A method for filling complex polymeric microfluidic devices and arrays

This paper describes an improved method for filling microfluidic structures with aqueous solutions. The method, channel outgas technique (COT), is bas ed on a filling procedure carried out at reduced pressures. This procedure is compared with previously reported methods in which microfluidic channels are filled either by using capillary forces or by applying a pressure grad ient at one or more empty reservoirs. The technique has proven to be > 90% effective in eliminating the formation of bubbles within microfluidic netwo rks. It can be applied to many devices, including those containing PDMS-ter minated channel features, a single channel inlet, and three-dimensional arr ays.