結合介電濕潤與光定義表面自由能致動及留置微液滴

Abstract

本論文利用介電濕潤與光定義表面自由能材料，藉由將介電濕潤元件上之疏水層置換成光定義表面能之疏水材料，達成微流體晶片上致動微液滴及留置微液滴。在介電濕潤元件上，表面自由能是可以被光定義及電壓所控制。經由深紫外光 (Deep UV)曝光製作不同比例的親疏水區域，微液珠可被表面自由能的梯度所驅動及留置。此介電濕潤元件包含主動與被動，兩種制動方式。主動驅動即為藉由施加介電濕潤電壓來致動液滴，而被動驅動則是滴定於光定義區域上的液珠會被足夠的表面自由能梯度所驅動及流經光定義區域上的液珠會被足夠的表面能所留置。藉由施加介電濕潤於光定義表面自由能之材料表面，具有節能、自我對準、致動液滴、留置液滴及不易整合電壓操控液滴的特性。研究過程中，設計主動驅動之介電濕潤電極及被動驅動之石英光罩，在留置微液滴的實驗，成功地將在移動中的液滴，依表面能的差異留置更微量之液滴，微量液滴約為20 nL。

We propose droplet actuation and retention by electrowetting-on-dielectric (EWOD) force and photo-definable surface free energy. By utilizing a photo-definable surface energy material as a hydrophobic dielectric in an EWOD device, surface free energy is photo and electrically controllable. Microdroplet can be driven and retention by the gradient of surface free energy which is achieved by using different ratio of hydrophobic and hydrophilic area through deep UV (DUV) exposure. Hence, the reported device drives droplets actively by EWOD and passively by photo-defined surface free energy. We designed electrodes for EWOD and quartz mask for photo-definable material. We succeeded to retention a 20 nL droplet on a photo-defined high surface energy from an EWOD-driven droplet. By applying EWOD on a material whose surface energy is photo-definable, powerless droplet actuation, droplet self-alignment, droplet retention, and electrically droplet driving not be easily integrated.