Bioinspired multiphase composite gel materials: From controlled micro-phase separation to multiple functionalities

The bigger pictureLiquid-liquid phase separation is ubiquitous and significant in biology for the execution of task-specific physiological or biochemical functions. This phase of state evolution, along with the generation of functionalized interfaces and compartments, provides inspiration for creating synthetic soft matter with similar structures and multiple functionalities. In this review, we summarized the fabrication strategies of gel materials with micro-phase-separated structures and further elucidated the functional diversity. By exploring structure-functionality relationships, we hope that this review can provide insights into the rational design of micro-phase-separated gels and solve the bottleneck problems in homogeneous and highly solvated gel networks to achieve diversity functionalities in practical applications including biomedicine, soft driving, and electronic engineering.SummaryPhase separation in living organisms is essential for the execution of biological functions, for example, the formation of membrane-less organelles and the functionalization of extracellular matrix proteins. In synthetic soft matter, gels have similarities to biological tissues due to their wet/soft properties and good biocompatibility. However, conventional gels with homogeneous networks are mechanically intolerant and unstable in solvent, which restricts their applications in various fields. Inspired by protein phase transitions of cellular processes in organisms, micro-phase separation is introduced into gel networks and devolved a series of robust functionalities gel materials. In this review, the critical design criteria and fabrication strategies of gel materials with micro-phase separation are summarized. Then, the multiple functionalities of these materials are systemically reviewed, including surface engineering, mechanical properties, shape memory, and sensor properties. Furthermore, we explore the current challenges and prospects in bioinspired micro-phase-separated gel field.Graphical abstract