電動力操控應用於微液滴細胞晶片之研究

Abstract

電動力是一跨尺度的操作力量，本研究將之應用於實驗室晶片，成功地將電動力同時操控數位微流體及生物微粒子。其中數位微流體系統是一種以非連續之微液滴作為液體傳輸單位的微流體系統，其主要優點包含不需流道設計與製程簡單等等。而介電泳是細胞實驗室晶片領域中操控生物微粒子之非常重要的技術，利用微電極所產生的不均勻電場可對細胞等生物分子進行分離、濃縮、定位等操控技術。本研究以整合介電泳技術於數位微流體系統為目標。

本研究以電濕潤技術發展數位微流體系統，進行微液滴傳送之測試，配合電訊號、元件材料、及液滴操作環境的改變，討論微液滴傳送之機制及生物應用。此外，發現了非對稱電濕潤現象，探討其理論基礎並發展為液滴傳輸系統。同時也發展介電泳操控技術，結合微電極設計及理論模擬計算，了解介電泳的理論及應用。最後，整合電濕潤數位微流體系統及介電泳細胞操控技術於同一晶片，成功地設計並製作不含機械結構且以電動力操控之微液滴細胞濃縮晶片。

Electrokinetic force is a cross-scale manipulation mechanism. In this research, we applied the electrokinetic force in Lab-on-a-Chip and demonstrated its cross-scale manipulation abilities by driving microdroplets and bio-objects.

Microdroplets are the basic units in a digital microfluidic system. In such a system, microdroplets are transported individually in channel-less structure, which simplifies the fabrication processes. Dielectrophoresis (DEP) force had been demonstrated in separating, concentrating, locating, and orientating bio-objects by non-uniform electric fields generated by energized microelectrodes. The goal of this research is to integrate the DEP technique into the digital microfluidic system.

In this research, electrowetting-on-dielectric (EWOD) phenomenon was adopted as the actuation force of microdroplets. We examined the transportation of microdroplets by varying electrical signals, device materials, and filling media. Asymmetric EWOD (AEWOD) phenomenon was observed and applied in an unidirectional microdroplet pumping device. Besides EWOD-based microdroplets actuation, the simulation of DEP field and DEP manipulation of mammalian cells were also investigated under different microelectrode designs. Finally, we successfully developed a microdroplet-based cell chip as a cell concentrator by integration of EWOD and DEP technologies.