What does 'self-repair' refer to in materials science?

Self-repair in materials science refers specifically to the ability of a material to partially or completely repair damage that it has sustained. This phenomenon is significant in the development of advanced materials that can maintain their integrity and functionality over time, reducing the need for replacements and repairs. Self-healing materials utilize various mechanisms, such as the incorporation of microcapsules containing healing agents, which can be activated upon damage, leading to the restoration of the material's properties.

This characteristic is highly sought after in many applications, including coatings, composites, and structural materials, where durability and longevity are crucial. In contrast, the other options do not pertain to the definition of self-repair in materials science; they instead relate to very different fields, such as psychology, nanotechnology, and biology, respectively.