微致動器是今日微機電系統(MEMS)中一項很重要的部分，在各個應用領域中均扮演了一個具有決定性的角色。過去已有許多不同形式及驅動方式的微致動器被提出，但是大部分的微致動器只有單一個運動方向，或侷限於與基板(substrate)平行的平面。若要達成兩個方向的致動則需利用多組一維微致動器的組合來達到目的，但是卻有佔據過大晶片面積的缺點，因此，使得他們的應用層面備受限制。
為了改善前人的缺點，本論文設計並製造出一能夠分別進行二維軌跡運動，且能達到出平面運動(out-of-plane)的微致動器；其橫方向位移是利用熱驅動來達成、垂直方向的位移則是利用平行板間靜電力來致動。本文中也包含理論分析與模擬結果來驗證可行性，且將兩者的結果比較。其中元件模擬是利用國家高速電腦中心所提供之微機電模擬軟體MEMCAD來進行，希望能藉由模擬的結果觀察不同的電壓和位移量大小的關係，配合利用槓桿原理所致動的垂直運動行為，並觀察本微致動器的運動軌跡。利用表面微細加工的方式製作出此元件，對其運動情形進行量測以觀察是否達到所預期的結果，最後，並與理論、模擬的結果加以比較，並探討其間的差異。

In this study, an electro-thermal microactuator for bi-directional motion is designed and fabricated using surface micromaching processes. The in-plane horizontal motion of the device is based on the uneven thermal expansion of the structure with different beam widths, while the out-of-plane vertical motion is driven by electrostatic force through using the principle of lever to allow bending the beam upward and to enlarge the tip deflection. This microactuator has the advantages of CMOS-compatible, low operation voltage, and simple fabrication processes. The expected applications for the proposed devices are micro switches, micromanipulators, micro optical tweezers, etc. Finite element method (FEM) analysis is used to simulate the electro-thermo-mechanical behavior of the device and to demonstrate the feasibility of our design for bi-directional motions under different applied voltages. The relationship between the applied voltage and the displacement is found, and the performance of the presented design has been examined. Finally, the deviation between simulated and measured results is discussed.

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