Role of solutal free convection on interdiffusion in a horizontal microfluidic channel

We studied the role of solutal free convection on the transport of a buoyant solute at the microfluidic scales, 5--500 \textmu{}m, both for a two-dimensional slit and a three-dimensional microchannel. Our theoretical predictions using both asymptotic analytical solutions and accurate numerical resolutions describe the different solute transport regimes.