A modulator microfluid system with an integrated micromixer

Microsystems are gaining more and more interest in several technological areas. The complete integration of different basic elements like pumps, valves and reaction chambers is possible by the use of microtechnologies. In the field of micro analysis systems a mixing procedure of different solutions is often required. A static micromixer built up in silicon has been developed. The design and fabrication procedures of the micromixer allow the integration of other microcomponents like pumps, valves or sensors. The micromixer consists of two structures silicon wafers. The structured surfaces are bonded together by using a low temperature silicon direct bonding process. The structure of the mixer consists of several identical mixing elements. The size of one element is about 500 mu m x 500 mu m x 720 mu m. Each element consists of two or more microchannels for different liquids to be mixed. The arrangements of the microchannels in the elements lead to a mixing of the liquids. We found a homogeneous mixing after about 5 mixing elements for mixable liquids. Not mixable liquids will be emulsified 0after about 16-20 mixing elements.