静电刚度式谐振微加速度计设计

运用梁的横向振动特性分析了梁振动频率与平行板电容形成的静电刚度的关系，并以此设计了静电刚度式谐振微加速度计。在加速度作用下，检测质量产生的惯性力使电容器极板发生位移来改变电容结构的间隙大小，从而使谐振频率发生变化，通过检测频率变化量来测量输入加速度的大小。根据加速度计的工作原理说明检测过程中梁的机械刚度保持不变，只与产生静电刚度的电容间隙变化相关，减小了检测信号对机械误差与残余应力的依赖性。运用加工参数进行理论计算得出加速度计的灵敏度为21．17Hz／gn，在CoventorWare2005中进行仿真表明：加速度计的固有频率为23．94kHz，灵敏度约为20Hz／gn，与理论设计值相近。

Design of resonant micro accelerometer based on electrostatic stiffness

Relation between frequency and electrostatic formed by parallel capacitors is analyzed by characteristics of laterally librating beam,and resonant micro accelerometer based on electrostatic stiffness is design by using this relation.The inertial force on mass block caused by external acceleration induces the movement of moving plate of capacitor,resulting a shift of gap changes the resonant frequency of beam,so the acceleration can by measured by measuring the shift of frequency.The operating principle of accelerometer indicates that the mechanical stiffness is constant during sensing,and only related to the change of gap,which decreases the dependence on the mechanical error and residual stress of beam.Analysis indicates accelerometer's natural frequency is 23.94 kHz under electrostatic stiffness,sensitivity is 20 Hz/g n,which is coincident with the theoretical value 21.17 Hz/g n.