Phys.org  June 22, 2022 If the nature of the surface is such that it repels liquid, the very act of replenishing the film by spraying liquid on the surface may create vulnerable dry spots due to droplet collisions with the film. The formation of a stable dry spot has only been studied in the inviscid case. An international team of researchers (Russia, Canada) examined the break-up of viscous films, and demonstrated the importance and role of the viscous dissipation in both film and droplet. They proposed a new model to predict the necessary droplet energy to create a dry spot. […]