Integration of a Cr–N Thin-Film Displacement Sensor into an XY Micro-stage for Closed-Loop Nano-positioning

In this paper, an attempt is made to integrate a compact strain gauge-type displacement sensor referred to as the Cr–N thin-film displacement sensor into the XY micro-stage designed in a small size of 25 mm (X) × 25 mm (Y) × 6.5 mm (Z) to achieve closed-loop nano-positioning of the stage. In the XY micro-stage, which has been developed in the previous study by the authors, Cr–N strain gauges for the Cr–N thin-film displacement sensors are directly fabricated on elastic hinges integrated into the stage structure so that the elastic hinges can be employed as sensors for stage positioning as well as guides for a stage table. In this paper, two types of the Cr–N thin-film displacement sensor having different layouts of the strain gauges, line patterns and land patterns are designed and fabricated. Computer simulation based on the finite element method is also carried out to evaluate the robustness of sensors against the external disturbances from electrical wires soldered onto a sensor surface. After some basic experiments, each of the developed Cr–N thin-film displacement sensors is integrated into the XY micro-stage, and its feasibility is evaluated in experiments.