The Model of Porous Media - Complete Description for Aggregation of Bead-Monolayers in Flat Microfluidic Chambers
M. Grumann, M. Dobmeier, P. Schippers, T. Brenner, R. Zengerle and J. Ducrée
IMTEK - University of Freiburg, DE
Keywords: bead aggregation, monolayer, microfluidics, porous media, 2-phase flow
In this paper we for the first time adopt the model of porous media to simulate the complete course of the formation of monolayers from bead suspensions in a flat microfluidic chamber. The chambers are flat enough to enforce monolayer formation and the beads are confined by geometrical constrictions which sieve the beads from a pressure-driven flow through the chamber. The aggregation pattern of the beads impacts the trajectory of subsequently incoming beads. By modelling the previously aggregated beads with zones of porous media, we can drastically reduce the degrees of freedom in a two-phase, multi-particle problem. This way, we are able to compute stationary hydrodynamic flow patterns in the chamber. In an iterative master routine, these stationary solutions are taken as initial conditions for the next step. At the end of each iteration step, the aggregation pattern is extended according to the points where the newly added beads have settled down.
Nanotech 2004 Conference Technical Program Abstract