Stimuli-Responsive Bioinspired Materials for Controllable Liquid Manipulation: Principles, Fabrication, and Applications

Many emerging interfacial technologies, such as self-cleaning surfaces, oil/water separation, water collection, and microfluidics, are essentially liquid manipulation processes. In this regard, micro-nanostructures of the living organisms are highly preferable, by virtue of the evolutionary pressure and the adaptation to the specific environments, to inspire the optimization of man-made interfaces. With the increasing demands of modern life, research, and industry, intelligent materials with stimuli-responsive liquid manipulation functions have gained substantial attention from interfacial scientists. This review introduces the recent progress in the development of stimuli-responsive liquid-manipulating materials with bioinspired structures and surface chemistry according to two classified manipulation modes: (i) smart manipulation of liquid wetting behaviors, including lyophobic/lyophilic and superlyophobic/superlyophilic, and (ii) smart manipulation of liquid motion behaviors, including coalescence, transportation, rolling/adhesion, and sliding/pinning. At the beginning of the presentation of each classification, the theoretical basis and the sources of inspiration are introduced comprehensively to ensure a better understanding. This review mainly focuses on the mechanisms, fabrication, and applications of the state-of-the-art works related to smart and biomimetic liquid-manipulating materials. Finally, conclusions and future prospects are provided, and the remaining problems and promising breakthroughs in fabricating large-scale, cost-effective, and efficient smart liquid-manipulating materials are outlined.