Depletion Layer and Viscosity of Blood in Microfluidic Flow

Chih-Tang Liao^1,2*, Yeng-Long Chen²

¹Engineering and System Science, National Tsing Hua University, Hsinchu, Taiwan
²Institute of Physics, Academia Sinica, Taipei, Taiwan

* Presenter:Chih-Tang Liao, email:luckychild137@gmail.com

In blood flow, many different kinds of large proteins in the blood plasma induce attraction between red blood cells (RBCs) that results in columnar aggregates known as rouleau. To understand how polymer additives affect the aggregate structure of RBCs and blood viscosity, several experiments have probed how polymer additives such as dextran or polyethylene oxide affect the microstructure of RBCs. A few studies have shown that the RBC aggregation size increases with the increase of the polymer concentration and reaches a maximum at higher polymer concentration. In this study, we use the lattice Boltzmann method coupled with a coarse-grained spring network model for RBCs to simulate aggregating RBCs in a rectangular microchannel under Poiseuille flow. The effect of polymer additives is modeled by an attractive potential. We investigate the cell free layer thickness, the aggregate size and distribution, as well as the suspension viscosity in various shear rates and different strength of the attraction interaction.

Keywords: red blood cell, lattice Boltzmann method, suspensions