可撓式高分子基板應用於數位流體平台之研究

Abstract

數位流體平台具有結構簡單、沒有可動零件，以及可程式操控等好處，已廣泛地應用在生醫檢測上。有別於先前皆採用硬式的基板製作數位流體元件，本研究提出在高分子基板上，開發可撓式的數位流體元件，不但具有原來的優點，還具有低價、可撓，和外形多樣的好處。首先，透過材料及製程的評估中，了解基板與材料的特性，並進行平面元件的傾斜測試與理論分析，確認可驅動液珠在曲面上移動的能力。其次，這裡對一種新式的非對稱電濕潤驅動原理進行探討，利用液珠在正負相反的電場下，有不同的接觸角的特性，驅動液珠在方形共平面電極上來回振盪運動，並利用此一特性，提出一種凸字形的非對稱電極設計，成功地在開放表面上，以振幅100 Vp頻率9 Hz的方波，驅動1.0 ul液珠進行單向23.6 mm/s的移動。最後，本研究利用可撓基板特性，提出一種可重複使用，以及隨插即用的界面設計，可應用在三維數位流體平台的模組化，使液珠可以在模組間互相傳遞。經由適當間隙控制和界面電極設計，實驗結果顯示液珠可以順利通過界面，並提出三種流體模組的設計，組合出三維環形流體平台，成功地展示模組化的流體平台，在120 VAC下驅動2.5 ul的液珠，在該平台以105.7 mm/s的速度移動。

Digital microfluidic platform has been widely used in the biomedical analysis due to its advantages of simple configuration, no moving parts, and programmable control. Different from previous studies on hard substrate, flexible polymer films are proposed to develop the digital microfluidic device. First, in feasibility study, material and fabrication procresses are evaluated. The device tests and analytical analysis are performed in tilted and flat conditions. Also, droplet transportation on curved surface is successfully demonstrated. Second, a new principle of droplet actuation, asymmetric electrowetting, is studied. Due to charge trapping of insulator at different polarities, droplet can be actuated to oscillate on square coplanar electrodes. By using this phenomenon, unidirectional pumping of 1.0 ul droplet with a speed up to 23.6 mm/s is successfully demonstrated on asymmetric coplanar electrodes when a 100 Vp and 9 Hz square wave is applied. At last, a reusable and plug-and-play fluidic interface is designed for droplet interconnection. In gap size investigation and fluidic interface tests, feasibility of droplet crossing the interface gap and pumping across the fluidic interface are validated. Three modularized components are designed for 3-D microfluidic ring. Finally, 2.5 ul droplet is successfully transported at a speed of 105.7 mm/s when 120 VAC is applied.