Two-phase microfluid flow based on AC electric field and conductivity gradient

To explore control method of multiphase fluid path, experiments of two-phase fluid path driving were carried out, during which when applying AC electric signal on the electrodes subjected on the microchannel, the fluid with higher conductivity would occupy the microchannel, and when the signals disappeared, the fluid path restored. A 2D analytical geometry model of the experimental system was proposed to deduce the net charges and Coulomb force at the interface and to analyze the system itself. By the charge conversation equation, convection-diffusion equation and Navier-Stokes equation, a numerical analysis has been done and the results show that the control of two-phase microfluid path can be achieved efficiently based on the logical conductivity gradient and electric field, which provides a theory basis for the integrated functions on lab-on-a-chip system.