Torn clothing, long the bane of all humanity (with the exception of the early-'90s grunge scene), may soon no longer require the old standby of a needle and thread.
A team of researchers at Pennsylvania State University has developed a fabric coating that enables garments made of everything from wool to silk to effectively "heal" rips and tears when exposed to water. In a paper published in ACS Applied Materials & Interfaces, the team detailed how fixing large tears could be made as easy as placing a patch on top of the hole and adding water and pressure. This video demonstrates the technique:
“The coatings are thin, less than a micron, so they wouldn’t be noticed in everyday wear," shares Melik Demirel, a professor of engineering science and mechanics at Penn State. "Even thin, they increase the overall strength of the material. For the first time, we are making self-healing textiles."
What's remarkable about this self-healing coating is that it's derived from squid ring teeth (SRT). The tentacles of some squid have evolved to include suction cups that contain a ring of razor-sharp teeth. This allows them to easily latch onto and take down prey. Unlike other hard tissues, such as bones, which require the addition of minerals to function properly, squid ring teeth are made up entirely of proteins.
According to the Penn State researchers, this protein exhibits "an unusual and reversible transition from a solid to a rubber and can be thermally shaped into any 3D geometry."
Squid ring teeth are made from a unique protein that has ability to transition from a rubber to a solid. (Photo: University of California, Riverside)
By uncovering the genetic code for these proteins, the team was able to replicate them in the lab and start testing their usefulness for other applications. While self-fixing jeans may one day be the norm, don't throw out that needle and thread just yet. The more immediate applications being explored include self-healing suits that would protect users from chemical and biological agents, biomedical implants and more.
And because such biolpolymers are seen as environmentally superior alternatives to synthetic plastics, there's also great promise in their ability to reduce both waste and pollution.
“We envision SRT-based materials as artificial ligaments, scaffolds to grow bone and as sustainable materials for packaging, substituting for today’s products made with fossil fuels,” said Ali Miserez, a professor studying SRT-applications at the Nanyang Technological University in Singapore. “There is no shortage of ideas, though we are just beginning to work on these proteins.”