Design, Fabrication and Testing of a Dual-Range XY Micro-Motion Stage Driven by Voice Coil Actuators

Nowadays, compliant micro-motion stages offer high positioning accuracy and repeatability. When assembled with conventional stages, the resulting dual-range positioning systems allow for nanometer scale accuracy within a centimeter scale working area. However, such systems invoke a high cost and large footprint. This paper presents a low-cost, compact compliant XY micro-motion stage where dual-range manipulation has been implemented in an effort to maintain the workspace area and increase the positioning accuracy. The method presented in this work employs the use of a large range/low resolution linear encoder to measure the position of the stage (coarse positioning), before using short range/high resolution capacitive sensors to correct the positioning error (fine positioning). This solution achieves a positioning accuracy close to 1μm within a workspace of ±2.2mm×2.2mm. The compliant stage has been machined from Aluminium 7075-T6 using Wire Electric Discharge Machining (WEDM). This material is well known for its large reversible strain and its suitability for compliant mechanisms.