Geometry-induced asymmetric diffusion

Schröter M, Shaw RS, Packard N, Swinney HL (2007)

Publication Language: English

Publication Status: Published

Publication Type: Journal article, Original article

Publication year: 2007


Publisher: National Academy of Sciences

Book Volume: 104

Pages Range: 9580-9584

Journal Issue: 23

DOI: 10.1073/pnas.0703280104


Past work has shown that ions can pass through a membrane more readily in one direction than the other. We demonstrate here in a model and an experiment that for a mixture of small and large particles such asymmetric diffusion can arise solely from an asymmetry in the geometry of the pores of the membrane. Our deterministic simulation considers a two-dimensional gas of elastic disks of two sizes diffusing through a membrane, and our laboratory experiment examines the diffusion of glass beads of two sizes through a metal membrane. In both experiment and simulation, the membrane is permeable only to the smaller particles, and the asymmetric pores lead to an asymmetry in the diffusion rates of these particles. The presence of even a small percentage of large particles can clog a membrane, preventing passage of the small particles in one direction while permitting free flow of the small particles in the other direction. The purely geometric kinetic constraints may play a role in common biological contexts such as membrane ion channels. © 2007 by The National Academy of Sciences of the USA.

Authors with CRIS profile

Involved external institutions

How to cite


Schröter, M., Shaw, R.S., Packard, N., & Swinney, H.L. (2007). Geometry-induced asymmetric diffusion. Proceedings of the National Academy of Sciences of the United States of America, 104(23), 9580-9584.


Schröter, Matthias, et al. "Geometry-induced asymmetric diffusion." Proceedings of the National Academy of Sciences of the United States of America 104.23 (2007): 9580-9584.

BibTeX: Download