The Novel Design and Fabrication of Polymer Based Structures for 2X2 MEMS Optical Switch

[[abstract]]在過去十年來，語音與數據資料的需求使得光通訊元件的需求大增。在光通訊 元件中，光開關用來作為切換光訊號之路徑、光纖網路的保護機制。傳統機械式的 光開關，通常是利用步進馬達或繼電器等零件來推動光纖或利用反射鏡來造成光路 的轉換，其缺點為尺寸較大、切換速度較慢、不易組裝與對光，不易與其他元件整 合，無法滿足光通訊的高效率與密集度之需求。微機電式光開關因有高精度、小尺 寸與低成本的因素漸漸廣為使用。本計畫改良傳統之2X2 雙穩態微機電式光開關， 使用聚對二甲苯材質，取代矽於雙穩態之彎曲結構中。由於楊氏係數約僅為矽的五 十分之一，在相同條件下，Parylene 材質之雙穩態彎曲樑機構將比矽質之相同機構 可以大幅減少進行位置切換之驅動力，可以簡化光開關/致動器的設計，降低致動器 的數目，從而減少光開關的尺寸，而結構所受之最大應力仍小於降伏強度。本研究 有系統的分析與製造新型2X2 光開關，從設計端的雙穩態與致動器理論分析，運用 模擬軟體Coventorware 進行動態模擬與最佳化設計，到製造加工與量測，驗證本研 究之可行性。[[abstract]]During the past decade, the demands of voice and data boosted the development of optical communication components. Within the optical communication components, optical switches are utilized as optical signal route changing, network protection. Traditional optical switches use step motor or relay as the switching mechanism. However, the drawbacks of larger size, low switching speed, poor assembling/integration with other components limit the future application and development. MEMS optical switches have merged the advantages of high precision, small size and low cost, regarded as the future trend of optical switches. In this study, instead of tradition silicon bistable beams, the novel Parylene based bistable beams have proposed for 2X2 MEMS optical switch. Due to the Yang＇s modulus of Parylene is about 50 times smaller than that of silicon, in the same condition, the Parylene bistable mechanism requires much less driving force. It is easy to simply the optical switch/actuator design, reduce the number of actuators, and then reduce the size of optical switch, while the driving force is low, and the maximum stress is still smaller than yield strength. This study presents a systematic design methodology to accomplish a new micro bistable mechanism for 2X2 MEMS optical switch. The theory analysis of bistable beam and actuator, dynamic simulation, and optimization, are carried out to identify the innovation of new micro bistable mechanism design, and then the experiments and measurements prove the feasibility.[[note]]NSC99-2221-E327-03