A Novel Stick-Slip Piezoelectric Actuator Based on a Bridge-Differential Lever Mechanism

This paper proposes a stick-slip piezoelectric actuator incorporating a bridge-differential lever mechanism (BDLM) with a high displacement amplification ratio to overcome the limited stepping stroke inherent in conventional designs. A matrix displacement method model is developed for kinematic analysis and structural parameter optimization of the BDLM, whose performance is further studied through finite element simulations. A prototype of the actuator is fabricated for experimental validation. The results demonstrate that the proposed actuator achieves a displacement amplification ratio of 20.1 and a stepping stroke of <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$271.5 \mu ~\mathrm{m}$</tex> while maintaining high positioning accuracy and compact size. Compared with conventional stick-slip actuators, the novel design effectively increases both stepping velocity and scanning speed without requiring high-frequency operation, reducing wear and control complexity. The proposed actuator offers a promising solution for applications requiring large strokes and high-precision positioning.