Damping models for microcantilevers, bridges, and torsional resonators in the free-molecular-flow regime
Damping models for microcantilevers, bridges, and torsional resonators in the free-molecular-flow regime
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DOI：
10.1109/jmems.2008.916321
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发表时间：
2008-04-01
影响因子：
2.7
通讯作者：
Zalalutdinov, Maxim K.
中科院分区：
文献类型：
--
作者：
Martin, Michael James;Houston, Brian H.;Zalalutdinov, Maxim K.
在低压下工作的微机械谐振器的主要减振模式是与气体颗粒的碰撞。本文提出了一种简单的模型，用于确定垂直、水平和扭转运动的微悬臂梁、桥和桨形谐振器的阻尼和品质因数，采用一致的气体-表面相互作用模型，工作在自由分子流区。这些模型包含了诸如壁温、容纳系数和高纵横比等影响。最后讨论了振动速度接近气体颗粒热速度的极限情况，分析表明，这些模型在振动峰值速度达到0.2c之前都是有效的，其中c是气体的热速度。
The dominant damping mode for micromachined resonators operating at low pressures, typically 1000 Pa or less, is collisions with gas particles. This paper presents simple models for determining the damping and the quality factor of micro-cantilever, bridge, and paddle resonators in vertical, horizontal, and torsional motion, using a consistent model of gas-surface interaction, operating in the free-molecular-flow regime. These models incorporate effects such as wall temperature, accommodation coefficients, and high aspect ratios. Finally, the limiting case of vibrational velocities approaching the thermal velocity of the gas particles is considered, with analysis showing that these models are valid until the peak velocity of the vibration reaches 0.2c, where c is the thermal velocity of the gas.