Viscoelastic fluid flow in circular narrow confinements driven by periodic pressure and potential gradients

We present an in-depth analysis and analytical solution for AC hydrodynamic flow (driven by a timedependent pressure gradient and/or electric fields) of viscoelastic fluid through cylindrical micro-, nanochannels. Particularly, for this purpose we solve the linearized Poisson-Boltzmann equation together with the incompressible Cauchy’s momentum equation under no-slip boundary conditions. The resulting solutions allow us to predict the electrical current and solution flow rate. The results satisfy the Onsager reciprocal relation. The validity of these Onsager relations is important since it enables an analogy between fluidic networks in this flow configuration and electric circuits. They especially are of interest in micro- and nanofluidic energy conversion applications [1]. We furthermore found that AC electrical actuation leads to a stronger flow enhancement than AC pressure actuation. The findings advance our understanding of AC electrokinetic phenomena of viscoelastic fluids and provide insight in flow characteristics as well as can assist the design of devices for lab-on-chip applications.