Interfacial particle motion by dielectrophoretic force

Abstract

Direct numerical simulations of motion of an interfacial two-dimensional cylinder under the effect of the dielectrophoretic force in an electric field are conducted and the performance of the vertical force balance and the horizontal motion is investigated. The influence of important factors (contact angle, viscosity ratio, permittivity, particle density and radius) on the velocity is studied. Results show that different particle densities and viscosity ratios tend to change the magnitude of drag force and different contact angles, fluid medium permittivities, particle permittivities and particle radii tend to change the magnitude of dielectrophoretic force, which leads to influence the velocity of interfacial particle motion. This work innovatively applies the dielectrophoretic force to drive interfacial particle motion. We hope this work may provide an advanced method for efficient and contactless removal of particle contaminations at fluid interfaces by means of dielectrophoresis. Our study may provide a new efficient method for actively transporting and separating interfacial particles and pave the way to the research about the interaction of dielectric particles floating on fluid interfaces instead of suspending in fluid medium. The dielectrophoresis may contribute to the development of driving technology for microrobots attached to fluid interfaces.