MEMS高量程加速度传感器压膜阻尼效果分析

为实现一种高量程加速度传感器的近临界阻尼设计以提高其输出性能,采用有限元方法分别研究了阻尼带隙宽度、阻尼介质特性及温度等对器件冲击性能的影响。结果表明:器件冲击响应是受迫振动与悬梁固有振动叠加;随着阻尼带隙变宽,悬梁固有振动渐突显,峰值电压增加;阻尼介质粘滞系数越大,其峰值电压越低;介质温度对器件输出特性影响不大。在常温空气介质中,过载保护曲面平移距离为0.5μm时,阻尼比为0.24,近临界阻尼,输出电压高达77.9mV。

Analysis on the Squeeze-film Damping Effects of a Novel High Accelerometer

In order to realize the critical damping design and further enhance the output performance of a high-g accelerometer,effects of the width of damping gap,the characteristics of damping medium and the temperature of damping medium on shock response of component were studied with ANSYS technology.Results obtained show that shock responses of the component are the superposition of forced vibration with high g shock and inherent vibration of cantilever.With the increase of damping gap width,the inherent vibration of cantilever become more obvious in output response and the peak output voltage increases.Under the same other conditions,with higher viscosity coefficient of damping media,peak voltage become lower.The relationship between the temperature of damping media and output response is not obvious.The parallel shift distance of overload protection curved-surface is 0.5 μm in air at room temperature,the damping ratio is 0.24,close to critical damping,and the output voltage is up to 77.9 mV.