Controlling effective dispersion within a channel with flow and active walls

Abstract

Channels are fundamental building blocks from biophysics to soft robotics, often used to transport or separate solutes. As solute particles inevitably transverse between streamlines along the channel by molecular diffusion, the effective diffusion of the solute along the channel is enhanced - an effect known as Taylor dispersion. Here, we investigate how the Taylor dispersion effect can be suppressed or enhanced in different settings. Specifically, we study the impact of flow profile and active or pulsating channel walls on Taylor dispersion. We derive closed analytic expressions for the effective dispersion equation in all considered scenarios providing hands-on effective dispersion parameters for a multitude of applications. In particular, we find that active channel walls may lead to three regimes of dispersion: either dispersion decrease by entropic slow down at small Peclet number, or dispersion increase at large Peclet number dominated either by shuttle dispersion or by Taylor dispersion. This improves our understanding of solute transport e.g. in biological active systems such as blood flow and opens a number of possibilities to control solute transport in artificial systems such as soft robotics.

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Cited by in corpus (13)

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• Antiresonant driven systems for particle manipulation
• Dispersion control in pressure-driven flow through bowed rectangular microchannels
• Solute transport due to Periodic Loading in a Soft Porous Material
• Interactions enhance dispersion in fluctuating channels via emergent flows
• An electrokinetic route to giant augmentation in load bearing capacity of compliant microfluidic channels
• Transport of a passive scalar in wide channels with surface topography
• Viscosity's impact on nutrient uptake along the gut
• Enhanced molecular diffusion near a soft fluctuating membrane
• Les Houches Lectures on Flow Networks in Biology