Italian and British researchers have created a unique kind of material, produced by spiders that were "fed" with miscrosopic flaked of graphene and CNTs.
The scientists fed "special" water to three species of spiders. Dispersed within it were microscopic flakes of graphene, or carbon nanotubes. When silk was subsequently gathered from the spiders, it was found that the graphene/nanotubes had been passed into the fibers. As a result, its tensile strength and toughness were much higher than that of regular spider silk.
"We found that the strongest silk the spiders spun had a fracture strength up to 5.4 gigapascals (GPa), and a toughness modulus up to 1,570 joules per gram (J/g)," say the researchers. "Normal spider silk, by comparison, has a fracture strength of around 1.5 GPa and a toughness modulus of around 150 J/g".
According to the team, this is the highest fiber toughness discovered to date, and a strength comparable to that of the strongest carbon fibers. "These are still early days, but our results are a proof of concept that paves the way to exploiting the naturally efficient spider spinning process to produce reinforced bionic silk fibers, thus further improving one of the most promising strong materials", the team states.