Structural design and analysis of a nano-positioning planar motion stage

This paper studies the structural design and analysis of a precision nono-positioning planar motion stage. First, the configuration design and specification of the planar motion stage are proposed. The stage consists of a stage base, a carriage supported by four air bearings, four linear motors, and a two-dimensional optical encoder. The planar motion stage has characteristics of high precision, long travel range, and nano-positioning accuracy. The travel range of the stage in X and Y directions are 50 mm × 50 mm. Then, structural characteristics of the stage are analyzed by finite element method (FEM). Deformation of the carriage due to inertial loading with 0.5g acceleration is analyzed. Natural frequencies and mode shapes of the carriage are analyzed and also checked by modal experimental test. Finally, optimum design method is applied to find the minimum weight of the carriage, and 34% of the carriage weight is reduced with maintaining the same carriage stiffness.