Bioinspired and Microgel-Tackified Adhesive Hydrogel with Rapid Self-Healing and High Stretchability

Adhesive hydrogels with self-healing and stretchability are expected to be used in a variety of fields including electronic skin, wound dressings, and wearable devices. Here, a novel strategy is exhibited to enhance the adhesiveness of hydrogels by introducing positively charged microgel into the hydrogel matrix of polydopamine inspired by the natural mussel adhesive mechanism. The synthesized hydrogels exhibit good adhesion not only on various organic and inorganic surfaces (such as polythene, polytetrafluoroethylene, rubber, ceramics, glass, and copper) but also on many biological tissue surfaces (e.g., heart, liver, lung, kidney, and hogskin). Compared with hydrogels only containing catechol moieties, the adhesion strength of microgel-containing hydrogels increased 8 times on glass substrates. In addition, the adhesive hydrogel also exhibits rapid self-healing and good stretchability due to the noncovalent interaction between the microgel and the hydrogel matrix. On the whole, doping microgel in the construction of multifunctional hydrogels substantially improved their adhesive ability on many types of surfaces.