Will the day come when cracks in buildings close up without external help and before they get to the stage where they cause damage to the component? This might appear utopia, but it already occurs in nature. When a person suffers a minor wound, the human body reacts to close the opening, sending the blood platelets needed to the affected area – and with no need in many cases for any external coagulant substance to be employed.
This reaction of nature to damage suffered was the starting point for the development of self-repairing polymer materials with the capacity of recovering a good part of the properties lost and with no or with minimal external help.
In the case of ceramics or metallic materials, progress is much slower, being limited to initial steps. There are currently two notable self-repairing technologies in polymer materials: adhesives and thermal encapsulation.