Taylor dispersion of a solute in a microfluidic channel

The dispersion of a solute, traveling in a laminar-flow microfluidic channel, along the major axis of the channel is described by Taylor dispersion. It is shown that although diffusion of solute along the major axis is often neglected in constructing a governing transport equation, axial dispersion due to the laminar flow profile influences the distribution of solute in the channel. An expression for the effective Taylor dispersion coefficient due to the laminar velocity profile is derived and verified by comparing the predicted dispersion to results from a three-dimensional finite-element representation of the fluid dynamics and solute transport. Since the dispersion coefficient can be several orders of magnitude greater than the molecular diffusion coefficient, axial dispersion in microfluidic channels should not be casually neglected.

[1]  O. C. Zienkiewicz,et al.  The Finite Element Method: Basic Formulation and Linear Problems , 1987 .

[2]  G M Whitesides,et al.  Patterning cells and their environments using multiple laminar fluid flows in capillary networks. , 1999, Proceedings of the National Academy of Sciences of the United States of America.

[3]  S M Gruner,et al.  Compactness of the denatured state of a fast-folding protein measured by submillisecond small-angle x-ray scattering. , 1999, Proceedings of the National Academy of Sciences of the United States of America.

[4]  J. Z. Zhu,et al.  The finite element method , 1977 .

[5]  G. Taylor.  Dispersion of soluble matter in solvent flowing slowly through a tube , 1953, Proceedings of the Royal Society of London. Series A. Mathematical and Physical Sciences.

[6]  B. Finlayson,et al.  Quantitative analysis of molecular interaction in a microfluidic channel: the T-sensor. , 1999, Analytical chemistry.

[7]  Mwj Menno Prins,et al.  Fluid control in multichannel structures by electrocapillary pressure. , 2001, Science.

[8]  P. Yager,et al.  Microfluidic Diffusion-Based Separation and Detection , 1999, Science.