We took the spider silk gene, and we moved it into a goat embryo. The only time the goat produces the protein is in the milk when the female is lactating. We milk them, we collect the protein, we purify that protein, and then we spin fibers. – Randy Lewis, professor
LOGAN — Researchers at Utah State University are producing a material they say is stronger than steel but elastic like a rubber band.
They are creating an artificial spider silk, and they are using goats to help mass-produce it.
“The idea is to produce the smallest fibers you can because, proportionally, they get stronger,” professor Randy Lewis said. “If they make it a tenth in diameter, it’ll be 10 (percent) to 15 percent stronger. If you put 10 of those together, it’ll be stronger than one of the original fibers that was much bigger.”
Researchers can spin a mile of spider silk in less than an afternoon.
Lewis says his army of researchers is now ready to start turning the material into prototypes.
“Things like very, very fine sutures, artificial ligaments, artificial tendons,” he said. “People are interested in composite materials to replace Kevlar or carbon fibers or add to those and make an entirely different kind of material.”
It’s all based on the silk from a golden orb spider. The idea goes back nearly 20 years, but Lewis says he’s never been interested in arachnids — just their silk.
“It’s a unique material,” he said. “There’s no other biological like it, nor is there man-made material.”
The most unusual aspect of the research may be that Lewis and his team use genetically engineered goats to produce the silk’s protein in their milk.
“We took the spider silk gene, and we moved it into a goat embryo,” he said. “The only time the goat produces the protein is in the milk when the female is lactating. We milk them, we collect the protein, we purify that protein, and then we spin fibers.”
Lewis said the goats are more cooperative than spiders, and they are just as healthy and normal as average goats. USU researchers are also producing the protein in bacteria, silkworms, “and we even have transgenic alfalfa that we just started working on,” Lewis said. The idea is that one of those sources will stick as the best one.
It's a developing science, and, Lewis says, that is what makes the process exciting.
"We really feel like every day we come in here, we find something new,” he said.
Lewis and his team looked to a popular scene in the movie "Spider-Man 2" to bolster their case. In the film, Spider-Man stops a train using his spider silk.
“We actually went through and sort of calculated how much silk he used, how thick it was,” Lewis said.
They looked at the weight and speed of the train, as well as the weight of the passengers inside the train, to determine whether the scene was probable.
“And the answer is, he definitely can stop the train,” he said.
There was only one plot hole Lewis found.
“He’d have had to eaten about 80 pounds of beef steak to produce that much silk,” he said.
Lewis says his team is working with several companies to turn the silk into products.
The U.S. Navy is also interested in the silk for its adhesive properties, as a sort of ultimate super glue.