Beautiful and exceptionally strong, spider webs help capture food and can make good cocoons, but spiders webs are lesser known for their application in electronics, fiber optics, and medical diagnostics.
Now, Nolwenn Huby, a physicist at the Rennes Institute of Physics, in France, found that spider web silks are good at transmitting laser light. Like optic fiber, which can transmit light and enable a wide range of functions such as transmitting television images to detecting tumors and other lesions in the body, spider silk can transmit light (and information) on an integrated computer chip. Dr. Huby and her colleagues presented the findings at the Optical Society of America's annual meeting Oct. 11, where they discuss some of their potential applications, like medical imaging. Because spider silks are no wider than a human hair, they can shed light on very tight areas of the body that now are out of a surgeon's reach. In addition, spider silk-based devices could be implanted in the body, and because the silks are biodegradable and non-toxic, they could transmit diagnostic information and then be absorbed by the body when finished.
While promising, spider silk still needs some chemical tweaking before it can be used on an industrial scale. Fiorenzo Omenetto, a biomedical engineer at Tufts University, has been working with silkworm silk for years. Silkworm and spider silks share many properties, like incredible strength, thin size, and optical transmission. But silkworm silk can be made on large, industrial levels, whereas spider silks, at least for now, depend entirely on the willingness of the spider. Omenetto is looking at the proteins that made up silkworm silk, in order to produce natural plastics that could be used in electronics. For example, he recently created a silk-based device that shoots a laser beam. This could be useful in diagnostics; as light waves pass through a blood sample, say, molecules in the blood would change the way the light travels, and this change could be detected by a sensor. A silk-based sensor and transmitter could make diagnostics on a tiny scale and be biodegraded after its work is done.
This research is the first known to look at the optical properties of spider silk. "When we first tested spider silk, we didn't know what to expect," Huby said. "We thought, 'why not try this as an optical fiber to propagate light?" Omenetto hopes that devices based on silk (spider or silkworm) may be available within a decade. "I like to think we threw a big stone in the pond. Hopefully, the waves will continue."