Electroosmosis with Augmented Mixing in Rigid to Flexible Microchannels with Surface Patterns

We explore the salient features of electroosmotic flow inside patterned and deformable microchannels. A computational fluid dynamic simulator is developed to solve the coupled Poisson’s equation for electrolyte, Laplace equation for external electric field, and continuity and momentum equations for fluid flow, with appropriate boundary conditions. The simulations reveal existence of some exceptional flow profiles with the variations in normalized Debye length, dimensions, and locations of heterogeneities, strength of external field, and deformability of walls. The surface heterogeneities are found to facilitate the variation in ζ-potential, which in turn locally modulate the flow rate to cause intermixing of layers. The extent of mixing due to the deformability and heterogeneity of the walls have been analyzed to identify the conditions for augmented micromixing in laminar electroosmotic flows. The variations of current densities along the walls with surface patterns have been explored for the probable application in differentiating the ζ-potentials of biosurfaces.