A bio-inspired flexible fiber array with an open radial geometry for highly efficient liquid transfer

Generally, highly efficient liquid transfer is difficult to achieve in open fibrous systems, as compared with traditional closed systems, because capillary coalescence frequently occurs when fiber arrays interact with a liquid. Dandelion pappi, which are flexible fiber arrays with open radial geometries, exhibit the unique ability to capture and hold large amounts of water steadily. Drawing inspirations from this natural system, we developed an artificial flexible glass fiber array with a radial geometry that is capable of holding large volumes of liquid and controllably transferring the liquid onto a substrate. The highly efficient liquid transfer of the open fibrous array can be attributed to the synergistic effects of the flexibility of fibers that radially arranged with a big open angle that enables a distinct elastic deformation of the fibers and the consequent formation of a large space within the fiber array for liquid storage, and the highly adhesive property of fibers that helps the pining of three-phase contact line on the fibers. This unique open system may provide a novel strategy for highly efficient and controllable liquid transfer.