We report on the long-time spreading of a droplet on a partially wetting surface, identifying a universal regime where the droplet profile becomes self-similar.
In this regime the dynamics are governed by a balance between viscous dissipation and capillary forces, with the substrate's geometry providing a slow secondary modulation. The result clarifies a long-standing discussion in the wetting community and offers a clean test bed for the hydrodynamic boundary conditions used in lattice-Boltzmann simulations of soft matter.
The paper, co-authored with members of the group and external collaborators, has appeared in Physical Review Fluids. A preprint is available on arXiv.