An Elastic Energy Storage Method for Achieving Efficient Stick-Slip Motion in Piezoelectric Actuators With Small-Mass Movers

The miniaturization of precision instruments directly leads to a reduction in the mass of the mover in stick-slip actuators. As the mover mass decreases, inertia is reduced, making it difficult to overcome sliding friction and sustain efficient stick-slip motion. To address this challenge, the effect of mover mass on the single-step characteristics of the actuator is investigated, and accordingly, a novel elastic energy storage method is proposed. This method stores elastic potential energy during the stick stage and releases it during the slip stage, providing the necessary elastic recovery force to counteract sliding friction and achieve burst motion, thereby enhancing performance under low-inertia conditions. A rotational actuator based on this method is proposed, and its feasibility is analyzed. Experimental results show that the actuator with elastic energy storage enhances forward displacement during the stick stage and enables burst motion during the slip stage, improving overall stick-slip performance. At 150 V, the actuator achieves a forward displacement of 3.28 mrad during the stick stage and a 1.97 mrad burst displacement during the slip stage, resulting in a total stepping angle of 5.25 mrad. At 60 V, smooth motion is maintained with a single-step efficiency of 13%.