NASA-funded research has created a material that could self-heal in seconds. Two layers of solid polymer sandwich a gel that with an ingredient that solidifies on contact with air (i.e. when one or both of the outer layers is damaged). This differs from other approaches that rely on a mostly-liquid compound, or similar, slower techniques. The protective applications in space craft (like the ISS) are obvious, and could add a vital line of defense against dangerous debris. The ISS already has shields to protect it, but reactive armour in the event of damage would be even more reassuring. Back down here on earth, the same material could be used in cars, pips, containers and even phones (beyond scratches). Watch the material get shot and self-heal in the video below.