Evaporation driven pumping for chromatography application.

A continuous transport process for liquids in micro-channels is reported. Flow was generated by evaporation at the channel end plus capillary forces. The micro-channels integrated into a two-glass-layer device were 110 microm wide, 28 microm deep and 4 or 10 cm long. A continuous liquid transport velocity of up to 2.25 mm s(-1) was observed for aqueous solutions. The flow velocity is shown to increase when an air stream is guided over the evaporation zone.