Evaluation of dynamic displacement characteristics of a piezoelectric composite using a laser interferometer

1-3 type piezoelectric composites were fabricated by using a dicing saw to cut grooves in poled PZT and then filling in these grooves with polymer. The vibration characteristics of the PZT and the polymer sections comprising this piezoelectric composite were measured with a laser heterodyne Interferometer. In the polymer sections, a phase delay occurs under initial vibration because of contraction of the PZT in the lateral direction. This phenomenon becomes increasingly obvious as the elastic modulus of the polymer decreases. With a lower elastic modulus of the polymer, the amplitude of vibration of the PZT increases. The amplitude of vibration of the polymer, however, increases when the elastic modulus of the polymer is appropriate