Front microrheology of the non-Newtonian behaviour of blood: scaling theory of erythrocyte aggregation by aging

Abstract

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. This theory yields a scaling behaviour of the viscosity expressed as a function of the adhesion capillary 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. This connection between microscopic and mesoscopic properties allows us to estimate quantitatively the change in the cell-cell adhesion energies as the sample ages.

Microrheometer for Biofluidic Analysis: Electronic Detection of the Fluid-Front Advancement

“…The viscosity of blood obtained at was 12.2 mPa·s for the sample at 50% Ht; 10.67 mPa·s for 42% Ht; and 8.81 mPa·s for 35% Ht. These results were consistent with results obtained by other authors [ 26 , 27 , 28 ]. This constitutes a necessary benchmark to, in the near future, compare and detect rheological anomalies associated with hematological diseases, since the shape and biomechanical properties of RBCs can be altered in several diseases related to hematological disorders [ 29 ].…”

“…The hematocrit selected for further comparison to a benchtop device was 42% Ht, consistent with the levels found in healthy adults. All the tests were performed at room temperature (25 °C) and, for the case of blood, within two days of extraction, to avoid cell damage from aging [ 28 ]. At the beginning of each experiment, the DI water was evaluated to guarantee that the setup was properly calibrated.…”

Microfluidics Approach to the Mechanical Properties of Red Blood Cell Membrane and Their Effect on Blood Rheology

“…However, the rise of microfluidics at the end of the 1990s brought new applications and innovation in this area. In recent years, a variety of microfluidics devices and methods have been developed with the objective of measuring the viscosity of blood plasma [124][125][126][127] and blood [128], using optical detection techniques [75,[129][130][131][132][133][134], pressure sensors [135,136] and electrical sensors [137][138][139]; see Figure 6. In a capillary, the viscosity of the fluid is measured by establishing the relation between the pressure difference exerted on the fluid and the flow velocity.…”

Fluid mechanics and rheology of the jumping spider body fluid

“…To analyze the physical properties of spider hemolymph under physiological conditions, we modified the experimental set-up used by Trejo-Soto et al 36 in order to allow measurements of small samples (2 mL) at much higher pressures and shear rates (Fig. 7).…”