A stick-slip piezoelectric actuator with large stepping displacement

Abstract

Piezoelectric actuators have gained widespread attention for their quick response, low energy consumption, and resistance to electromagnetic interference. However, current piezoelectric actuators face challenges in achieving large stepping displacement within compact spaces owing to the small output of individual piezoelectric elements. To address this issue, a stick-slip piezoelectric actuator based on the lever and triangular coupling amplification principle is proposed in this study. The improved lever and triangular amplification mechanisms significantly enhance the forward displacement during the stick stage. Owing to the unique slender flexible driving foot design of the triangular amplification section, the coupled triangular amplification mechanism can store elastic potential energy during the stick stage without compromising structural compactness. This energy is then released during the slip stage to counteract the sliding friction, enabling the actuator to achieve a sudden increase in characteristics. The displacement amplification effect of the flexible hinge mechanism is examined through theoretical calculations and simulations. The experimental results confirm that the proposed actuator can achieve large stepping displacement and high stepping performance factors under low-frequency conditions. Specifically, at a voltage of 100 V and frequency of 10 Hz, the stepping displacement and stepping performance factor reached 144 μm and 1.44 μm/V, respectively. Owing to the increased stepping displacement, the actuator achieved a maximum speed of 99.1 mm/s at 800 Hz. These features demonstrate the tremendous potential of the proposed actuator in various applications.