Switchable and reversible wetting properties

Abstract Controlling surface wettability is essential for various applications such as water harvesting, oil/water separation, and smart skin technologies. Inspired by natural surfaces like lotus leaves and springtails, superhydrophobic materials exhibit water contact angles (CA) > 150°, low sliding angles (SA < 10°), and minimal CA hysteresis. This state is typically achieved via surface structuring and low surface energy coatings, often governed by the Cassie–Baxter model. However, this metastable state can irreversibly transition to the Wenzel state under external energy. Reversible and switchable wettability is attainable by integrating stimuli‐responsive materials. This review categorizes different external stimuli capable of modulating wettability: mechanical deformation, temperature, plasma treatment, light (UV), electron input, magnetic fields, solvent interaction, gas exposure, pH sensitivity, counterion exchange, chemical reactions. These strategies offer tailored control over surface‐liquid interactions, enabling smart interfaces.