MANIPULATION AND FLOW OF BIOLOGICAL-FLUIDS IN STRAIGHT CHANNELS MICROMACHINED IN SILICON

Analysis of minute sample volumes is a major analytical challenge that requires an understanding of fluid flow in microstructures. Accordingly, flow dynamics of biological fluids and cell suspensions in straight glass-capped silicon microchannels (40 to 150 mu m wide, 20 and 40 mu m deep) were studied. We demonstrated that these microstructures are appropriate components for microfluidic analytical devices. Different fluids were easily manipulated in the microchannels, and measurements of flow rate as a function of pressure for whole human blood, serum, plasma, and cell suspensions revealed non-Newtonian behavior. By means of micromachined filters (5 mu m) located in channels, blood cells and microparticles were effectively separated from nanoliter-sized samples, clearly indicating the future role of microstructures for a variety of analytical purposes.