Electrokinetic Pumping Flow Model in a Microchannel with Squeezing Walls*

The nonlinear Poisson–Boltzmann equation coupled with lubrication theory are used to model the flow motion in a microchannel with squeezing walls. The analysis is also used to describe the distribution of the electric potential across the electric double layer. A microfluidic pumping flow model driven by electroosmosis phenomena is developed to analyze the flow behavior of aqueous electrolytes. The solution is obtained without the classical use of the Debye–Hückel linearization technique and has been kept general. The effects of Debye length, zeta potential, and electric field on the pressure distribution, velocity profiles, shear stress, potential distribution, and net flow rate are presented. The results have shown that the electrokinetic pumping phenomena can possibly be used to understand microscale flow transport in various physiological systems.