A compact structure and high-speed actuator designed by imitating the movement of wave

By imitating the natural phenomenon of waves pushing leaves, a compact novel wave-type piezoelectric actuator is proposed in this paper. Compared to traditional inchworm piezoelectric actuators, it combines the clamping unit and driving unit into an arc-shaped flexible driving foot (AFDF). Clamping and driving functions are realized by alternately controlling two ends of the AFDF using two piezoelectric stacks (PESs). One motion unit instead of two makes control simpler, the structure more compact and a faster movement speed. The static model of the AFDF is developed to characterize the mapping laws between structural dimensions and actuator amplification ratios, and the dynamic model represents the relationship between the control signals and move displacements, thus demonstrating the feasibility of the actuator. Finally, a prototype was fabricated, and a testing system was set up to conduct performance evaluations of its motion capabilities. At the driving frequencies of 370 Hz and 380 Hz, the maximum forward and reverse motion speeds can reach 4.345mm/s and 4.537mm/s, respectively. In the range of 0.1–10 N, there is no significant change in motion speed, and it has good stability. Its resolution for forward and reverse motion can reach 106 nm and 109 nm, respectively.