Surface textures suppress viscoelastic braking on soft substrates.

ABSTRACT: A gravity-driven droplet will rapidly flow down an inclined substrate, resisted only by stresses inside the liquid. If the substrate is compliant, with an elastic modulus G < 100 kPa, the droplet will markedly slow as a consequence of viscoelastic braking. This phenomenon arises due to deformations of the solid at the moving contact line, enhancing dissipation in the solid phase. Here, we pattern compliant surfaces with textures and probe their interaction with droplets. We show that the superhydrophobic Cassie state, where a droplet is supported atop air-immersed textures, is preserved on soft textured substrates. Confocal microscopy reveals that every texture in contact with the liquid is deformed by capillary stresses. This deformation is coupled to liquid pinning induced by the

SUBMITTER: Coux M 

PROVIDER: S-EPMC7768693 | biostudies-literature | 2020 Dec

REPOSITORIES: biostudies-literature