Dynamic structural regulation and multifunctional integration of 3D printed soft matter via metal coordination strategies

Soft matter, owing to its structural tunability and multifunctionality, is advancing applications such as in flexible electronics, smart actuation, and biomedical engineering. However, the trade-off between rheological properties and printing resolution during 3D printing process limits the fabrication of complex structures and restricts further applications. To address this challenge, metal coordination strategies, with their adjustable and reversible interactions, provide an effective route to endow soft matter with both high printability and multifunctional properties. This review systematically summarizes the key roles of metal coordination in precursor design, structural regulation, and functional construction. It first clarifies the requirements of different 3D printing techniques regarding the rheological behaviors of precursors and the stability of polymer networks, and outlines coordination-based strategies for reliable and high-resolution printing. It then illustrates how metal coordination enables in situ multifunctional integration, including self-healing, stimuli-responsiveness, and electrical conductivity. Finally, from an application perspective, it discusses representative cases in biomedicine, soft robotics, and environmental monitoring, and looks ahead to future opportunities in multifunctional integration and intelligent manufacturing. Overall, this work provides a systematic guideline and innovative framework for constructing high-performance 3D-printed soft matter via metal coordination strategies.