Corpus ID: 235732129

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

  title={Enhanced diffusion in soft-walled channels with a periodically varying curvature},
  author={Thomas H Gray and Claudio Castelnovo and Ee Hou Yong},
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. 

Figures from this paper


Diffusion past an entropy barrier
Diffusion in a tube or channel of varying cross section has been treated, by Fick and Jacobs, as one-dimensional diffusion past an entropy barrier determined by the tube cross-sectional area orExpand
Entropic transport in energetic potentials
We study the transport of point size particles in micro-sized two-dimensional periodic channels, exhibiting periodically varying cross-sections. The particles are subjected to a constant externalExpand
Effects of curved midline and varying width on the description of the effective diffusivity of Brownian particles.
Analytical expressions are derived for the position-dependent effective diffusivity for two-dimensional asymmetric varying-width channels, and for three-dimensional curved midline tubes, formed by straight walls, by means of the modified Fick-Jacobs equation. Expand
Entropic particle transport in periodic channels
The regime of validity of the Fick-Jacobs equation is analyzed by means of analytical estimates and the comparisons with numerical results for the full two-dimensional stochastic dynamics for the nonlinear mobility and the effective diffusion constant. Expand
Entropic transport: kinetics, scaling, and control mechanisms.
It is shown that transport in the presence of entropic barriers exhibits peculiar characteristics which makes it distinctly different from that occurring through energy barriers, and this interesting property can be utilized to effectively control transport through quasi-one-dimensional structures in which irregularities or tortuosity of the boundaries causeEntropic effects. Expand
Diffusion in a two-dimensional channel with curved midline and varying width: reduction to an effective one-dimensional description.
  • R. M. Bradley
  • Mathematics, Medicine
  • Physical review. E, Statistical, nonlinear, and soft matter physics
  • 2009
The derivation of the equation of motion is completely rigorous and is based on an asymptotic expansion in a small dimensionless parameter that characterizes the channel width and provides a rigorous proof of the validity of the latter equation. Expand
Transport of Brownian particles in a narrow, slowly varying serpentine channel.
It is obtained that the mobility in a solid-channel is smaller than that in a soft-channel, and an alternative definition of the effective width of a soft channel is discussed that leads to equal mobilities up to second order terms. Expand
Brownian pump induced by the phase difference between the potential and the entropic barrier
Abstract Transport of Brownian particles in a finite channel is investigated in the presence of a symmetric potential and an unbiased external force. It is found that the phase difference between theExpand
Entropic splitter for particle separation.
The entropic splitting effect shown could be controlled upon variation of the geometrical parameters of the channel and could be implemented in narrow channels and microfluidic devices. Expand
Current control in a two-dimensional channel with nonstraight midline and varying width.
  • Feng-guo Li, B. Ai
  • Physics, Medicine
  • Physical review. E, Statistical, nonlinear, and soft matter physics
  • 2013
Transport of overdamped Brownian particles in a two-dimensional channel with nonstraight midline and narrow varying width is investigated in the presence of an asymmetric unbiased external force and the analytical expression of the directed current is obtained. Expand