Suspension of deformable particles in Newtonian and viscoelastic fluids in a microchannel

摘要

In this paper, we study a suspension of cells at a moderate volume fraction flowing in a microchannel filled with Newtonian or viscoelastic fluids and investigate the role of cell size, cell volume fraction, inertia, deformability, and fluid elasticity on the cell distribution. Our results suggest that the use of constant-viscosity viscoelastic fluid pushes the cells toward the channel centerline which can be used in microfluidic devices used for cell focusing such as cytometers. The cell-free layer increases which provides larger gap for separating rare cells in microfluidic devices. Furthermore, we show that the volumetric flow rate can be significantly enhanced with the addition of polymers in the suspending fluid. This effect enhances the processing speed which is of interest in designing microfluidic devices. This fundamental study can provide insight on the role of rheological properties of the fluid that can be tuned to control the motion of the cells for efficient design of microfluidic devices.