Small size piezoelectric impact drive actuator with rectangular bimorphs

A new small size linear type piezoelectric inertia-friction actuator has been developed. The actuator is self-inertia type and operation principle is based on the impact drive. Piezoelectric actuator has simple design and consists of four rectangular bimorph piezoelectric plates fixed in two metal holders that are connected by the two springs. Actuator can operate as self-moving slider on the clamped carbon fiber reinforced plastic rod or it can be clamped to drive the rod. Size of the actuator is 8 × 8.5 × 5.6 mm. Excitation of the actuator can be carried out by single saw tooth or rectangular pulse type signal. Bidirectional motion of the slider is achieved by changing phase of the saw tooth electrical signal by π or duty ratio of the rectangular pulse signal. Numerical investigation of the piezoelectric actuator was performed to analyze natural frequencies, modal shapes and response of the actuator to the different excitation signals. A prototype piezoelectric actuator was made and operating principle of the actuator was validated. Measurements of electrical and mechanical output characteristics were performed. The maximum no load velocity of the slider reaches 40.376 mm/s with driving voltage of 40 V. Actuator achieves maximum thrust force of 0.21 N with the same input voltage.