Frequency dependence of piezoelectric vibration velocity

Five piezoelectric series bimorph actuators with different lengths were measured to examine the effect of frequency on vibration velocity. It is found that the vibration velocity is frequency dependent. In low-frequency range, the mechanical and electrical losses are lower, and the actuator is able to achieve a higher vibration velocity approaching the mechanical limitation. On the contrary, in high-frequency range, the velocity is limited by heat generation from the mechanical and electrical losses. The velocity obtained is lower than that achieved from the low-frequency actuators. Heat generation increases with frequency, mechanical stress and applied electric field.