[Perspective] Moving superhydrophobic surfaces toward real-world applications
Superhydrophobic surfaces have received rapidly increasing research interest since the late 1990s because of their tremendous application potential in areas such as self-cleaning and anti-icing surfaces, drag reduction, and enhanced heat transfer (1–3). A surface is considered superhydrophobic if a water droplet beads up (with contact angles >150°), and moreover, if the droplet can slide away from the surface readily (i.e., it has small contact angle hysteresis). Two essential features are generally required for superhydrophobicity: a microor nanostructured surface texture and a nonpolar surface chemistry, to help trap a thin air layer that reduces attractive interactions between the solid surface and the liquid (4, 5). However, such surface textures are highly susceptible to mechanical wear, and abrasion may also alter surface chemistry. Both processes can lead to loss of liquid repellency, which makes mechanical durability a central concern for practical applications (6, 7). Identifying the most promising avenues to mechanically...