Bioinspired electrospun fibrous materials for directional water transport

Directional water transport behavior of living creatures is an emerging class in natural biology. Biomimetic fibrous materials with wettability gradient have attracted increasing attention from scientists because of their potential applications in controllable water manipulation. The combination of surface chemistry and the hierarchically porous structure is crucial for the preparation of fibrous materials with wettability gradient. Among various manufacturing techniques, electrospinning has been proven to be a versatile method that can be used to design and prepare fibrous materials with specific chemical compositions and surface wettability. Here we first introduce the typical directional water transport behaviors and mechanisms of natural creatures with special wettability, including spider silk, cactus spine, desert beetle, and shorebird beak. Then, we systematically describe the state-of-the-art method for the preparation of electrospun fibrous materials with directional water transport behavior from the perspective of one-dimensional fibers, two-dimensional surfaces, and three-dimensional aggregates. Finally, the remaining challenges in the field of directional water transport are highlighted, and the future development trends are summarized.