LAUSR

Abstract We study the streaming potential modulated autonomous illing dynamics of a viscoelastic fluid in a microfluidic channel . To describe the rheology of viscoelastic fluid, we consider a simplified Phan-Thien-Tanner (sPTT) model. Considering the electroviscous effect, along with the effects of surface tension force and viscous resistance, we derive a reduced-order model for obtaining the variations in the filling dynamics for different physical parameters of the system. We observe that a complex competition between the viscoelasticity and the electroviscous effect leads to the non-trivial behaviour in the temporal evolution of the filling dynamics. Moreover, our analysis unveils that an enhancement in the electroviscous effect due to increasing viscoelasticity of the fluid leads to a non-linear reduction in the filling length of the fluid in the channel. Consequently, the notion of having a higher filling length for the more elastic nature of the fluid is contradicted here due to the presence of the electroviscous effect. Finally, we establish a regime ( x ∼ t ) at a later stage of filling in the channel. We show that this regime is unique to the surface tension driven filling of viscoelastic fluids in a charged fluidic pathways under the influence of electroviscous effect.