Design of an electrostatic 2-axis MEMS stage with large area platform for PSD

Recently the electrostatic 2-axis MEMS stages have been fabricated for the purpose of an application to PSD (probe-based storage device). However, most of them have low area efficiency, which are undesirable as data storage device since all of the components (springs, comb electrodes, anchors, platform, etc) are placed in-plane. In this paper, the authors presented a novel structure of electrostatic 2-axis MEMS stage that is characterized by having large area platform. For large area efficiency, the actuator parts mainly consisting of comb electrodes and springs are placed right below the platform. In this article, the structure and driving principle of the MEMS is described, followed by design procedure, structural and modal analysis using FEM (finite element method). The area efficiency of the MEMS stage was designed to be about 55%, which is very large compared to conventional ones.