Washington:
Spiders sprayed with water containing carbon nanotubes and graphene flakes have produced fibres that are tougher than anything ever measured, scientists say.
Emiliano Lepore at the University of Trento in Italy found a way to incorporate carbon nanotubes and graphene into spider silk and increase its strength and toughness beyond anything that has been possible before.
The resulting material has properties such as fracture strength and toughness modulus higher than anything ever measured.
Researchers kept 15 Pholcidae spiders, collected from the Italian countryside, in controlled conditions in their lab.
They collected samples of dragline silk produced by these spiders as a reference.
The team then sprayed the spiders with water containing the nanotubes or flakes and then measured the mechanical properties of the silk that the spiders produced.
Testing showed that some of the silk with nanotubes in it was 3.5 times as strong as giant riverine orb spider silk, which is considered the strongest natural spider silk, according to 'phys.org'.
Giving spiders water that is infused with carbon nanotubes makes them weave silk stronger than any known fibre, researchers concluded.
It is unknown how the spiders incorporated carbon nanotubes and graphene flakes into their silk. The team used spectroscopic methods to show that the carbon-based materials are present in the fibre but are unable to show exactly how.
One possibility is that the silk becomes coated with these carbon-based materials after it is spun, 'MIT Technology Review' reported.
Lepore and colleagues do not rule this out but say it is unlikely because the resulting structure would not have the strength they measured.
Instead, the team said it is more likely that the spiders ingest the water along with the carbon-based materials and these are then incorporated into the fibre as it is spun.