Bioinspired Smart Materials for Directional Liquid Transport

Bioinspired materials capable of driving liquid in a directional manner have wide potential applications in many chemical engineering processes, such as heat transfer, separation, microfluidics, and so on. Numerous natural materials and systems such as spider silk, cactus, shorebirds, desert beetles, butterfly wing, and Nepenthes alata have been serving as a rich source of inspirations in the area. During the last decades, great efforts have been devoted to design bioinspired smart materials for directional liquid transport. In this review, we begin by introducing several natural materials and systems with surface structural features contributing for their directional liquid transport property, followed by the basic concepts and theories about surface wettability, droplet motion, and driving forces with different structural features. Then, we summarize some typical applications of such bioinspired smart materials in industrial processes and chemical engineering, particularly in heat transfer, separation, and microfluidic systems. At the end, future perspectives of such bioinspired smart materials for directional liquid transport are discussed.