Hydrophobic microcapillary vent for pneumatic manipulation of liquid in muTAS

摘要

For integrated multi-step muTAS, pneumatic manipulation of liquid reagents is a promising way to minimize dead volume and contamination. In such a system, passive vent valves are required for positioning and mixing of reagent droplets. This paper presents design, fabrication, and testing of a novel microstructure named Hydrophobic Microcapillary Vent (HMCV). By utilizing the negative capillary action of aqueous liquid against hydrophobic microcapillaries, one can position the liquid accurately without sensors: a water droplet of 400 pL volume was successfully positioned using air pressure up to 30 kPa. Since the HMCV has no moving parts and can be fabricated by molding technique up to 30 kPa. Since the HMCV has no moving parts and can be fabricated by molding technique at low cost, it can be built in a disposable unit of microdevices.