Carpet cloth

1 million spiders make golden silk for a rare fabric

But to make a textile of significant size, the silk experts had to scale up their project considerably. “Fourteen thousand spiders produce about an ounce of silk,” Godley said, “and the textile weighs about 2.6 pounds. The numbers are crazy.”

Researchers have long been intrigued by the unique properties of spider silk, which is stronger than steel or kevlar but much more flexible, stretching up to 40 percent of its normal length without breaking. Unfortunately, spider silk is extremely difficult to mass produce: unlike silkworms, which are easy to breed in captivity, spiders have a habit of biting their heads when housed together.

To get as much silk as they needed, Godley and Peers began hiring dozens of spider handlers to collect the wild arachnids and carefully harness them to the silk-mining machine. “We had to find people willing to work with spiders,” Godley said, “because they bite”.

At the end of the project, Godley and Peers extracted the silk from over a million female golden spiders, which are abundant throughout Madagascar and known for the rich golden color of their silk. Because spiders only produce silk during the rainy season, workers collected all the spiders between October and June.

Then, 12 more people used hand-held machines to extract the silk and weave it into 96-filament yarn. After the spiders were milked, they were released back into the wild, where Godley said it took them about a week to regenerate their silk. “We can go back and terminate the same spiders,” he said. “It’s like the gift that never stops giving.”

Of course, spending four years to produce a single spider silk textile is not very practical for scientists trying to study the properties of spider silk or for companies wishing to make the fabric for it. use as biomedical scaffolding or as an alternative to Kevlar armor. Several groups have tried to insert spider genes into bacteria (or even cows and goats) to produce silk, but so far attempts have been only moderately successful.

One of the reasons it is so difficult to generate spider silk in the lab is that it is initially a liquid protein produced by a special gland located in the spider’s abdomen. Using their spinnerets, spiders apply physical force to rearrange the protein’s molecular structure and turn it into solid silk.

“When we talk about a spider spinning silk, we are talking about how the spider applies forces to produce a physical transformation from liquid to solid,” said spider silk expert Todd Blackledge of the ‘University of Akron, which was not involved in the creation of textiles. “Scientists just can’t replicate this as well as a spider does. Every year we get closer and closer to being able to mass-produce it, but we’re not there yet.”

For now, it looks like we’ll have to settle for some incredibly beautiful fabric, graciously provided by over a million spiders.

Images: 1) AMNH / R. Mickens 2) Nicholas Godley and Simon Peers

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