Issue 20, 2021

Channel-length dependence of particle diffusivity in confinement


Understanding the diffusive behavior of particles and large molecules in channels is of fundamental importance in biological and synthetic systems, such as channel proteins, nanopores, and nanofluidics. Although theoretical and numerical modelings have suggested some solutions, these models have not been fully supported with direct experimental measurements. Here, we demonstrate that experimental diffusion coefficients of particles in finite open-ended channels are always higher than the prediction based on the conventional theoretical model of infinitely long channels. By combining microfluidic experiments, numerical simulations, and analytical modeling, we show that diffusion coefficients are dependent not only on the radius ratio but also on the channel length, the boundary conditions of the neighboring reservoirs, and the compressibility of the medium.

Graphical abstract: Channel-length dependence of particle diffusivity in confinement

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Article information

Article type
24 Feb 2021
31 Mar 2021
First published
06 Apr 2021
This article is Open Access
Creative Commons BY license

Soft Matter, 2021,17, 5131-5136

Channel-length dependence of particle diffusivity in confinement

S. Tottori, K. Misiunas, V. Tshitoyan and U. F. Keyser, Soft Matter, 2021, 17, 5131 DOI: 10.1039/D1SM00289A

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