Stronger Than Steel: Michigan Builds 'Spider Silk' Industry
If you’re a fan of Marvel superheroes, you know the story.
Boy meets spider.
Spider bites boy.
Boy develops extraordinary powers.
Boy designs uber-cool spider suit.
Now, imagine a tough, protective suit worn by real-life heroes that actually comes from a spider.
Back in 2007, I took a trip up to Camp Grayling, the sprawling military post where the Michigan Army National Guard plays its war games. That was the day I met then-Master Sergeant Ron Raflik, who picked me up in a Humvee, looking every bit the professional soldier.
“I’m wearing full individual body armor and a Kevlar helmet,” Raflik told me. “It’s also referred to as our ‘battle rattle.’”
That incarnation of battle rattle protected countless American soldiers on the battlefield for years. Now, the military is looking to take its combat uniform to the next level.
The Army has recently inked a more than $1 million deal with Ann Arbor-based Kraig Biocraft Laboratories to develop an elastic yet durable fiber that can be woven into protective clothing.
The science is fairly new. But the source is very old.
“Silkworms produce silk. Spiders produce silk. They have different recipes; different designs,” says Kraig Labs Chief Operating Officer John Rice.
Rice is talking about the protein silkworms use to spin their cocoons and spiders their webs. Spiders produce a particularly tough material that can absorb a lot of energy and even deform without fracturing. Problem is, it’s hard to round up a lot of spiders in one place to harvest their silk. They tend to eat each other.
So Kraig Labs has stepped in to teach an old worm a new trick.
“We’ve taken that recipe from the spider, re-created that and created an enhanced silkworm; a genetically engineered silkworm that produces that spider’s design,” Rice explains.
“You’ve taught a silkworm how to act like a spider?” I ask.
“That’s exactly right.”
Spider silk is more elastic than Kevlar, the fibrous material found in the Army’s combat helmet since the 1980’s. Rice says his company’s product could also be used in body armor and even protective undergarments.
Kraig Labs isn’t the only Michigan entity working on synthetic silk.
At the Bioeconomy Institute, just off the main campus of Michigan State University, Chad Pastor shows me around. He’s the business development manager here. We’re watching a frothy liquid churning in a cylinder about the size of an espresso maker.
Inside this foggy broth is replicated spider DNA.
Still, I’m a little puzzled.
“Where are the stars of our show? Where are the spiders?” I inquire.
Frankly, I’m not sure I really want to know.
“They don’t exist,” Pastor reassures me. “The real stars of the show are the microbes that are making the products themselves.”
Pastor says yeast is mixed with genetic material in a fermentation chamber to make microbes that will eventually grow...and grow...and grow.
“So the same way you’d brew beer is the same way that they make these proteins,” he says. “And then you separate the proteins, purify them; then they extrude them and they spin them into threads to make fabrics.”
From here, the product is scaled up in a sequence of fermenters until it comes out as a dense liquid.
Then, it’s shipped to California-based Bolt Threads, where it’s woven into fiber.
Bolt Threads is collaborating in the clothing business with a British designer who knows something about spiders.
Sir Paul’s daughter, Stella McCartney, has designed a brilliant gold dress made from synthetic spider silk yarn.
Silk protein fabrication is still a developing science. But Kraig Labs COO John Rice says his company is leaning on experience the silk textile industry has built over centuries.
“We have 4,000 years of history, of process, of equipment, of manufacturing, of design, of labor that all know how to do this very, very well,” Rice says.
And here’s the bottom line. With the advent of gene sequencing, the cost of replicating spider DNA has dropped dramatically in the last 10 years. Rice says that’s clearing the way for more products to come to market.
That’s all there is to tell for now. This yarn has been spun.