Scientists create plastic that can repair itself

A plastic that can repair itself has been invented by a scientist who claims it is the first man-made material capable of mending its own "wounds" in the same way as human skin.

A plastic that can repair itself has been invented by a scientist who claims it is the first man-made material capable of mending its own "wounds" in the same way as human skin.

The invention could have immense value for plastic products used in critical situations, from aircraft to artificial limbs. It promises to revolutionise the use of plastics in industry and the home.

Scott White, professor of aeronautical and astronautical engineering at the University of Illinois at Urbana-Champaign, said tests had demonstrated that the plastic polymer was capable of repairing itself with remarkable efficiency.

A study reported in the journal Nature this week shows that, when damaged, the plastic regained as much as 75 per cent of its original strength. In a product that would lead to longer life with less maintenance, Professor White said. "Once cracks have formed within typical polymeric materials, the integrity of the structure is significantly compromised. Often these cracks occur deep within the structure where detection is difficult and repair is virtually impossible."

Hundreds of tiny "microcapsules" containing healing fluid are built into the plastic. When stressed, the capsules break, releasing the fluid, which runs into any microscopic cracks that have formed, sealing them and preventing larger cracks from forming. The scientists said all crack-healing methods that had been invented to date relied on some form of manual intervention butthe new plastic did the job automatically.

Richard Wool, a materials scientist from the University of Delaware in New Jersey, hailed the invention of a material that could mend itself as the "stuff of fantasy".

He said the plastic invented by Professor White appeared to fulfil all the requirements of a self-repairing material: the self-repair mechanism did not affect overall performance, it sensed damage as it happened and it reacted to damage to initiate healing. Professor Wool said: "This is a formidable array of requirements, which is probably why Professor White et al are the first to claim success in meeting them. Their system is ingenious."