Biomimetic research indicates that many phenomena regarding wettability in nature, such as the self-cleaning effect on a lotus leaf and cicada wing, the anisotropic dewetting behavior on a rice leaf, and striking superhydrophobic force provided by a water strider's leg, are all related to the unique micro- and nanostructures on the surfaces. It gives us much inspiration to realize special wettability on functional surfaces through the cooperation between the chemical composition and the surface micro- and nanostructures, which may bring great advantages in a wide variety of applications in daily life, industry, and agriculture. This Account reviews recent progress in these aspects.

From soaking wet to bone dry: The concept of reversible switching between superhydrophilicity and superhydrophobicity of a surface (see picture) exploits the thermally responsive wettability of poly(N‐isopropylacrylamide), and this property is enhanced by surface roughness.