Related Experiment Video
Updated: Aug 13, 2026

The Diffusion of Passive Tracers in Laminar Shear Flow
Published on: May 1, 2018
Hydrodynamic dispersion in shallow microchannels: the effect of cross-sectional shape
Armand Ajdari1, Nathalie Bontoux, Howard A Stone
1Laboratoire de Physico-Chimie Théorique, UMR 7083 CNRS-ESPCI, 10 rue Vauquelin, F-75231 Paris France. armand@turner.pct.espci.fr
Abstract:
We highlight the fact that hydrodynamic dispersion in shallow microchannels is in most cases controlled by the width of the cross section rather than by the much thinner height of the channel. We identify the relevant time scales that separate the various regimes involved. Using the lubrication approximation, we provide simple formulas that permit a quantitative evaluation of dispersion for most shallow cross-sectional shapes in the "long-time" Taylor regime, which is effectively diffusive. Because of its relevance for microfluidic systems, we also provide results for the short-time "ballistic regime" (for specific initial conditions). The special cases of parabolic and quasi-rectangular shapes are considered due to their frequent use in microsystems.
More Related Videos
10:55Procedure for the Development of Multi-depth Circular Cross-sectional Endothelialized Microchannels-on-a-chip
Published on: October 21, 2013
09:56Adapting Taylor Dispersion to Measure the Dispersion Coefficient of Electrolyte Solutions via an Accessible Microfluidic Setup
Published on: October 7, 2025
Related Concept Videos
Uniform Depth Channel Flow
Steady, Laminar Flow in Circular Tubes
Energy Considerations in Open Channel Flow
Steady, Laminar Flow Between Parallel Plates
Uniform Depth Channel Flow: Problem Solving
Rapidly Varying Flow