  Due to evergrowing importance of understanding flow of bio-fluids in
Lab-on-CD based systems, we investigate the flow behaviour of power-law fluids
in the rotating electroosmotic flow through a polyelectrolyte grafted (soft)
narrow channel. We use a in-house numerical code to solve the governing
transport equations for the velocities and flow rates in a rotating channel
subjected to an applied external electric field. We show the strong effect of
polyelectrolyte layer on the flow behaviour and find an increase in flow rate
as we increase the size of the polyelectrolyte layer. We also show that
rheology strongly influences the interplay of the Coriolis forces due to
rotation and electrical body force due to the applied electric field. We show
that the velocities are generally higher for shear thinning fluids as compared
to shear thickening fluids. We also show that presence of polymer brushes in
the polyelectrolyte layer creates a drag on the fluid which reduces velocities.
We also show that the flow rates are strongly altered by the effect of rotation
and that shear thickening fluids have lower flow rates than shear thinning
fluids. We believe that studying effect of fluid rheology becomes very
important for designing soft channel based Lab-on-CD systems driven by
electroosmotic forcing and dealing with rheologically complex bio-fluids such
as blood, saliva or mucus.
