2019/12/02 by Asena Abay, Steffen M. Recktenwald, Abay, Asena +7
Engineering · Medicine · #Microfluidic and Bio-sensing Technologies #Blood properties and coagulation #Microfluidic and Capillary Electrophoresis Applications
paper · pdf · doi:10.48550/arxiv.1912.00631
Constrictions in blood vessels and microfluidic devices can dramatically\nchange the spatial distribution of passing cells or particles and are commonly\nused in biomedical cell sorting applications. However, the three-dimensional\nnature of cell focusing in the channel cross-section remains poorly\ninvestigated. Here, we explore the cross-sectional distribution of living and\nrigid red blood cells passing a constricted microfluidic channel by tracking\nindividual cells in multiple layers across the channel depth and across the\nchannel width. While cells are homogeneously distributed in the channel\ncross-section pre-contraction, we observe a strong geometry-induced focusing\ntowards the four channel faces post-contraction. The magnitude of this\ncross-sectional focusing effect increases with increasing Reynolds number for\nboth living and rigid red blood cells. We discuss how this non-uniform cell\ndistribution downstream of the contraction results in an apparent double-peaked\nvelocity profile in particle image velocimetry analysis and show that trapping\nof red blood cells in the recirculation zones of the abrupt construction\ndepends on cell deformability.\n