Molting Materials: Restoring Superhydrophobicity after Severe Damage via Snakeskin-like Shedding.

The nanostructures that are required to generate superhydrophobic surfaces are always sensitive to shear and are easily damaged, especially by scratching with sharp objects. As a result of this destruction, the water repellency will be lost. We introduce a novel approach to restoring the original surface properties after mechanical damage. In this approach, the damaged layer is shed like the skin of a snake. This is demonstrated with a three-layer stack as a proof-of-principle system: when the original, superhydrophobic surface layer is damaged, this leads to the dissolution of a sacrificial layer below it. Thus, the damaged layer is shed, a new unscathed surface is uncovered, and superhydrophobicity can easily be restored after a short washing.