The effect of AC electric field on the dynamics of a vesicle under shear flow in the small deformation regime

In this work, the dynamics of a vesicle subjected to simultaneous shear and uniform alternating current electric field is investigated. The coupled equation for vesicle orientation and shape evolution are derived theoretically and the resulting nonlinear equations are handled numerically to generate relevant phase diagrams that demonstrate the effect of electrical parameters on the different dynamic regimes such as tank-treading, trembling, and tumbling. It is found that while electric Mason number which represents the relative strength of the electrical forces to the shear forces, promotes tank-treading regime, the response itself is found to be sensitive to the applied frequency as well as the conductivity ratio. While higher outer conductivity promotes orientation along the flow axis, orientation along the field is favored when the inner conductivity is higher. Interestingly, in some cases, a coupling between electric field induced deformation and shear can result in the system admitting an intermediate tumbling regime while attaining the TT regime at high Mn. The results could enable designing better dielectrophoretic device.