Microfluidic design, fabrication, and experiments have developed rapidly, leading to lab-on-chip separation or fractionation. In this work, we design a continuous concentrator for macromolecular solutions. Our design relies on the analytical solutions for orientational diffusion under laminar pressure-driven slot flow through a microchannel [W. Stasiak and C. Cohen, “Dilute solutions of macromolecules in a rectilinear Poiseuille flow,” J. Chem. Phys. 78, 553 (1983)]. Using rigid dumbbell theory, we provide analytical solutions for the design of our microfluidic macromolecular hydrodynamic chromatography. We arrive at our design through the use of well-known confinement-driven composition profiles. Using a pair of razor-sharp blades, our design separates the slot flow into a symmetric core inner slot (concentrated) between two outer slots (diluted). We discover a minimum dimensionless blade leading edge separation for complete fractionation, and that this decreases with confinement and also decreases with dimensionless shear rate.
Macromolecular microfluidic concentrators
Note: This paper is part of the special topic, Celebration of Robert Byron Bird (1924-2020).
S. J. Coombs, K. Tontiwattanakul, A. J. Giacomin; Macromolecular microfluidic concentrators. Physics of Fluids 1 October 2022; 34 (10): 103115. https://doi.org/10.1063/5.0116830
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