Graphene sprayed on spider silk produced a material with significant strength - enough to catch an airplane dropping from the sky, according to researchers. Applications for such super-strong fibers are numerous, but there are also some challenges facing developers.
Researchers combined particles or nanotubes of graphene, and sprayed the liquid on to spiders. The arachnids soon began spinning silk covered with the revolutionary form of carbon. The modified silk was found to be 3.5 times as strong as that produced by the giant riverine orb spider, which manufactures the strongest spider silk in the world. This makes the material as tough as limpet teeth, the hardest substance known in the animal kingdom.
How the graphene becomes embedded in the spider silk remains a mystery. The arachnids may coat the threads with the carbon material in an effort to clean themselves off after they are sprayed, researchers suggest. However, that may not provide the strength seen in the experiment. Another possibility is that the arachnids somehow incorporate the man-made substance into their natural silk, vastly increasing the strength of the material.
"Spiders could spin graphene and nanotubes in the silk also as an efficient way of eliminating them from their organism ... This new reinforcing procedure could also be applied to other animals and plants, leading to a new class of bionic materials for ultimate applications," University of Trento, Italy, researchers reported in their study.
The new super-strong form of spider silk could be used in a new generation of fabrics, as well as in the development of new bionic materials, meshing artificial and biological substances.
Graphene, first developed in 2004, consists of layers of carbon atoms just one layer thick. A pile of 75 million of the sheets lying on top of each other would be just one inch thick. The substance possesses remarkable strength, and electrical properties that could result in a number of applications in materials science and electronics.
There are several challenges facing developers who wish to find new uses for the graphene-modified spider silk. For one, four of the 15 arachnids in the study died after being sprayed with the artificial material. Other spiders lived through the application of graphene to their bodies, but spun lower-quality silk than they did before researchers coated them with the carbon-based material. These results, while promising in some cases, suggests the technique is still far from being practical on an industrial level.
Future research could examine how other animals, such as silkworms, are affected by the application of graphene, carbon nanotubes, and other artificial materials.
The results of the study of graphene-modified spider silk were detailed in a scientific article by the authors.
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