Hydrogels are crosslinked polymer networks that are biocompatible, mechanically flexible, and soft. They can be found naturally in collagen and gelatin or designed synthetically to respond to physical or chemical changes in their environment. Their diverse functionalities have paved the way for a wide range of applications, including healthcare, environmental protection, and soft robotics.

In this cross-journal Collection between Communications Materials, Nature Communications, and Scientific Reports, we aim to bring together advances in the topic of multifunctional hydrogels covering materials synthesis, analytical studies, and their demonstrations in biomedical, environmental, engineering, and natural sciences applications.