omputer simulation and theory of the diffusion- and ow-induced concentration dispersion in microfluidic evices and HPLC systems based on rectangular icrochannels

he dynamics of formation of solute peaks inmicrofluidic systems are investigated by comuter simulation. A finite-element numerical procedure is applied to analyze the diffusionnd flow-controlled concentration dispersion in a 40 m-high rectangular flow-through hannel. Two-dimensional concentration profiles are shown for channels with cross secions of large aspect ratio. The final shapes of the peaks are formed during a very short time eriod, ranging from a fewmilliseconds to about 1 s for low and high flow velocities, respecively. The observed standard half-width of the peaks is found to strictly follow a linear unction of t1/2 over the whole time range. The extrapolated long-term peak characteristics re in perfect agreement with theoretical predictions. For comparison, theoretical results n the concentration dispersion for solute peaks in open-channel liquid-chromatography , Published in Analytica Chimica Acta 633, issues 1-2, 175-181, 2008 which should be used for any reference to this work 1