针对纳米定位平台的构型和定位精度问题,采用体硅加工技术成功地研制出了一种基于单晶硅并带有位移检测功能的新型二自由度微型定位平台,定位平台采用侧向平动静电梳齿驱动。利用力电耦合和能量守恒原理分析了静电致动器的致动机理,对定位平台的主要失效模型、静态和动态特性进行详细建模分析,证明了静电梳齿力电耦合所导致的侧壁不稳定以及驱动器的最大稳定输出位移,给出了平台稳定工作条件下梳齿间隙、梳齿初始交错长度以及复合柔性支撑梁的弹性刚度比之间的关系。动态分析时考虑空气阻尼对平台的影响,给出了平台最大运行速度、位移及动态条件下的临界驱动电压并把分析结果应用于平台闭环控制。实验结果表明:驱动电压30 V时,平台稳定输出位移达10 μm,机械稳定时间仅为2.5 ms。

In order to realize the miniaturized nano-positioning stage, a novel 2-DOF Single Crystal Silicon (SCS) nano-positioning micro X-Y stage with the function of displacement detection is successfully developed by using silicon bulk-micromachining; the X-Y stage is drived by an electrostatics comb actuator. The theories of electromechanical coupling and energy conservation are used to analyze electrostatic actuated mechanism, X-Y stage static characteristic and X-Y stage dynamic characteristic. Some failure modes of X-Y stage are also presented and the electromechanical side instability and the stable travel range of comb-drive actuators are investigated. The stable travel range depends on the finger gap spacing, the initial finger overlap and the spring stiffness ratio of the compliant suspension. Additionally, by taking into account the effect of the air damping on the X-Y stage dynamic characteristic, the maximum velocity, stable travel range and critical driving voltage are given to an experiment on closed-loop control. The experimental results indicate that the analyzed characteristics are useful in the design and control of the micro X-Y stage. Under 30 V driving voltage, the single-axis displacement output is 10 μm, and the closed-loop step response is only 2.5 ms.