Liquid-solid composites with confined interface behaviors

Abstract In the evolving landscape of materials science, the expansion from traditional composite materials to liquid-solid composites has marked a significant shift. Composite materials, typically solid-state, have long been the cornerstone in many applications due to their structural stability and mechanical properties. However, the emergence of liquid-solid composites has introduced a new paradigm, leveraging the dynamic composite interfaces and fluidic nature of liquids. Recent years have witnessed the rapid development of liquid-solid composites, distinguishing themselves with their defect-free, molecularly smooth surfaces, and adaptive features. In this review, we introduce liquid-based confined interface materials, which represent a cutting-edge advancement, integrating confined liquids within solid frameworks at mesoscopic scales. Characterized by their confined competitive multiphase interfacial interactions, these materials offer practical functionalities like anti-fouling, multiphase flow control, and drag-reduction. We summarize the trendy development of the materials, and showcase important applications realized based on both controllable motions of the confined liquids and the solid frameworks. We also discuss their design and preparation and address the future challenges and outlooks, such as artificial intelligence in advancing functionalities.