Researchers at the Max Planck Institute of Microstructure Physics in Halle, Germany have found a way to strengthen spider webs by infusing them with metals like titanium, aluminum, and zinc. As New Scientist reports, the technique could be used to produce tough artificial tendons if one were to substitute collagen for spider silk.
Here's how the team—led by Seung-Mo Lee and Mato Knez—operated on spider webs:
[T]he team fired beams of ionised metal compounds at lengths of silk from the orb-weaving spider Araneus diatematus using a technology called atomic layer deposition (ALD). As well as coating each silk fibre in a fine metal oxide, some metal ions penetrated the fibre.They tried zinc, aluminium and titanium compounds, all of which improved the mechanical properties of the silk. "With all three metals, the fibres can hold three to four times as much weight," says Knez. The fibres also become stretchier, so that their toughness - the energy needed to break a strand - rises even more. "The work needed to break the fibre rises tenfold with titanium, ninefold with aluminium and fivefold with zinc," he says. The results are published in the journal Science (DOI: 10.1126/science.1168162).
The team believe that the metals are reacting with the spider silk's protein structure, forming strong covalently bonded cross-links between the amino acid polymers within the silk. Normally, these polymers are only linked by weaker hydrogen bonds.
Reportedly, Knez believes this technique "has more immediate potential for toughening other biomaterials such as collagen." Of course, more research is needed if we're going to implant people with titanium-infused artificial tendons. David Williams of the University of Liverpool told New Scientist, "If the metals are covalently bound to the protein structure, they may remain safely locked up"—but if not, the material might be poisonous.