Enhanced diffusion in soft-walled channels with a periodically varying curvature

TL;DR

This paper investigates how periodically varying curvature in a channel can enhance particle diffusion, counteracting the typical slowdown caused by energy barriers, and potentially restoring free diffusion in confined systems.

Contribution

It introduces a model showing that shape-changing channels with sinusoidal curvature can increase diffusion rates, revealing a novel mechanism for controlling particle transport.

Findings

Periodic curvature can enhance diffusion rates.

Shape variation can restore free diffusion.

Energy barriers may facilitate faster diffusion.

Abstract

In one-dimension, the diffusion of particles along a line is slowed by the addition of energy barriers. The same is true in two-dimensions, provided that the confining channel in which the particles move doesn't change shape. However, if the shape changes then this is no longer necessarily true; adding energy barriers can enhance the rate of diffusion, and even restore free diffusion. We explore these effects for a channel with a sinusoidally varying curvature.