A Bionic Stick-Slip Piezoelectric Actuator With High Single-Step Efficiency Inspired by Kangaroo’s Leg Mechanics

To achieve high single-step efficiency (SSE), a novel bionic stick-slip piezoelectric actuator inspired by kangaroo's leg mechanics is proposed in this article. The bionic design incorporates an elastic drive mechanism that mimics the kangaroo's tendon and foot function, effectively storing and releasing elastic potential energy. By employing a single piezoelectric stack, the actuator enhances the stepping displacement in both the stick and slip phases. The forward displacement during the stick phase is enhanced by the displacement coupling amplification principle, while sudden increase characteristics during the slip phase are achieved through elastic energy storage in the stick phase. Finite element analysis confirms the effectiveness of the flexible hinge mechanism, demonstrating good displacement amplification. Experimental results show that the designed actuator has good single-step characteristics under low-frequency conditions. Specifically, at an input voltage of 60 V, the maximum SSE reaches 38.6%. At an input voltage of 150 V, the maximum stepping angle is 29.56 mrad. Due to the improved stepping angle, the actuator reaches a maximum angular speed of 21.51 rad/s at 500 Hz. These characteristics demonstrate the efficient driving capability of the designed actuator as well as its potential applications in precision devices such as aerospace and miniature robotics.