Wetting micro- and nanofluidic devices using supercritical water.

We describe a method for wetting micro- and nanofluidic devices with water or any other pure liquid. The process is performed by enclosing the fluidic device in a liquid-filled cell, heating the cell to a temperature above the critical point of the liquid, and subsequent cooling of the cell to room temperature. Because the process liquid is essentially a gas during wetting, arbitrary shapes can be wetted. We demonstrate wetting of micro- and nanostructures in a fused-silica device with only a single inlet. The process is low-cost, fast, safe, and very reliable.