From Condensation Frosting to Anti-Frosting*

Condensation frosting, where supercooled dew nucleates on a surface and subsequently freezes into ice, is how the foundational layer of frost forms on chilled surfaces.  For perfectly wetting surfaces, the supercooled condensate simply forms as a continuous film that freezes over all at once.  But for non-wetting surfaces, condensation frosting manifests itself as inter-droplet ice bridges that connect frozen droplets to neighboring liquid droplets in a chain reaction.  First, we present scaling laws that rationalize the dynamics of the inter-droplet ice bridging events.  Second, a universal scaling law is developed to capture the extent of a dry zone that stabilizes about the perimeter of an isolated frozen droplet in the absence of ice bridging.  Finally, a scaling law and numerical model are used to optimize a passive anti-frosting surface comprised of a dilute array of ice stripes promoting overlapping dry zones.