Surface-directed channels filled with organic solvents.

Although channels of microfluidic devices are normally pipes, some groups have recently studied surface-directed channels. These channels were created between two stacked glass slides that were physically flat but chemically patterned. The working fluids used for such channels were mostly water solutions, though organic solvents are important in some applications such as organic synthesis. In this study, novel surface-directed channels were developed, which could contain various organic solvents including xylene, nitrobenzene, and dimethyl sulfoxide. The glass slides used for these channels were previously ground by an abrasive and treated with (tridecafluoro-1,1,2,2-tetrahydrooctyl)trimethoxysilane. Xylene continuously flowed through a 1 mm wide, 40 mm long, and 0.14 mm deep channel at flow rates up to 99.99 microL min(-1).