Hydroactuated configuration alteration of fibrous dandelion pappi: toward self-controllable transport behavior

Stimuli-responsive materials, especially those inspired by natural organism, have been extensively studied because of their versatile applications. Here, this study demonstrates that the unique hydroactuated reversible configuration alternation of the dandelion pappus, featured by the responsive spatial closing and opening the umbrella-like pappus depending on the environmental humidity, is a determining factor that allows the pappus to regulate its transport behavior. It is proposed that the anisotropic hydroactuated swelling of tracheids, which are typically arranged with an oblique crossing orientation, helps to generate the directional stress on the pappus. By this strategy, the pappus control its transport behavior in response to the environmental moisture, which allows long-distance and effective seeds dispersal selectively to local sites for optimal reproduction. Inspired by this, this study develops a hydroresponsive fiber array by integrating the hydrogel, whose configuration can be altered reversibly between the opening and closing state depending on the environmental humidity. This study believes the research can offer inspirations for designing and developing adaptive devices by using fibers array, as smart aerocraft.