Front Microrhelogy of the non-Newtonian behaviour of blood

We introduce a new framework to study the non-Newtonian behaviour of fluids at the microscale based on the analysis of front advancement. We apply this methodology to study the non-linear rheology of blood in microchannels. We carry out experiments in which the non-linear viscosity of blood samples is quantified at different haematocrits and ages. Under these conditions, blood exhibits a power-law dependence on the shear rate. In order to analyse our experimental data, we put forward a scaling theory which allows us to define an adhesion scaling number. By applying this scaling theory to samples of different ages, we are able to quantify how the characteristic adhesion energy varies as time progresses [1]. We also analyze numerically the rheology of dilute red blood cell suspensions in pressure driven flows at low Reynolds number in terms of the elasticity of the cells. We identify the relevant aspects of cell elasticity that contribute to the rheological response of blood [2]. We have related the viscosity of healthy, anemic and alpha-thalasemic blood samples with the bending rigidity of the erytrocyte membrane [3].

[1] C. Trejo-Soto et al. Soft Matter, 2017, 13, 3042
[2] G. R. Lazaro et al. Soft Matter, 2014, 10, 7195
[3] C. Trejo-Soto et al. Preprint, 2018