US Patent 8444933 Microfluidic device and method of manufacturing the same

A microfluidic device includes a first substrate including a micro-flow path, and a valve seat protruding into the micro-flow path, a second substrate, coupled to the first substrate, and including a cavity corresponding to the valve seat, a first parylene layer disposed on an inner surface of the first substrate, and a valve gate film provided between the first substrate and the second substrate, such that the valve gate film opens and closes the micro-flow path with air pressure applied between the valve seat and the cavity, the valve gate film having a hydrophilic surface. A portion of the first parylene layer, which is disposed on a lower surface of the valve seat and contacting the valve gate film, has a hydrophobic surface.