A piezo-actuated nanopositioning stage based on spatial parasitic motion principle

This paper presents the configuration, design, and characteristic analysis of a novel two-degree-of-freedom stickslip nanopositioning stage based on the spatial parasitic motion principle. The planar-spatial evolution process is proposed to develop a compliant tripod mechanism by which the spatial parasitic motion can be generated for dual-axis actuation. An X-shaped hinge configuration is designed by freedom and constraint space analysis and introduced to the mechanism to improve the loading capacity of the nanopositioning stage. The actuation principle for driving along X- and Y-directions forward and backward is provided. The chain-based compliance matrix method is adopted for kinematic and static modeling of the compliant tripod mechanism. The dominant parameters are determined based on sensitivity analysis, and the performance of the stage is further studied by finite element method. The nanopositioning stage prototype is fabricated and assembled, and experimental investigations are conducted. The proposed nanopositioning stage has maximum velocities of 0.77 mm/s and 1.03 mm/s along X- and Y-direction, and a loading capacity of 5 kg can be achieved. Furthermore, the coarse-fine positioning experiments are carried out, and the positioning resolution is measured to be 18 nm.