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) [1, 2], multi-level fluidic Ñcircuit boards? are fabricated and used to integrate microfluidic components into a hybrid system. As application examples, we demonstrate a multi-level laminating mixer and a multi-level manifold with multiple pressure sensors. 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 the DRIE coupler technology with injection-molded press fittings.

 Jaeggi, D., Gray, B. L.,  Mourlas, N. J., van Drieënhuizen, B. P. , Williams,  K. R., Maluf, N. I. , and Kovacs, G. T. A., "Novel Interconnection Technologies for Integrated Microfluidic Systems," Proceedings of the Solid-State Sensor and Actuator Workshop, Hilton Head, South Carolina, June 8 - 11, 1998, pp. 112 - 115.