A self-healing polymer based on genetic code of squid ring teeth could possibly extend the life of medical implants and fibre-optic cables in the future.
In order to fix itself, all the polymer needs is a drop of water.
"There are other materials that are self-healing, but not with water," said Melik Demirel, professor of engineering science and mechanics at Penn State University.
Demirel’s team has described the new material in the latest issue of the journal Scientific Reports.
They studied ring teeth of squid collected around the world ranging from the Mediterranean, the Atlantic, Hawaii and Japan, and found that proteins with self-healing properties are ubiquitous.
However, they found the natural self-healing proteins are only found in low quantities.
In order not to deplete squid populations, the researchers created the proteins in bacteria. The resulting polymer can then either be moulded using heat or cast by solvent evaporation.
The two-part co-polymer consists of a soft amorphous segment and a more structured material containing strands of amino acids connected by hydrogen bonds to form a twisted and/or pleated sheet. While the amorphous segment provides the self-healing properties, the structured part gives the material its strength.
The researchers created a dog-bone shaped sample of the polymer and then cut it in half. Subsequently, they used warm water and a slight amount of pressure exerted by a metal tool to reunite the two halves. Strength tests showed that the material after healing was as strong as when originally created.
"If one of the fibre-optic cables under the ocean breaks, the only way to fix it is to replace it," said Demirel. "With this material, it would be possible to heal the cable and go on with operation, saving time and money.
"Maybe someday we could apply this approach to healing of wounds or other applications," he said. "It would be interesting in the long run to see if we could promote wound healing this way so that is where I'm going to focus now."