Ice-proof coating for big structures relies on a ‘beautiful demonstration of mechanics’

Phys.org  April 25, 2019
The problem with the strategy to lower adhesion strength strategy is that the larger the sheet of ice, the more force is required. Researchers at the University of Michigan developed new coating which lowers the interfacial toughness (LIT). Surfaces with low LIT encourage cracks to form between ice and the surface. And unlike breaking an ice sheet’s surface adhesion, which requires tearing the entire sheet free, a crack only breaks the surface free along its leading edge. Once that crack starts, it can quickly spread across the entire iced surface, regardless of its size. Mathematically they predicted the properties of a coating without the need to physically test each one. This enabled them to concoct a wide variety of combinations, each with a specifically tailored balance between interfacial toughness and adhesion strength. A variety of coatings were tested on large surfaces—a rigid aluminum sheet approximately 3 feet square, and a flexible aluminum piece approximately 1 inch wide and 3 feet long, to mimic a power line. On every surface, ice fell off immediately due to its own weight…read more. TECHNICAL ARTICLE