title: Dynamic drag force based on iterative density mapping: A new numerical tool for three-dimensional analysis of particle trajectories in a dielectrophoretic system.
abstract: Dielectrophoresis is a widely used means of manipulating suspended particles within microfluidic systems. In order to efficiently design such systems for a desired application, various numerical methods exist that enable particle trajectory plotting in two or three dimensions based on the interplay of hydrodynamic and dielectrophoretic forces. While various models are described in the literature, few are capable of modeling interactions between particles as well as their surrounding environment as these interactions are complex, multifaceted, and computationally expensive to the point of being prohibitive when considering a large number of particles. In this paper, we present a numerical model designed to enable spatial analysis of the physical effects exerted upon particles within microfluidic systems employing dielectrophoresis. The model presents a means of approximating the effects of the presence of large numbers of particles through dynamically adjusting hydrodynamic drag force based on particle density, thereby introducing a measure of emulated particle-particle and particle-liquid interactions. This model is referred to as "dynamic drag force based on iterative density mapping." The resultant numerical model is used to simulate and predict particle trajectory and velocity profiles within a microfluidic system incorporating curved dielectrophoretic microelectrodes. The simulated data are compared favorably with experimental data gathered using microparticle image velocimetry, and is contrasted against simulated data generated using traditional "effective moment Stokes-drag method," showing more accurate particle velocity profiles for areas of high particle density.
authors.affiliation: School of Electrical and Computer Engineering, RMIT University, Melbourne, VIC, Australia.|Institute for Optofluidics and Nanophotonics (IONAS), Karlsruhe University of Applied Sciences, Karlsruhe, Germany.
authors.forename: Markus
authors.initials: M
authors.lastname: Knoerzer
authors.affiliation: School of Electrical and Computer Engineering, RMIT University, Melbourne, VIC, Australia.
authors.forename: Crispin
authors.initials: C
authors.lastname: Szydzik
authors.affiliation: School of Electrical and Computer Engineering, RMIT University, Melbourne, VIC, Australia.
authors.forename: Francisco Javier
authors.initials: FJ
authors.lastname: Tovar-Lopez
authors.affiliation: School of Electrical and Computer Engineering, RMIT University, Melbourne, VIC, Australia.
authors.forename: Xinke
authors.initials: X
authors.lastname: Tang
authors.affiliation: School of Electrical and Computer Engineering, RMIT University, Melbourne, VIC, Australia.
authors.forename: Arnan
authors.initials: A
authors.lastname: Mitchell
authors.affiliation: School of Electrical and Computer Engineering, RMIT University, Melbourne, VIC, Australia.
authors.forename: Khashayar
authors.initials: K
authors.lastname: Khoshmanesh
mesh_terms: D003198:Computer Simulation; D004586:Electrophoresis / Q000379:methods*; D004867:Equipment Design; D057446:Hydrodynamics; D021621:Imaging, Three-Dimensional / Q000379:methods*; D046210:Microfluidic Analytical Techniques / Q000379:methods*; D008863:Microspheres; D008962:Models, Theoretical
keywords: Dielectrophoresis; Drag force; Microfluidics; Microparticle; Numerical simulation; μPIV