Continuous separation of microparticles based on optically induced dielectrophoresis

To achieve high-throughput and high-efficiency separation based on optically induced dielectrophoresis (ODEP), an ODEP-based transient numerical model containing microparticles is developed under alternating current (AC) electric field coupling with an open flow field. In this model, the MST method is employed to calculate the time-averaged AC DEP force and the fluid viscous resistance acting on the particle, the Arbitrary Lagrangian–Eulerian (ALE) method is used to numerically solve the strong coupling electric-fluid–solid mechanics, and the efficient and continuous separation of microparticles is achieved. The results show that the trajectories of particles with different conductivity are clearly differentiated due to two different DEP actions, which enables separation of particles, and its separation performance can be optimized by adjusting the key parameters, including bright area width, applied alternating current (AC) electric voltage and inlet flow velocity. This study explains the continuous separation mechanism of particles under the combined action of AC electric field and flow field, and provides theoretical support for the design of high-efficiency ODEP microparticles separation device.