Technologies and Microstructures for (Bio)chemical Microsystems

Abstract

There is a strong correlation between microreactors and microsystems for chemical and biochemical analysis. Microreactors need to be closely coupled to analysers, whereas in micro analysis systems a microreactor is often an important element. An example of a device that can be considered both as microreactor and as analyser, a catalytic gas sensor is presented. In particular the role of porous silicon material for fabrication and as support for the catalyst is shown. A modular concept for fabrication of micro analysis systems is illustrated with some components. A new capacitive pressure/flow sensor is presented with low power operation and a detection limit of 6 nl/s. Microchannels play an essential role in many micro analysis systems. Simulations made using the Flow3D programme based on the incompressible Navier-Stokes equations, give guidelines for the construction of the flow channel and positioning of sensors whereas the effects of the channel geometry on the profile of the injected plug can be predicted. Finally, a number of different techniques is presented to produce closed microchannels in silicon. Particular attention is paid to techniques that enable the fabrication of electrically insulating microchannels, which are of particular interest for capillary electrophoresis (CE) applications