This paper was presented at the 2nd Micro and Nano Flows Conference (MNF2009), which was held at Brunel University, West London, UK. The conference was organised by Brunel University and supported by the Institution of Mechanical Engineers, IPEM, the Italian Union of Thermofluid dynamics, the Process Intensification Network, HEXAG - the Heat Exchange Action Group and the Institute of Mathematics and its Applications.Cross-stream migration of macromolecules transported in a fluid flow is typically encountered in microfluidic applications. This experimentally observed phenomenon leads to a decrease of the nearwall macromolecule concentration which can be detrimental in applications relying on a high intensity of polymer reactions in the near-wall zone, such as DNA-based bio-sensors. Despite a significant body of
experimental, theoretical and numerical research, there is no consensus regarding the nature of this phenomenon. In this paper a meta-modelling approach for macromolecule motion in the flow is presented. It is demonstrated that the hydrodynamic interaction resulting from the incorporation of Saffman lift force, together with Faxen correction to Stokes drag causes migration of DNA molecules towards the middle of a
pressure driven micro-flow, which is in agreement with experimental observations. The results suggest that the migration can occur due to macromolecule-flow rather than macromolecule-wall interaction.This work has been supported in part by the European Commission under the 6th Framework Program (Project: DINAMICS, NMP4-CT-2007-026804
