Liquid Adhesion Regulation on Bioinspired Slippery Surfaces: From Theory to Application

Regulation of liquid adhesion on functional surfaces has attracted increasing attention due to its significant implications for fundamental research in liquid manipulation and a wide array of applications. Inspired by the slippery peristomes of Nepenthes pitcher plants, the concept of slippery surfaces with regulatable liquid adhesion under external stimuli was proposed and demonstrated. This review concentrates on the advancements in liquid adhesion regulation on these bioinspired slippery surfaces. Initially, we provide a concise introduction to the basic theory and design criteria of stable slippery surfaces. Following this, we summarize the characterization methods and influence factors of liquid adhesion on these surfaces. We then categorize the smart regulation modes of liquid adhesion into four key aspects: modulating the lubricant's phase, thickness, structure, and the interactions between the lubricant and the repellent liquid. Additionally, we systematically emphasize multibehavioral liquid manipulation strategies, such as movement, merging, splitting, bouncing, and rotating, along with the emerging applications of slippery surfaces, including pipetting devices, fog collection, microreactors, biochips, and nanogenerators. Finally, we discuss the remaining challenges and future perspectives for regulating liquid adhesion and the potential applications of smart slippery surfaces.