Continuous Directional Water Transport on Integrating Tapered Surfaces

Controllable directional transport of droplets is ubiquitous in nature and essential in many practical applications, which is based on disparity of physical structures and surface energy. Despite vast innovations in liquid transport strategies to generate liquid transport at a wide spectrum and various scales, the transport distance is limited due to the drawback of unwanted pinning of contact lines. Here, a continuous, directional, and long-range transport system of fog droplets on integrating tapered surface inspired by spider silk and butterfly wing is reported. A new phenomenon occurs at the joint of integrating tapered surface: liquid film switches periodically between convex-continuous and concave-intermittent, which promotes the rapid surface reconstruction and fog droplet collection. The transport dynamics of fog droplets and rapid surface reconstruction facilitate highly effective water harvesting task.