An XY Nanopositioner With a Self-Adjusting Stiffness Center Module

This paper presents an innovative large stroke XY compliant nanopositioner with a self-adjusting stiffness center (SASC) module in order to minimize the in-plane parasitic rotation. Double parallelogram flexure is utilized to achieve kinematics decoupling. Moreover to realize SASC, an additional planar joint based on parallelogram flexure is adopted, which significantly reduces the in-plane moment. SASC design approach makes the stiffness center adjust by itself and stay fixed by the variation of the stiffness of parallelogram flexures when the stage is in motion. In a case study, a 1mm × 1 mm XY nanopositioner with a SASC module is presented in details. Finite element analysis (FEA) results show that the proposed XY positioner is capable to achieve the required millimeters stroke, and significantly reduces parasitic rotation with the SASC design.