Selective Hydrophobic and Hydrophilic Texturing of Surfaces Using Photolithographic Photodeposition of Polymers

The control and localization of small volumes of aqueous solutions inside miniature reactors is a topic of growing significance. A simple control method relies on patterning regions of different wetability that define and guide the liquid spread within these systems. In this paper photolithographic photodeposition is demonstrated as a technique for texturing patterned surfaces.. Hydrophobic surfaces are created by selectively photopolymerizing trifluorochloroethylene gas (C2F3Cl) through a quartz mask. Similarly, hydrophilic surfaces are created via acetylene (C2H2) photopolymerization. These surfaces are demonstrated to provide a simple and effective means of fluidic control and localization.