy conversion.