Flow and Drop Transport Along Liquid-Infused Surfaces

Abstract

Liquid-infused surfaces (LISs) are composite solid–liquid surfaces with remarkable features such as liquid repellency, self-healing, and the suppression of fouling. This review focuses on the fluid mechanics on LISs, that is, the interaction of surfaces with a flow field and the behavior of drops on such surfaces. LISs can be characterized by an effective slip length that is closely related to their drag reduction property, which makes them suitable for several applications, especially for turbulent flows. Drag reduction, however, is compromised by failure mechanisms such as the drainage of lubricant from surface textures. The flow field can also sculpt the lubricant layer in a coupled self-organization process. For drops, the lubricant reduces drop pinning and increases drop mobility, but also results in a wetting ridge and the associated concept of an apparent contact angle. Design of LIS wettability and topography can induce low-friction drop motion, and drops can dynamically shape the lubricant ridges and film thickness.