Self-healing materials are known to be an out of this world idea, and several have been developed that can fix small cuts and hairline fractures. Researchers at University of Illinois have invented a type of plastic that not only heals fractures, but can regenerate over large cracks and holes. This could be extremely useful not just in day-to-day life, for example a self-healing car bumper (which would be amazing), but in areas where repairs are particularly difficult, like space.
The team used a process called “vascular delivery”, a technology it has been developing for some years that is based on veins. Liquid materials circulated within the material perform various tasks. In this case, the liquid materials are two chemicals that flow into the gaps created by damage via parallel capillaries. These chemicals, inspired by the way blood coagulates in the open air, mix in the spaces/voids to form a gel, which hardens into a strong polymer. This restores the plastic’s structural integrity.
The technology has been tested on both thermoplastics and thermosets, and has been demonstrated to regenerate a hole created by a 9mm bullet. In the experiments performed by the researchers, the chemicals were fed into the plastic, but the team envisions material pre-filled with the chemicals that can self-regenerate as needed. This is the first time it has been shown that you can regenerate lost material in a structural polymer. I can definitely see this being used in many defense applications!