基于变刚度悬臂梁的MEMS静电驱动器的动态响应优化

Dynamic Response Optimization of MEMS Electrostatic Actuator Based on Variable Stiffness Cantilever Beam

传统的微机电系统(MEMS)静电驱动器存在驱动电压高和超调振荡的问题,可动极板稳定在平衡位置前会发生持续的振荡,难以满足可变电容、光开关等应用领域的综合要求。针对上述问题,采用变刚度悬臂梁的设计,利用刚度随行程增大的特性抑制了极板吸合及释放过程的振荡现象,在缩短调节时间的同时,有效降低了器件的驱动电压。仿真和实验结果表明,当器件悬臂梁的刚度随位移由5N/m增大到35N/m时,在相同电压下,动态响应的调节时间减少了55.5%,在相同行程下,动态响应的调节时间减少了21%,对应的驱动电压减少了23%。

Traditional MEMS electrostatic actuators have the problems of high actuation voltage and overshoot oscillation.The movable electrode oscillates continuously before stabilizing at the equilibrium position;hence,satisfying the comprehensive requirements of variable capacitors,optical switches,and other applications is difficult.To solve the above problems,this study adopts the design of a variable stiffness cantilever beam.With the characteristic of increasing stiffness with travel,the oscillation phenomenon is suppressed.The actuation voltage is effectively reduced,and the transient time is shortened.The simulation and experimental results show that when the stiffness of the cantilever beam increases from 5N/m to 35N/m,the transient time of the dynamic response decreases by 55.5%under the same voltage and 21%under the same travel,and the actuation voltage decreases by 23%.