Can non-linear elasticity explain contact-line roughness at depinning?

Abstract

We examine whether cubic non-linearities, allowed by symmetry in the elastic energy of a contact line, may result in a different universality class at depinning. Standard linear elasticity predicts a roughness exponent zeta=1/3 (one loop), zeta=0.39 (numerics) while experiments give zeta of about 0.5. Within functional RG we find that a non-local KPZ-type term is generated at depinning and grows under coarse graining. A fixed point with zeta=0.45 (one loop) is identified, showing that large enough cubic terms increase the roughness. This fixed point is unstable, revealing a rough strong-coupling phase. Experimental study of contact angles theta near pi/2, where cubic terms vanish in the energy, is suggested.

4 pages

References in corpus (2)

• Width distribution of contact lines on a disordered substrate
• Functional renormalization group for anisotropic depinning and relation to branching processes

Cited by in corpus (24)

• Driven particle in a random landscape: disorder correlator, avalanche distribution and extreme value statistics of records
• Size distributions of shocks and static avalanches from the Functional Renormalization Group
• Drops on an inclined heterogeneous substrate: onset of sliding motion
• Rayleigh and depinning instabilities of forced liquid ridges on heterogeneous substrates
• Avalanche dynamics of elastic interfaces
• Short time relaxation of a driven elastic string in a random medium
• Cusps and shocks in the renormalized potential of glassy random manifolds: How Functional Renormalization Group and Replica Symmetry Breaking fit together
• Chaos and residual correlations in pinned disordered systems
• Creep of a fracture line in paper peeling
• Short-time domain-wall dynamics in the random-field Ising model with a driving field
• Roughness of moving elastic lines - crack and wetting fronts
• Experimental and theoretical investigation of angular dependence of the Casimir force between sinusoidally corrugated surfaces
• Roughness of tensile crack fronts in heterogenous materials
• Elasticity of a contact-line and avalanche-size distribution at depinning
• Exponent Inequalities in Dynamical Systems
• Dynamical Inequality in Growth Models
• Depinning in a two-layer model of plastic flow
• Experimental test of Sinai's model in DNA unzipping
• Glassy dynamics, aging and thermally activated avalanches in interface pinning at finite temperatures
• Large-scale Monte Carlo simulations for the depinning transition in Ising-type lattice models
• Long-range interactions in the avalanches of elastic interfaces
• Wetting and Minimal Surfaces
• On the Self-Affine Roughness of a Crack Front in Heterogeneous Media
• Nonsteady dynamics at the dynamic depinning transition in the two-dimensional Gaussian random-field Ising model