Design of a piezo-driven inchworm flexure stage for precision positioning

Positioning stage with high resolution and high stiffness are always required in the micro/nano manipulation. This paper presents the design, fabrication and experimental tests of a piezo-driven positioning stage based on the inchworm principle, which can provide a large motion range with high resolution and high stiffness. The positioning stage mainly consists of a monolithic compliant mechanism and four piezoelectric actuators, which form one linear driving unit and two clamping units with complementary structures. Two piezoelectric actuators connected in parallel are utilized to drive the linear moving section for high stiffness. To facilitate the parameter design, the analytical models are derived in detail and validated by finite element analysis. A prototype of the positioning stage is designed, fabricated and tested to further demonstrate the feasibility of the proposed idea. Experimental results well verify the effectiveness of the developed design.