【摘要】 为消除静电吸引型微镜因存在静电吸合效应而导致的短路现象,基于电场的非均匀分布可以产生静电排斥力的原理,设计了一种静电排斥型六边形微机械反射镜.微镜包含7组驱动电极,最大的一组驱动电极由镜面和其正下方的六边形下电极组成,其他6组分别位于微镜的各条边上,其中3组为梳齿结构,另外3组为U形弹簧,镜面由3组U形弹簧支撑.利用有限元软件对微镜频率响应和暂态响应特性进行了仿真,结果表明谐振频率高达7kHz,暂态响应时间小于0.0003s.利用表面硅工艺加工出了样片,并用白光干涉仪对其静态位移特性进行了测试,在50V直流电压下微镜位移量为0.7μm.由结果可知该微镜可消除静电吸合效应.故该微镜不仅可用于对反射光进行光程和相位的调制,也可用于自适应光学系统中波前畸变的校正.更多还原

【Abstract】 A micromirror actuated by electrostatic repulsive force was presented to eliminate the pull-in effect which may result in a short circuit of a conventional electrostatic attractive microelectromechanical system(MEMS)micromirror.The design is based on the principle that an asymmetric electric field can generate a repulsive force.The micromirror consists of seven pairs of electrodes.The largest pair consists of a hexagon micromirror and the bottom hexagon electrode right below it.The other six pairs are located on each side of the micromirror,three of them are comb fingers and the other three are U-shaped springs which are also used to support the micromirror.The resonant frequency and transient response time simulated by finite element analysis(FEA)are 7 kHz and 0.000 3 s,respectively.The prototype was fabricated by a surface micromachining process and successfully tested using a white light interferometer,and the displacement is 0.7 μm at 50 V.Results show that the microerror can eliminate the electrostatic pull-in effect.Furthermore,it can not only be used to modulate the optical length and the phase of the reflect～ed beam,but also be used to correct wavefront aberrations in an adaptive optics system.更多还原