Hydrodynamics of electroosmotic flow in a microchannel with porous wall

Abstract

Microchannel with porous wall has various microfluidic applications including iontophoresis, diagnostic devices, etc. In order to have an efficient and better design of such devices, exact quantification of velocity field in the microchannel needs to be established. In the present study, an analytical solution of velocity field in a microchannel with porous wall was obtained for a Newtonian fluid in case of a combined electroosmotic and pressure driven flow using perturbation technique. The velocity profile was reduced to well known solutions for three asymptotic cases, namely, purely electroosmotic flow and purely pressure driven flow in an impervious conduit as well as pressure driven flow with permeable wall. The pressure drop profile along the channel length was also generated. Effects of operating parameters, i.e., wall suction velocity, electrolyte concentration and channel half height on velocity and pressure fields were also investigated.