Rheology of human blood plasma: Viscoelastic versus Newtonian behavior

TL;DR

This study reveals that human blood plasma behaves as a Newtonian fluid in shear flow but exhibits viscoelastic properties in extensional flow, affecting blood flow dynamics and flow resistance.

Contribution

It demonstrates the viscoelastic behavior of blood plasma in extensional flow and its impact on microfluidic blood flow, highlighting the importance of considering viscoelasticity in blood flow studies.

Findings

Blood plasma is Newtonian in shear flow.

Blood plasma shows viscoelasticity in extensional flow.

Viscoelasticity influences flow resistance and stability.

Abstract

We investigate the rheological characteristics of human blood plasma in shear and elongational flows. While we can confirm a Newtonian behavior in shear flow within experimental resolution, we find a viscoelastic behavior of blood plasma in the pure extensional flow of a capillary break-up rheometer. The influence of the viscoelasticity of blood plasma on capillary blood flow is tested in a microfluidic device with a contraction-expansion geometry. Differential pressure measurements revealed that the plasma has a pronounced flow resistance compared to that of pure water. Supplementary measurements indicate that the viscoelasticity of the plasma might even lead to viscoelastic instabilities under certain conditions. Our findings show that the viscoelastic properties of plasma should not be ignored in future studies on blood flow.