Polydimethylsioxane fluidic interconnects for microfluidic systems

This paper presents novel polydimethylsioxane (PDMS) based interconnects for microfluidic systems with a low dead volume. Through-hole type and "lceil" type PDMS interconnects have been designed, fabricated, and tested for glass and plastic capillary tubing. Oxygen reactive ion etching and epoxy bonding methods are employed to bond PDMS interconnects to different substrate materials including silicon, glass, polymer and other thin film materials. Leakage pressure, leakage rate, and pull-out force are characterized for these interconnects. For reusable PDMS interconnects, the maximum leakage pressure reaches 510 kPa (75 psi) and the maximum pull-out force is about 800 mN. For nonreusable PDMS interconnects, the maximum leakage pressure is found to be 683 kPa (100 psi) and the maximum pull-out force is 2 N. For both types of PDMS interconnects, the leakage rate test demonstrates that the leakage is not detectable at a working pressure of 137 kPa (20 psi).