Controlling Directional Liquid Transfer over a Ratchet-like Surface with Oriented Open-Wedges

Directed transfer of liquids is widely used as an important mass transfer strategy in the nature biology, industry, agriculture, and medical fields. Based on the bionic concept, researchers have constructed various forms of surface structures to realize controlled transport of liquids. However, current methods for preparing surfaces with directional liquid transport often suffer from cumbersome preparation processes, complexity of the prepared structures, and high costs. In this paper, we prepared a topological structure surface capable of precisely controlling liquid transport by a facile method. By utilizing 3D printing technology, we designed and fabricated a wedge-shaped surface with a periodic tilting scale arrangement. We accomplished the precise regulation of liquid transport on the surface of the structure, which not only realized the bi-directional transport of liquid anisotropically to the uni-directional transport on the surface but also achieved the precise regulation of the distance and speed of liquid transport through adjusting the opening angle formed by the open-wedges. We expect that the as-prepared wedge-shaped surface will provide a facile and efficient strategy for directional liquid transport.