Flow-induced microstructural rearrangement and rheological consequences for model red blood cell suspensions in microvessels

Flow-induced structural evolution of soft particle clusters in microflow is a key driver of non-Newtonian fluid response. We investigated how inter-particle attraction affect cluster and particle migration in microvessels, where the near wall particle depletion layers due to hydrodynamics significantly alters fluid viscosity. We found that strong particle aggregation correspond to structurally intact large clusters at low shear rates, resulting in large near wall depletion layer and low suspension viscosity. Shear-induced cluster break-up at moderate shear rates reduces the wall depletion layer, corresponding to viscosity increase akin to shear-thickening. At high shear rates, particle deformation and inter-particle ordering leads to shear-thinning.