The latest advances in technology often attempt to mimic the functions of organisms. But no example of biomimicry is as intriguing as a new self-healing plastic that works like our own blood cells, patching wounds with liquid that hardens.

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"Historically, when you look at self-healing materials, you're really filling up small cracks, small-scale damage in existing material," says Scott White, an engineer at the University of Illinois. He was the lead author of a report on their findings, published in the journal Science this week. "Here, we don't have any existing material. It's gone, and we have to regenerate that entire material system from the ground up."

In 2013, the World Economic Forum called self-healing materials one of the top 10 emerging technologies. There are self-healing batteries. And self-healing plastics are already in cell phones that can repair faint scratches on the surface. But until now, these had only been able to repair minor damage. The process White and his colleagues developed can actually regenerate new material where "catastrophic damage requires a regenerative-like approach." In animals, this happens when blood coagulates around a cut. In effect, these chemists and engineers needed to endow plastic with its own vascular system.

"Now, the fluids don't just bleed out of the hole anymore," White said. "They're actually retained in place, and we grow on top of them until we completely seal up the damage itself." In the study, paid for by the Air Force, they demonstrated that damage wider than three centimeters could be repaired.

So, for example, say you live in a seedy part of town, and you find a bullet hole in your bumper one morning. The hole represents plastic that has been lost — chipped away and fallen because of gravity. With this self-healing plastic, the researchers developed a system of gel "capillaries" that release sticky liquid into the hole and harden over time. By the afternoon, your bumper would be good as new.

The applications would be of obvious benefit to airlines or the space industry. Space debris can puncture spacecraft. Repairs are expensive and potentially dangerous. While expensive to mass produce, self-healing materials may be cost-effective in the long run, Mark Miodownik, of University College London, told the BBC. (He was not involved in the study.) "If we really are serious about going to Mars and back, we're going to need our spaceships to be able to heal themselves," he said.