Cell trapping in Y-junction microchannels: A numerical study of the bifurcation angle effect in inertial microfluidics

Abstract

The majority of microfluidic technologies for cell sorting and isolation involve bifurcating (e.g., Y- or T-shaped junction) microchannels to trap the cells of a specific type. However, the microfluidic trapping efficiency remains low, independently of whether the cells are separated by a passive or an active sorting method. Using a custom computational algorithm, we studied the migration of separated deformable cells in a Y-junction microchannel, with a bifurcation angle ranging from 30° to 180°. Single or two cells of initially spherical shape were considered under flow conditions corresponding to inertial microfluidics. Through the numerical simulation, we identified the effects of cell size, cytoplasmic viscoelasticity, cortical tension, flow rate, and bifurcation angle on the critical separation distance for cell trapping. The results of this study show that the trapping and isolation of blood cells, and circulating tumor cells in a Y-junction microchannel was most efficient and least dependent on the flow rate at the bifurcation angle of 120°. At this angle, the trapping efficiency for white blood cells and circulating tumor cells increased, respectively, by 46% and 43%, in comparison with the trapping efficiency at 60°. The efficiency to isolate invasive tumor cells from noninvasive ones increased by 32%. This numerical study provides important design criteria to optimize microfluidic technology for deformability-based cell sorting and isolation.

Improving viability of leukemia cells by tailoring shell fluid rheology in constricted microcapillary

“…Both encapsulating droplet and the encapsulated cell change in shape during their passage through the contraction and almost regain their shape downstream the channel. Three different types of leukemia cells in these simulations including, myeloid (HL60) cell line, lymphoid (Jurkat) and neutrophil are modeled as a homogeneous viscoelastic liquid droplet 16,24 . The solvent viscosity of the cell fluid represents the cytosol viscosity and the polymeric viscosity represents the cytoskeleton viscosity 24 .…”

“…Three different types of leukemia cells in these simulations including, myeloid (HL60) cell line, lymphoid (Jurkat) and neutrophil are modeled as a homogeneous viscoelastic liquid droplet 16,24 . The solvent viscosity of the cell fluid represents the cytosol viscosity and the polymeric viscosity represents the cytoskeleton viscosity 24 . Cells have two viscosities: solvent viscosity representing cytosol viscosity and polymeric viscosity representing cytoskeleton viscosity.…”

“…The cells and biocompatible fluids have been modeled as viscoelastic fluids. In these models, the cell, which resembles a viscoelastic liquid droplet, has a Newtonian component (cytosol) and a viscoelastic component (cytoskeleton) 16 , 24 , 31 . The liquid droplet model with a constant cortical tension has been previously used to model the cell 16 , 29 , 40 .…”

“…Therefore, we model the cell as a viscoelastic liquid droplet. In this model the cell viscosity has two components: solvent viscosity which represents cytosol viscosity and polymeric viscosity which represents cytoskeleton 24 . The viscoelasticity inside the cell is represented by a FENE-CR viscoelastic model (Finite Extendable Nonlinear Elastic-Chilcott and Rallison) 25 .…”

Silicon Y-bifurcated microchannels etched in 25 wt% TMAH water solution

“…These convex corners were stable during etching. As there the compensation that typically leaves residues is not required, our findings allow fabrication of good quality Y-bifurcated microchannels for microfluidics [29][30][31]. In Ref.…”