一种静电驱动微机械变形反射镜

Electrostatically actuated microelectromechanical deformable mirrors

以ANSYS软件的有限元分析为依据对变形反射镜结构模型进行研究,探讨各主要结构参数及驱动电压对变形位移的影响。考虑静电驱动力、张力和空气阻尼衰减对变形镜回复过程的影响,建立一种复合参数模型来预测变形镜的瞬态行为。结果表明,驱动器的弹性薄板厚度、跨度和电极间距明显影响变形位移;驱动器的变形位移随驱动电压的增加出现稳定的非线性增加和不稳定的“拉入”现象;驱动电压撤除后镜面回复时间短,重复性好。

The mechanics of the mirror was analyzed using the finite element package ANSYS to show the effect of the structural parameters and actuated voltages on the deflection of the actuator. A lumped parameter model was developed for predicting the transient motion of mirrors, taking into account electrostatic and tensile forces and viscous air damping via squeeze film theory. The results show that the elastic membrane thickness, actuator span and gap spacing have a strong effect on the deflection, the actuator undergoes the deflection increasing nonlinearly at voltages below pull-in voltage and snap through instability at voltages above pull-in voltage when subjected to a voltage ramp, the re-set time and repeatability are attractive when the actuated voltage is set to zero.