A Long Stroke Electromagnetic $XY$ Positioning Stage for Micro Applications

In this paper, a Lorentz force-based $XY$ positioning stage with a stack of four electromagnetic linear motors in parallel configuration is presented. The overall design of the positioning stage consists of a mobile and a fixed part separated using a four-point contact technique. The uniqueness of the proposed positioning stage lies in its light design with the ability to perform variable strokes at short $(< 100 \mu$ m) and long range (millimeter level) with preembedded auto guidance feature. The analytical modeling and experiment have been realized. The open- and closed-loop performance of positioning stage in linear and nonlinear trajectories have been tested and good agreement is observed between experimental and analytical results. The positioning stage is able to perform variable strokes up till 2 mm in the $xy$ plane. In closed loop, the maximum precision errors in short and long strokes are found to be 0.031 and 0.451 μm, respectively. The maximum travel speed is 12 mm/s in open loop.