大位移MEMS静电梳齿驱动器的设计及制作

Design and fabrication of MEMS comb-drive actuator with large displacement

文章提出了一种大位移低驱动电压的MEMS静电梳齿驱动器,对器件进行了设计、模拟、制作以及测试。梳齿驱动器的侧向不稳定性即侧向吸合现象限制了梳齿驱动器的最大驱动位移,发现侧向稳定因子S,随支撑梁刚度比ky/kx以及梳齿间隙g的增加而增加,随梳齿交叠长度的增加而减小;而驱动器的驱动电压随梳齿间隙的增加而升高。在以上研究的基础上,提出了一种采用小间隙无初始交叠、长度线性递增梳齿结构和高纵/横向刚度比的预弯曲支撑梁结构的梳齿驱动器。器件测试结果表明,驱动电压71V时,可以达到100μm的驱动位移,进一步测试表明,驱动器的基模共振频率为573Hz,Q值为35.88。

The design, simulation and performance tests of a comb -drive actuator with displacement up to 100μm at driving voltage lower than 75V is presented. As the maximum displacement of comb - drive actuator is restricted by electromeehanical side instability namely side pulling effect, analysis of side stability, S, are developed to enlarge the displacement. It was found that the S may increase with the increasing suspension stiffness ratio ky/kx and comb gap, but decrease with the engagement area, while driving voltage decreases with the increasing comb gap. Based on these principles, a comb-drive actuator with small comb gap, high- stiffness-ratio prebent suspension beams, non -initial overlap and linear-engaged-length comb teeth is proposed. Experiments indicate that the actuator resonates at 573 Hz with Q factor of 35.88 and reaches the maxi- mum displacement over 100μm at driving voltage of 71V.