Functional materials with self-healing properties: a review

Self-healing materials (SHMs) have been a research hot topic in recent years owing to their greatly improved longevity and safety in practical applications. Recently, research on SHMs has gradually expanded from structural materials to functional materials. Functional materials with self-healing properties (FMSH) require simultaneous repairing not only of the mechanical properties but of the functionalities from damaged cracks or wounds. It is more challenging to introduce both self-healing properties and a particular functionality to materials owing to the difficulties of preparing the materials and their more complex healing mechanism. Herein, we summarize the recent progress that has been made in FMSH, put forward insights from the perspectives of material preparation and healing mechanisms and highlight future developments for FMSH.