Editorial: Bioinspired Functional Surfaces with Superwettability: From Fabrication to Applications

Surface wettability is a basic property of solid materials, which is mainly determined by both the surface chemical composition and physical morphology.Recently, the materials with superwettability have attracted increasing attention because of their rich practical applications, such as liquid resistance, self-cleaning, anti-icing, droplet manipulation, oil/water separation, fog harvest, microfluidics, gas collection, drag reduction, and cell engineering.Many animals and plants have evolved special surface wettability.Inspired by nature, various artificial surfaces with extreme wettabilities (such as superhydrophilicity, superhydrophobicity, superoleophilicity, superoleophobicity, superaerophilicity, superaerophobicity, and slippery property) have been developed until now.This Research Topic gives a collection of reviews and research articles on the fabrication and applications of the superwetting surfaces.This special issue contains five reviews and two original research articles.Yong et al. discuss and clarify the relationship between six kinds of superwettabilities to water, oil, and gas, respectively.Usually, a superhydrophilic surface also shows superoleophobic and superaerophobic properties in water.By contrast, a superhydrophobic surface also shows superoleophilic and superaerophilic properties underwater.The superwettability of a textured surface can convert between superhydrophobicity and superhydrophilicity by simple hydrophilic and hydrophobic treatment.Therefore, we can realize various superwettabilities (for example, superhydrophilic, superhydrophobic, underwater superoleophilic, underwater superoleophobic, underwater superaerophilic, and underwater superaerophobic properties) on a rough microstructure and reversibly switch surface wettability from one state to other states.Some smart materials can respond to external stimulation, which have been explored to achieve switchable wettability.Han et al. summarize the recent progress of the switchable wettability based on the stimulus-responsive materials.The wettability of those smart surfaces can reversibly switch through changing the surface chemistry or surface roughness upon external stimulation (such as thermal, light, electrical field, magnetic field, and mechanical motion).Liu et al. briefly introduce three laser patterning methods to achieve superhydrophobic surfaces.The laser can process various materials and make geometrical modifications on those substrates.As a result, superhydrophobicity is easily obtained on laser-processed surfaces.Graphene is growing to a star material in the past decade.Ma et al. review the recent advances in the fabrication of superwetting graphene surfaces by laser processing.The multi-functions of the superwetting graphene surfaces are also introduced.Regarding the application examples, the integration of superwetting micro or nanostructures can endow optical devices with anti-liquid and self-cleaning properties.Bian et al. prepare an underwater superoleophobic microlens array on an optical glass.The resultant oil-repellent