Analysis and Design for the Nano-positioning XY-Stage Based on the MEMS Technology

In order to realize nano-positioning for operating on the micro-object under the nano-scale condition, the paper presented a novel single crystal silicon (SCS) nano-positioning micro XY-Stage, which bases on the technology of Micro Electro Mechanical Systems (MEMS) and integrates with the functions of drive and detecting position. This XY-Stage is fabricated on a single-crystal-silicon by combining the technology of the deep reactive ion etching (DRIE) at silicon with anode bonding processes. Lateral electrostatics comb drive is used as driving power to drive the movable stage in the x-direction and y-direction and the displacement of the movable stage is detected by the position sensors. Then the signals derived from the sensors are used to build up the closed-loop control to improve the XY-Stage positioning precision. Especially, each comb-drive actuator adopts pull-pull mode to increase the electrostatic force. The developed XY-Stage of 2000times2000 mum² is suspended in the center of the chip by four sets of folded beam, detecting beam and bending flexure composite springs. The paper modeled the structure and used finite element method (FEM) to analyze the structure of the XY-Stage, maximize moving distance, resonant frequency and modal shape of the XY-Stage. The simulation and analysis result showed that under 30 V driving voltage, the efficient driving force is 649.8 muN and a 13.5 mum moving stroke in each of four directions. Simultaneity, the mechanical coupling is very small (0.0114 mum); and the first-order resonant frequency is 1121 Hz, above of all verified the XY-Stage is reasonable and practical further.