The slippy nature of wetting flows

The hydrodynamics of wetting involves a singularity of viscous stress, and its microscopic regularisation ultimately determines the speed at which contact lines move over a surface. In a recent paper, Luo & Gao ( J. Fluid Mech ., vol. 1019, 2025, A52) explore a new analytical solution, based on which they construct a model for ‘slippery wedge flow’. This lucid approach provides an accurate description of viscous wetting flows in the presence of slip, without the usual restriction to small contact angles, and offers a quantitative multiscale formalism for slippery contact lines.