Nonlinear behavior in piezoelectric ceramic transducers

In recent years intensive development efforts have been devoted to new piezoelectric high-power devices, such as ultrasonic motors, piezoelectric actuators, and piezoelectric transformers. Piezoelectric ceramic transducers used in these devices are usually driven at a high level of vibration stress in a resonant mode. To optimize the performance of such devices, it is essential to understand the nonlinear behavior which appears in the relatively higher power range for a transducer. This nonlinear behavior has not yet been thoroughly studied, however, because a method for measuring it in a resonant mode has not been widely accepted. In this review an electrical transient response method that allows observation of nonlinear behavior in a resonant mode was introduced. The dependence of electromechanical characteristics on vibration stress under electric field-free conditions in lead-zirconate-titanate ceramics was discussed.