Flow-induced "waltzing" red blood cells: Microstructural reorganization and the corresponding rheological response

Chih-Tang Liao; An-Jun Liu; Yeng-Long Chen

doi:10.1126/sciadv.abq5248

Flow-induced "waltzing" red blood cells: Microstructural reorganization and the corresponding rheological response

Sci Adv. 2022 Nov 25;8(47):eabq5248. doi: 10.1126/sciadv.abq5248. Epub 2022 Nov 25.

Authors

Chih-Tang Liao^{1

2

3}, An-Jun Liu^{1

4

5}, Yeng-Long Chen^{1

6

7}

Affiliations

¹ Institute of Physics, Academia Sinica, Taipei 11529, Taiwan (R.O.C.).
² Department of Engineering and System Science, National Tsing Hua University, Hsinchu 30004, Taiwan (R.O.C.).
³ Nano Science and Technology Program, Taiwan International Graduate Program, Academia Sinica and National Tsing Hua University, Taipei 11529, Taiwan (R.O.C.).
⁴ Department of Physics, National Taiwan University, Taipei 10621, Taiwan (R.O.C.).
⁵ Department of Physics, University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA.
⁶ Department of Chemical Engineering, National Tsing Hua University, Hsinchu 30004, Taiwan (R.O.C.).
⁷ Physics Division, National Center for Theoretical Sciences, Taipei 10621, Taiwan (R.O.C.).

Abstract

We investigate flow-induced structural organization in a dilute suspension of tumbling red blood cells (RBCs) under confined shear flow. For small Reynolds (Re = 0.1) and capillary numbers (Ca), with fully coupled hydrodynamic interaction (HI) and without interparticle adhesion, we find that HI between the biconcave discoid particles prompts the formation of layered RBC chains and synchronized rotating RBC pairs, referred here as "waltzing doublets." As the volume fraction ϕ increases, more waltzing doublets appear in RBC files. Stronger shear stress disrupts structural arrangements at higher Ca. We find that the flow-induced organization of waltzing doublets changes how the suspension viscosity varies with ϕ qualitatively. The intrinsic viscosity is particularly sensitive to microstructural rearrangement, increasing (decreasing) with ϕ at low (high) Ca that correlates with the change in the fraction of doublets. We verified flow-induced collective motion with comparison to two-cell simulations in which the cell volume fraction is controlled by varying the domain volume.