Augmented surface adsorption characteristics by employing patterned microfluidic substrates in conjunction with transverse electric fields

Abstract

The present study aims to theoretically demonstrate that the net rate of surface adsorption in a combined pressure driven and electrokinetically operated microfluidic arrangement may be considerably augmented with the application of transverse electric fields across the patterned walls of the flow channel, within the constraints of realistic biochemical reactions at chosen surface sites. Based on an approximate fully developed velocity profile that utilises the generation of an additional favourable axial pressure gradient (obtained as a combined consequence of the transverse and axial fields as well as the surface patterning effects), solutions of the species conservation equation are obtained, consistent with a combined advection–diffusion transport and second order reaction kinetics occurring at surface sites located on the microchannel walls. Different combinations of the electric fields and pattern angles are investigated, so as to obtain a physical basis governing their optimal combinations that are likely to result in the fastest possible net adsorption rates, within the practicalities of the chosen configuration. Some important considerations on the practical realisability of the designed configuration are also discussed.