Thermophoretically induced flow field around a colloidal particle

Abstract

A colloidal particle suspended in a fluid solvent with a non-homogeneous temperature undergoes a thermophoretic force. This force may translate into a directed drift of the particle and a source-dipole-like flow field around it. Alternatively, if the colloid is fixed in space, the accompanying flow is long-ranged. In this work, we provide a first simulation study of the thermophoretic force-induced flow fields by a particle-based mesoscopic method. The simulation results are quantitatively consistent with theoretical predictions obtained by solving hydrodynamic equations. Based on these results, we propose a single-particle microfluidic pump without movable parts, in which the flow direction can be reversed. Furthermore, we quantify the long-range hydrodynamic attraction between two suspended particles near the boundary wall induced by the thermophoretic flow field. © 2013 The Royal Society of Chemistry.