Extreme wettability and tunable adhesion: Biomimicking beyond nature?

In this critical review, we summarize the recent developments of extreme wettability in nature and biomimetic examples, and then we focus on surface wetting behavior beyond nature, which means surface wetting properties that cannot be found in nature. They are: switchable wettability between (super)hydrophobicity and (super)hydrophilicity, switchable water/oil droplet adhesion between superhydrophobic pinning states and superhydrophobic rolling states, superoleophobicity at the air-solid interface or even under vacuum, and self-healing (super)amphiphobicity at the air-solid interface.