Deformability-Based Electrokinetic Particle Separation

Teng Zhou,Sang Joo,Feng-Chen Li,Benjamin Mauroy,Li-Hsien Yeh

doi:10.3390/mi7090170

Abstract

Deformability is an effective property that can be used in the separation of colloidal particles and cells. In this study, a microfluidic device is proposed and tested numerically for the sorting of deformable particles of various degrees. The separation process is numerically investigated by a direct numerical simulation of the fluid–particle–electric field interactions with an arbitrary Lagrangian–Eulerian finite-element method. The separation performance is investigated with the shear modulus of particles, the strength of the applied electric field, and the design of the contracted microfluidic devices as the main parameters. The results show that the particles with different shear moduli take different shapes and trajectories when passing through a microchannel contraction, enabling the separation of particles based on their difference in deformability.

Highlights

The separation of small particles is one of the most important steps in many chemical and biological analyses [1,2,3,4,5,6]
DEP is a phenomenon in which a force is exerted on a dielectric particle when it is subjected to a non-uniform electric field
Some microfluidic separation devices that use the deformability of the motioned object have been proposed and validated

Summary

Introduction

The separation of small particles is one of the most important steps in many chemical and biological analyses [1,2,3,4,5,6]. A number of physical or topological properties of cells or particles, including size, shape, and deformability, can be used for separation. Some microfluidic separation devices that use the deformability of the motioned object have been proposed and validated. They are based either on inertia [41], obstacles [42] or on the DLD method [19]. An electric potential is applied externally from inlet AB to grounded outlets IH and FE to an incompressible Newtonian fluid domain Ωf. Solid boundaries—including the channel wall (Гw) and particle surface (Гp)—are electrically insulating, yielding n·∇φ = 0 on Γw and Γp (5). Where σp, σf, and σE are, respectively, the toσtpa·nl ps=trσesf·snft+enσsEo·nrf on the particle surface, the hyd(1r2o)dynamic stress tensor, and the Maxwell stress tensoσrf,=re−sppI e+cμti(v∇eul+y.∇uT)

Method and

Results and Discussion

Effect of Shear Modulus