Novel interconnection technologies for integrated microfluidic systems

A new approach to realize silicon based integrated microfluidic systems is presented. By using a combination of silicon fusion bonding (SFB) and deep reactive ion etching (DRIE), multi-level fluidic 'circuit boards' are fabricated and used to integrate microfluidic components into hybrid systems. A multi-level laminating mixer and a manifold with multiple pressure sensors are presented as application examples. To interface the microfluidic system to the macroscopic world, three types of DRIE-fabricated, tight-fitting fluidic couplers for standard capillary tubes are described. One type of coupler is designed for minimal dead space, while another type reduces the risk of blocking capillaries with adhesive. A third design demonstrates for the first time a silicon/plastic coupler combining DRIE coupler technology with injection-molded press fittings. (C) 1999 Elsevier Science S.A. All rights reserved.