Electric Field Mediated Instabilities of a Thin Viscoelastic-Porous Confined Bilayer*

The polymeric-porous media interfaces' instabilities directly impacts several contemporary applications, such as organ-on-a-chips, microplastic depositions, emulating biofluid flows through arteries, and the performance of electrochemical storage devices. We have considered a model prototype of the abovementioned systems to uncover the interfacial characteristics in the presence of an external electric field. A confined system of thin solid viscoelastic polymeric film and deformable porous layer under the application of an external electric field is explored with the help of General Linear Stability Analysis (GLSA). The modified Kelvin-Voigt-Darcy-Brinkman model is used to represent the polymer displacement through the porous media, whereas zero-frequency solid linear viscoelastic constitutive relation is used to represent the polymeric film. The theoretical analysis unveils two distinct pathways of instabilities, (i) critical mode and (ii) dominant mode. The simulation results revealed that increasing electric-field potential reduces the length scale of instability in the dominant mode, which leads to pattern miniaturization. However, the porous layer's presence significantly alters the instability's time scale. The self-organized mesoscale patterns developed at the porous media interface with tunable length and time scales over a large area can be exploited to fabricate high-efficiency miniaturised smart devices for energy storage and biomedical applications.