出平面微致動器應用廣泛，其中利用雙金屬效應達到出平面致動之設計，由於製程簡單，所以被大量採用。然而此類致動器在操作時多半只能單向致動，且會因不同材料間的界面受到剪力作用導致脫層現象，而降低元件之使用壽命。為了有效解決此問題，本文提出採用單一結構層來製作可雙向致動之單層薄膜出平面微電熱式致動器。
本文所提之微致動器是由四根互相平行且截面大小相同的桿件所構成，而內部兩根桿件和外部兩根桿件有一個高度差。當電壓施加在內部的兩根桿件時，則因內部兩根桿件有較大的熱形變量，致使結構產生出平面向上的運動；反之若將電壓施加在外部的兩根桿件時，則會使結構產生出平面向下的運動。經由有限單元模擬以及實驗驗證，其具有操作電壓可低於5V、元件壽命長且至少可致動109次仍無明顯的性能改變、製程容易以及位移量大等優點，將可應用於微繼電器、可變電容及微光學掃描系統等領域。

Out-of-plane electro-thermal actuators have been applied to a variety of fields. Among them, the actuators whose driving method is bi-metal effect have the advantage of simple fabrication processes and are thus most commonly used. However, such an actuator experiences a shear force at the interface of different materials, while actuated. Delamination consequently takes place and therefore decreases its lifetime. In an attempt to overcome the drawback inherent in a bi-metal actuator, a novel bi-directional out-of-plane electro-thermal actuator of single layer thin film material is proposed.
The presented actuator comprises four parallel, identical beams. The two inner beams connect the two outer beams with a step, which enables the inner beams and the outer ones located at different planes. While a current only flows through the inner beams, they would experience a temperature rise; the accompanying thermal expansion therefore enables the actuator to bend upwards. On the contrary, while a current only flows through the outer beams, the actuator would bend downwards. The bi-directional out-of-plane motion is thus achieved. The design was examined in light of finite element analysis. The potential application lies in micro-relays, variable capacitors, and optical scanning system.

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