<scp>3D</scp> Printing Hydrogel, Perovskite Technology, and Preparation and Application of Hydrogel Perovskite Composite Materials

ABSTRACT Flexible electronic materials have received extensive attention and have become a research hotspot in recent years. Three‐dimensional (3D) printing technology, with its advantages such as high precision and high efficiency, has become an important choice for manufacturing flexible electronic devices. Through 3D printing technology, flexible materials with complex structures can be manufactured, making them applicable to various fields. Hydrogel–perovskite materials have shown broad prospects in flexible optoelectronic devices and intelligent response systems by combining the flexibility and environmental responsiveness of hydrogels with the efficient photoelectric performance of perovskites. However, their development is confronted with poor interface compatibility, insufficient long‐term stability (and difficulties in large‐scale preparation), and so on. Current research focuses on the optimization of composite structures, dynamic self‐healing mechanisms, and the cross‐application of bioenergy. However, how to precisely regulate interfacial chemical bonding to balance flexibility and efficiency, suppress ion migration and toxicity risks, and develop multi‐scale in situ characterization techniques remains an unsolved problem. This paper reviews the research progress of 3D‐printed hydrogels and 3D‐printed perovskite materials technology in recent years, summarizes the preparation of hydrogel–perovskite composites and their applications in optoelectronic devices, sensors, and other fields, and looks forward to the future development of 3D‐printed hydrogel–perovskite composites. The aim is to provide insights for the future development and application of 3D‐printed hydrogel–perovskite composite technology.