Multiphase measurement of blood flow in a microchannel

Abstract

Blood is a complex fluid comprising red blood cells (RBCs) suspended in a continuous medium. Recent studies have shown that the spatial concentration distributions of the RBCs have a considerable impact on their velocity distributions. By extending this analysis, we present the first multiphase experimental analysis of microscale blood flow to include local velocity and concentration distributions of both phases of the blood. Human blood is perfused though a PDMS microchannel comprising a sequentially bifurcating geometry with a 50×50μm cross-section. The flow rate and the proportion of flow entering the branches of the bifurcation are varied, and the effects on the velocity and concentration distributions of the RBCs and suspending medium are analysed. In addition, the influence of RBC aggregation is investigated. The relative velocity between the two phases of the blood is shown to be dependent to varying degrees on all of the independent parameters examined in this study. A mechanism for the observed trends based on collisions of RBCs with the channel walls in the bifurcation is proposed.