Transient electro-osmotic flow in rotating soft microchannel

Abstract

Exploiting secondary velocities produced by Coriolis forces in Lab-on-CD systems is key to achieving better transport in pharmaceutical and biomedical applications. We explore the transient behavior of velocities in rotating microchannels aided by a grafted polyelectrolyte layer (a soft layer). We further obtain an analytical solution for governing differential equations of the rotational electro-osmotic flow by the eigenfunction expansion method. We check and benchmark the solution with an in-house finite volume numerical code and also with results in literature for situation after transience has completed. We explore and discuss the effect of channel rotation, electro-osmosis, and polyelectrolyte layer on the oscillatory transient behavior of the flow velocities. We show that the size of the polyelectrolyte layer grafted to the walls aids in better control of the flow velocities and oscillations. We believe that controlled transient oscillatory behavior of velocities can be greatly used in Lab-on-CD based systems to manage the mass and momentum transport.