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arXiv · 1407.5673

Giant enhancement of hydrodynamically enforced entropic trapping in thin channels

S. Martens·A. V. Straube·G. Schmid·L. Schimansky-Geier·P. Hänggi
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Abstract

Using our generalized Fick-Jacobs approach [Martens et al., PRL 110, 010601 (2013); Martens et al., Eur. Phys. J. Spec. Topics 222, 2453-2463 (2013)] and extensive Brownian dynamics simulations, we study particle transport through three-dimensional periodic channels of different height. Directed motion is caused by the interplay of constant bias acting along the channel axis and a pressure-driven flow. The tremendous change of the flow profile shape in channel direction with the channel height is reflected in a crucial dependence of the mean particle velocity and the effective diffusion coefficient on the channel height. In particular, we observe a giant suppression of the effective diffusivity in thin channels; four orders of magnitude compared to the bulk value.

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S. Martens, A. V. Straube, G. Schmid, L. Schimansky-Geier, P. Hänggi. 2014-07-21. Giant enhancement of hydrodynamically enforced entropic trapping in thin channels. https://doi.org/10.1140/epjst%2Fe2014-02321-9

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