Singular Dynamics and Symmetry Breaking in Electroosmotic Soft Lubrication Over Viscoelastic Substrates

This study examines the soft lubrication flows driven by electroosmotic slip along a viscoelastic wall, focusing on whether substrate rheology fundamentally alters pressuregeneration mechanisms. In the thin electrical double layer limit, electroosmosis introduces a tangential slip that contributes additively to the boundary-driven flux. We show that coupling this flow to a Kelvin-Voigt-Winkler foundation reveals viscoelasticity as a singular perturbation. Unlike the instantaneous constraint of purely elastic models, viscoelasticity introduces a dynamical relaxation field that regularizes contact degeneracies and enables long-time states unreachable in the elastic limit. Most notably, we report symmetry breaking and spontaneous rotation under sustained actuation. We provide a small-β asymptotic theory yielding the scaling law Ω∞ = C βκU2 0, where the rotation rate is governed by the elastic pressure distribution. These findings demonstrate that even weak viscoelasticity can qualitatively transform the steady-state behavior of electro-hydrodynamic lubrication systems.