Compact compliant parallel XY nano-positioning stage with high dynamic performance, small crosstalk, and small yaw motion

Abstract

This paper presents a novel XY nano-positioning stage using a compliant parallel mechanism with small crosstalk and yaw motion. A parallel mechanism can implement multi-degree-of-freedom motion with a small footprint. However, this implies crosstalk between the motion axes. In an effort to reduce crosstalk and yaw motion, we proposed a novel flexure guide structure. The proposed stage consists of two flexure displacement amplifiers driven by piezoelectric actuators, two combined double four-bar flexure guides, and two additional parallelogram guides. To prevent the rotational deformation of one amplifier due to the transverse force of the other, we introduce an intermediate leaf spring at the output ends of the amplifiers. This new parallel mechanism is optimally designed based on an analytical model of the stage to assure small crosstalk and yaw motion. The analytical model is verified as being well-described using a finite element analysis. An XY nano-positioning stage of size 150 x 150 x 30 mm(3) is fabricated following the optimal design. Experiments are carried out to verify the static and dynamic performances of the proposed XY nano-positioning stage. The proposed stage has an X and Y directional motion range of 120 mu m in closed loop. The resolution of the stage is 3 nm in both the X and Y directional motions. The actual crosstalk and yaw were limited to 0.770 mu m and 13.5 mu rad, while in the optimal design they were estimated at 0.5 mu m and 15 mu rad, respectively.