Hydrodynamic particle focusing design using fluid-particle interaction

Abstract

For passive sheathless particles focusing in microfluidics, the equilibrium positions of particles are typically controlled by micro channels with a V-shaped obstacle array (VOA). The design of the obstacles is mainly based on the distribution of flow streamlines without considering the existence of particles. We report an experimentally verified particle trajectory simulation using the arbitrary Lagrangian-Eulerian (ALE) fluid-particle interaction method. The particle trajectory which is strongly influenced by the interaction between the particle and channel wall is systematically analyzed. The numerical experiments show that the streamline is a good approximation of particle trajectory only when the particle locates on the center of the channel in depth. As the advantage of fluid-particle interaction method is achieved at a high computational cost and the streamline analysis is complex, a heuristic dimensionless design objective based on the Faxen's law is proposed to optimize the VOA devices. The optimized performance of particle focusing is verified via the experiments and ALE method.

AC dielectrophoretic deformable particle‐particle interactions and their relative motions

“…By integrating the Maxwell stress tensor, the DEP force is obtained, which is defined as the Maxwell stress tensor (MST) method. The ALE method is adopted in the developed numerical model to solve fluid‐particle interactions simultaneously .…”

A novel passive micromixer with modified asymmetric lateral wall structures

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Dielectrophoretic choking phenomenon of a deformable particle in a converging‐diverging microchannel

“…Precise control of the motion of small particles is one of the most essential pursuits of microfluidics, which has vast applications in chemical research and biomedical studies . Many advances have been made in topics associated with this goal, including dielectrophoresis , hydrophoresis , magnetophoresis , and inertial methods . Dielectrophoresis has drawn particular attention due to its preciseness and appropriateness for biological particles .…”