Multiphase lattice Boltzmann modeling of dielectrophoresis fractionation of soft particles

Abstract

Dielectrophoresis-field flow fractionation (DEP-FFF) is a promising method of fractionating particles from a continuous flow and has considerable application potential in the fields of biomedical, chemical, and environmental engineering. Particle deformation is an important issue in DEP-FFF, having a critical influence on the fractionation accuracy and viability of bioparticles. However, this problem has been largely ignored in both theoretical and numerical investigations. In the present work, a hybrid lattice Boltzmann scheme is introduced to study the deformation of soft particles subjected to the coupled effects of hydrodynamics and electrokinetics in a DEP-FFF process. The interaction of the particles with the fluid medium is calculated using a multiphase lattice Boltzmann model. The dielectrophoretic effect on the flow is introduced through a DEP force, which is obtained from a finite-element solution of the electric field. The hybrid scheme avoids the need to solve a coupled multiphysics problem, making it very efficient. The proposed simulation framework is validated through a well-known model, and the particle deformation and its influence on DEP-based fractionation are discussed.