DEM-LBM simulation of multidimensional fractionation by size and density through deterministic lateral displacement at various Reynolds numbers

Abstract

Fractionation through Deterministic Lateral Displacement (DLD) is a promising microfluidic method, able to address several particle characteristics. The influence of particle density on the fractionation however appears to be negligible at low Stokes numbers. In the present study, we investigate the trajectories of neutrally and negatively buoyant particles in standard DLD channels at different Reynolds numbers through coupled DEM-LBM simulations. The results show that the influence of particle density increases with Reynolds number, which enables fractionation by size and density. To facilitate the further use of our study, the results are combined in a correlation describing the influence of row shift fraction, Reynolds number and particle density on the critical diameter. Additionally, we investigate the influence of the Reynolds number on periods of neutrally buoyant particles and show that they can be predicted by simple fluid simulations through the introduced concept of fluidic periodicity.