Three-dimensional numerical simulation of vesicle dynamics in microscale shear flows

Flow behaviors of blood strongly depend on dynamics of red blood cells (RBCs) under flow. Due to the simplicity, vesicles have been extensively used as a model system to investigate RBC dynamics. Despite its significance in microfluidics, the effect of confinement (i.e., ratio of vesicle size to microchannel size) on vesicle dynamics has not been reported in three-dimensional (3D) modeling. In this study, we developed a 3D mathematical model and investigated the effect of confinement on the dynamics of oblate-shaped vesicles in microscale shear flows. Our results indicated that confinement has significant effect on the dynamics of vesicles, including tank-treading, swinging and tumbling. An increase of confinement can induce the transition of vesicle dynamics from tumbling to swinging. This study could be helpful to future studies on the flow of vesicle suspensions at microscale, e.g., in vivo capillaries and in vitro microfluidics.