Evaporation-Driven Self-Assembly and Deposition Patterns of Protein Droplets: Mechanisms, Modulation, and Applications

Protein droplets exhibit complex self-assembly and deposition behaviors driven by evaporation, which has attracted increasing attention in recent years. Under evaporation, limited volume and locally concentrated protein solutions can undergo liquid–liquid phase separation (LLPS) and liquid–liquid crystalline phase separation (LLCPS), inducing the formation of concentrated droplets and anisotropic structures. The combined effects of interfacial tension and internal flow field induce a variety of deposition patterns on the substrate, providing great significance for the development of functional biomaterials. This paper reviews the physical processes experienced by protein/fibril droplets during evaporation, focusing on the formation mechanism of evaporation and their phase separation behaviors. At the same time, the review systematically summarized the key factors affecting the deposition patterns, and a variety of methods were introduced to pattern deposition, such as external electric field and micro-structured substrates. Furthermore, the potential applications of proteins/fibrils droplet deposition were discussed in multiple fields. This review aims to provide systematic theoretical support and experimental reference for understanding and controlling the deposition behavior of proteins/fibrils droplets, and to promote their further application in functional materials and biomedical engineering.