Superrepellency of underwater hierarchical structures on Salvinia leaf

Significance Instability and collapse of the underwater slippery air mattress hinder its applications, after which the air mattress cannot be recovered even on superhydrophobic surfaces like lotus leaves. Beyond superhydrophobicity, we present the underwater superrepellent capacity of Salvinia leaves, which can efficiently and robustly recover the invalid slippery air mattress by trapping the replenished air to replace the water in the microstructures. The interconnected wedge-shaped grooves on the base are key to the recovery, which spontaneously transport the replenished air to the entire surface governed by a gas wicking effect. Using 3D printing technology, biomimetic artificial Salvinia surfaces are fabricated, which successfully achieves the recovery of the air mattress. This finding will greatly extend the underwater applications of water-repellant surfaces.