本論文探討介電電濕式(electrowetting on dielectric)微流體元件的設計與製作。此元件展現即時微流體系統的潛能，並且能應用於實驗室平台晶片(lab-on-a-chip)、微全分析系統(micro total analysis system)。而微小化後的元件則有：減少樣本(sample)的體積、低成本、可拋式以及可攜帶性等優點。 本文以介電電濕法來製作微流體系統元件。首先，液滴在不同性質表面的接觸角被提出來討論。其次，比較傳統型、覆晶型與所提出改良型製程之優缺點。再來探討一維(1-D)與二維(2-D)的介電電濕元件在不同的介電層、不同的通道間距與不同濃度的鐵氟龍(DuPont Teflon® AF)溶液情況下，元件操作的情形。本文製作的介電電濕式微流體系統元件，在透過電漿輔助化學氣相沉積系統(PECVD)所成長出的介電層，其在大氣環境下的操作電壓約為35伏特。而微流體系統四種基本的操作模式也在此實驗中展現。此外，由螢光棒所分離出來的兩種液體，研究兩種不同的液滴在合併後內部混合的現象。最後，藉由這兩種液體混合後所發出的螢光，提出一種利用介電電濕微流體元件所構成的去氧核醣核酸(DNA)雜交反應(hybridization)元件與其反應速率的即時監測系統。 This thesis reports the design and fabrication of an electrowetting on dielectric (EWOD) microfluidic device that has the potential to demonstrate technologies for real-time microfluidic system applications in lab-on-a-chip (LoC) or micro total analysis system (µTAS). In such a way, the merits of miniaturized device are much smaller volume of samples, low cost, disposable, and portable. The microfluidic system is based on the principle of EWOD. First, contact angles of droplets on different surface were discussed. Second, the fabrication of EWOD devices by the conventional and the flip-flop processes were compared with the improved process and their advantages and disadvantages were also discussed. Third, 1-D and 2-D EWOD devices were tested for various fabrication parameters including materials for dielectric layer, gap spacing, and concentration of Teflon® AF. With the dielectric layer deposited by PECVD, the driving voltage of the EWOD-based microfluidic system was around 35 V in air environment. In experiments, the four fundamental operations of microfluidic system were carried out in the EWOD device. In addition, two droplets extracted from the light stick were applied to investigate the mixing process in real time. To the end, a novel configuration for real time monitoring on DNA hybridization reaction rate was proposed on the base of the EWOD microfluidic device.
