Analysis of electro-osmotic flow in a microchannel with undulated surfaces

Abstract

The electro-osmotic flow through a channel between two undulated surfaces induced by an external electric field is investigated. The gap of the channel is very small and comparable to the thickness of the electrical double layers. A lattice Boltzmann simulation is carried out on the model consisting of the Poisson equation for electrical potential, the Nernst--Planck equation for ion concentration, and the Navier--Stokes {\color{black}equations} for flows of the electrolyte solution. An analytical model that predicts the flow rate is also derived under the assumption that the channel width is very small compared with the characteristic length of the variation along the channel. The analytical results are compared with the numerical results obtained by using the lattice Boltzmann method. In the case of a constant surface charge density along the channel, the variation of the channel width reduces the electro-osmotic flow, and the flow rate is smaller than that of a straight channel. In the case of a surface charge density distributed in homogeneously, one-way flow occurs even under the restriction of a zero net surface charge along the channel.

arXiv comment10 pages, 7 figures

References in corpus (5)

• Nanofluidics, from bulk to interfaces
• Minimal entropic kinetic models for simulating hydrodynamics
• Discrete solution of the electrokinetic equations
• Molecular dynamics simulation of electrokinetic flow of an aqueous electrolyte solution in nanochannels
• Generic transport coefficients of a confined electrolyte solution

Cited by in corpus (2)

• Driving an electrolyte through a corrugated nanopore
• Molecular dynamics and continuum analyses of the electrokinetic zeta potential in nanostructured slit channels