能量耗散在微機電系統(Micro Electro-Mechanical Systems, MEMS)是一件 重要問題，減少能量耗散可以提升 MEMS 的性能。MEMS 的微結構尺寸很 小，空氣對微結構表面造成的黏滯力相對於體積力來說非常顯著，而有許多 帶有質量塊 MEMS 器件，例如射頻(RF)、加速度計、光學開關、微扭轉鏡、 諧振器等，質量塊在空氣薄膜上運動會產生所謂的擠壓膜阻尼效應，因此減 少擠壓膜阻尼是一個提升 MEMS 性能最直接且有效的方法。 降低擠壓膜阻尼的方法為在質量塊上進行穿孔和對 MEMS 環境抽真空， 由於空氣的平均自由徑與微結構的尺寸相當，會造成流體的不連續性，產生 稀薄氣體效應，且穿孔處氣體的進出產生的末端效應會有能量耗散，另外， 質量塊及下方基板的材料也會因為製程的需求有所不同，空氣對於不同材料 表面會有不同的切向動量調節係數，以上三者皆會影響空氣的流動行為。因 此，本研究主要是在不同切向動量調節係數下，稀薄氣體效應和末端效應對 於穿孔板擠壓膜阻尼力的影響，並針對不同的穿孔形狀進行分析，提出四種 形狀(圓形、正六角形、正方形、正三角形)的穿孔修正分子氣膜潤滑方程式， 顯示在相同的穿孔面積下，圓形設計的穿孔板，所受到的阻尼力最小。

Energy dissipation is an important problem in Micro electro-mechanical Systems(MEMS). The dissipation mechanisms include thermoelastic damping, squeeze film damping, anchoring loss, etc. The main damping source is squeeze film damping(SFD). The method to reduce SFD is to manufacture perforated proof mass and evacuate air from the environment. Therefore, this study mainly focuses on the influence of rarefied gas effect and end effect on the flow rate with different tangential momentum accommodation coefficients. Based on the analysis of short pipe flow with different perforation shapes, the end correction lengths of four shapes with different tangential momentum accommodation coefficients are fitted, considering the rarefied gas effect and end effect.Four kinds of perforated modified molecular film lubrication equations (circle, hexagon, square and triangle) are proposed to analyze the damping coefficient of perforated plates. The results show that low tangential momentum accommodation coefficient of perforated plates and circular perforations cause small damping coefficient for perforated MEMS device

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