Simulation of Highly Nonlinear Electrokinetics Using a Weak Formulation

G. Soni[1], T. Squires[2], and C. Meinhart[1]

[1]Department of Mechanical Engineering, University of California Santa Barbara, CA, USA
[2] Department of Chemical Engineering, University of California Santa Barbara, CA, USA
Published in 2008

We present a numerical model for simulating highly nonlinear electrokinetic phenomena, which occurs at high zeta potentials. In this model, the electric double layer is realized by solving a partial differential equation (PDE) on the double-layer-inducing surface. We also allow for a nonlinear surface capacitance, which relates the surface charge density to the zeta potential of the surface.

With our model, we have quantified the impact of surface conduction on the magnitude of induced-charge-electroosmotic slip velocity. We predict that surface conduction significantly reduces the slip velocity and thus needs to be accounted for in all high-voltage electroosmotic simulations.

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