Living creatures have an amazing ability to repair and re-grow damaged tissue, but synthetic man-made materials normally can't do the same thing. Researchers at the University of Illinois have developed a special type of plastic which can 'grow' new material and repair itself much like a living animal or plant.
To give plastic this ability, researchers gave their plastic animal-like qualities. Copying the way animals heal puncture wounds by sending blood to clot at the flesh break, the team gave their plastic embedded capillary passages to transport the repair materials to the site of the damage. Normally, if you try to fill a larger hole with a liquid, it will simply drip down to the ground due to gravity. To overcome this, the team had to develop a special two-component plastic which can gel almost immediately, then build up slowly until the damage is repaired.
Practical applications for this technology might include everything from self-healing car bumpers to structures that are difficult to actively repair, like underground pipes and spacecraft. The researchers also say that they see a future where any plastic can be continually repairing itself over its lifetime, extending its life by reducing the natural breakdown the plastics suffer from due to age. Check out the video below to see how the process works, and how bullet holes in plastic sheets can be filled in. At this stage, the repair materials are injected directly into the plastic, but eventually, the repair process can be entirely automated, with the materials embedded permanently into structure of the plastic itself.