Rigid-flexible hybrid surfaces for water-repelling and abrasion-resisting

Abstract

Droplets impacting solid superhydrophobic surfaces is appealing not only because of scientific interests but also for technological applications such as water-repelling. Recent studies have designed artificial surfaces in a rigid-flexible hybrid mode to combine asymmetric redistribution and structural oscillation water-repelling principles, resolving strict impacting positioning; however, this is limited by weak mechanical durability. Here we propose a rigid-flexible hybrid surface (RFS) design as a matrix of concave flexible trampolines barred by convex rigid stripes. Such a surface exhibits a 20.1% contact time reduction via the structural oscillation of flexible trampolines, and even to break through the theoretical inertial-capillary limit via the asymmetric redistribution induced by rigid stripes. Moreover, the surface is shown to retain the above water-repelling after 1,000 abrasion cycles against oilstones under a normal load as high as 0.2 N.mm(-1). This is the first demonstration of RFSs for synchronous waterproof and wearproof, approaching real-world applications of liquid-repelling.