A boundary-reconfigurable flexure-based piezoelectric actuator with selectable inchworm and stick-slip driving modes for multi-condition cross-scale precision positioning

Abstract Stick–slip and inchworm piezoelectric actuators are both capable of cross-scale precision positioning, while exhibiting distinct advantages. Stick–slip actuators offer high-speed motion with simple driving schemes, whereas inchworm actuators provide large thrust and superior load capacity. Therefore, integrating these complementary driving mechanisms to adapt to multiple working conditions is highly desirable for cross-scale positioning applications. However, existing dual-mode approaches typically rely on multiple actuation units, resulting in increased system complexity and reduced compactness. To address this issue, this article presents a boundary-reconfigurable flexure-based piezoelectric actuator that enables selectable inchworm and stick–slip configurations within a unified and compact structure. By mechanically reconfiguring the fixed nodes of the flexure mechanism, the boundary constraints and deformation patterns are altered, leading to reconfigurable displacement transmission paths from the piezoelectric actuator to the mover. As a result, two distinct driving mechanisms are achieved: a stick–slip mode for high-speed positioning and an inchworm mode for high-thrust positioning. A prototype is developed, and the effectiveness of boundary reconfiguration has been experimentally validated. The proposed actuator provides a compact solution for multi-condition cross-scale precision positioning.