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Motion speed is an important parameter of stick-slip piezoelectric actuators. However, most of the existing stick-slip piezoelectric actuators achieve a high motion speed by operating under a quite high driving frequency. Operation under high frequency will affect the motion stability and as well accelerate the wear of the contact surfaces. To realize relatively high speed under a relatively low operation frequency, here a specific L-shape flexure hinge was employed to design the stick-slip piezoelectric actuator. Its structure design, working principle and processes, structure parameter selection, and output performances were studied in detail. The experimental results indicated that the designed actuator could achieve a maximum motion speed of 16.67 mm s −1 under the driving frequency of 800 Hz. This operation frequency was much lower than those employed in previous actuators for achieving a similar motion speed. By comparative analysis, it was shown that the designed actuator also maintained good minimum stepping displacement and loading capacity. These features would be useful for the practical applications of stick-slip piezoelectric actuators.

In order to reduce the regression phenomenon of the piezoelectric stick-slip actuator, and improve the output performance, a piezoelectric stick-slip actuator with regular octagonal flexible hinge mechanism is proposed in this paper. The pseudo-rigid body method is used to analyze the regular octagonal flexible hinge mechanism and the flexible driving foot respectively.A prototype is fabricated to test the working performance and the results demonstrate that the minimum step is 0.01μm, the maximum speed is 145251μrad/s, and the maximum load carrying capacity is 500g. The experimental results show that the parasitic motion suppresses the regression of the actuator and improves the output stability.

Backward motion commonly exists in the stick-slip linear piezoelectric actuator, resulting in deterioration of the output performance and limiting their applications. To solve the problem, a stick-slip linear piezoelectric actuator with suppressed backward motion, achieved using an active-locking mechanism (ALM) with two mechanisms, is proposed in this paper. One mechanism involves stick-slip driving, while the other actively suppresses backward motion by clamping the slider during the backward driving process through efficient control. A prototype actuator was designed and manufactured to verify the feasibility of this method, and an experimental system was established to obtain the detailed parameters. Also, to verify the feasibility and effectiveness of the suppression effect on backward motion of the proposed actuator, the output performance of the traditional stick-slip actuator and the actuator with the ALM were compared. Based on the results, we demonstrate that the maximum output speed and maximum output force of the prototype are 2.26 mm s−1 and 1.6 N under a voltage of 100 V, respectively.

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