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.

The cardioid crank rocker mechanism is a mechanism obtained by replacing the crank of a crank rocker mechanism with a cardioid crank. The cardioid crank is a planetary mechanism capable of generating cardioid curves. Using the cardioid crank as the driving crank of the crank rocker mechanism is equivalent to a crank with variable speed and length moving along the cardioid line, changing the motion characteristics of the rocker. The motion characteristics of the cardioid crank rocker mechanism are studied, and the limit position of the rocker and the calculation method of the intermittent interval is given. The influence of the planetary linkage length and center distance on the intermittent interval, and how to complete the mechanical design with known intermittent angle are discussed respectively, and a comprehensive analysis is made.