Self‐healing functional surfaces

During the last decade extensive research has focused on designing functional surfaces, e.g., with self-cleaning, antibacterial, or antifouling properties, driven by the industrial demand on innovation and sustainability, and the academic interest in new functional materials. Such functionalities are strongly related with surface characteristics, namely chemical composition, physical properties, and topography. Surfaces are, however, dynamic and easily damaged resulting in reduced performance or immediate loss of the functionality. Damage is ubiquitous, hence incorporating self-healing mechanisms allows repairing the functionalities while maintaining a high performance with extended service lifetime. Polymeric surfaces are particularly relevant for functional materials, covering the large majority of devices that are currently used. However, due to their chemical nature, they are typically soft and vulnerable to damages. This report covers the most recent advances concerning self-healing functional surfaces. Low adherence polymeric surfaces are addressed. Further then recovering chemical composition only, additional challenges raised by the recovery of other surface features, such as roughness, porosity, or heterogeneity, are considered. The impact of inherent surface dynamics on the recovery of surface functionalities is discussed, the limitations are highlighted and alternatives are suggested. The recent progress on self-healing of reversible and responsive surfaces is addressed and future research directions for self-healing functional surfaces are anticipated.