Spiders, or at least caricatures of them, are out in full force this Halloween weekend. But next time you see the eight-legged creature carved into a pumpkin, or dropping from the ceiling of a haunted house, perhaps consider feeling more than just spooked. A little respect is also appropriate. Arachnids, as they're scientifically known, could soon help you stay safer, warmer and healthier.
"They're not here to scare us," said Cheryl Hayashi, professor and vice chair of biology at University of California, Riverside. "There is lots of stuff we can learn from them."
She and other scientists are discovering not only what spiders do and how they do it, but also how to mimic those unique capabilities in the development of new products and technologies, from gentler airbags and better bandages to biodegradable water bottles. And these are just a few examples of how the burgeoning field of biomimicry is benefitting the health of humans and the planet. By looking at nature — and all that life has refined and perfected in its 3.8 billion years on Earth — researchers are figuring out how to create color without chemical-based dyes, deter pests without pesticides, fend off bacteria without antibacterials that may drive antibiotic resistance, and make products that can be absorbed back into nature rather than spending hundreds of years in a landfill or a plastic garbage patch in the Pacific.
In fact, some of these spider-inspired technologies are nearly ready for prime time. In an October press release, The North Face and Japan-based partners, Spiber and Goldwin, announced development of the first "successfully-produced synthetic spider silk material." The material is incorporated into their Moon Parka which, they stated, is "headed for commercialization in 2016."
"Currently, most sports apparel is made from synthetic polymer materials (such as polyester, nylon, etc.) that require petroleum to produce, and production of these materials consumes massive amounts of energy and produces large amounts of greenhouse gases," noted the press release.
The biomimicry potential of spiders goes beyond their ability to spin strong, slender and sticky webs of silk that outperform manmade materials. Spiders can also walk on water. They can carry life-sustaining air with them as they dive underwater. And the short, compact hairs on a spider's surface naturally repel water.
"Spiders have been fine-tuning [their technology] over hundreds of millions of years," added Hayashi. "Now those properties are available for us to try to replicate."
Stronger than steel
Hayashi, an evolutionary biologist, has always been fascinated by spiders — their spun silk, in particular. Ounce for ounce, spider silk can be five times stronger than steel, and even stronger than the Kevlar used in bulletproof jackets. What's more, spider silk fibers can actually increase in strength as they get finer. And the stuff is also incredibly stretchy and tough. It's truly unlike any other material, manmade or natural, Hayashi and other experts emphasize.
Turns out, there's not just one standard spider silk. A single species of spider can make one or even multiple types of silk, she explained. And there are more than 40,000 species of spiders, spanning a large variety of environments. Some silks are stretchier; some are stronger.
"By looking at the diversity of silks," said Hayashi, "we can use those recipes as templates for new materials."
Her lab is characterizing the genes and proteins involved in spider silk's properties and production. Many types show "enormous potential" to help human and environmental health, she said. The silk could be incorporated into a medical implant that would be lightweight, durable and not elicit an immune response, for example. Or it could be used to create strong fishing nets that could biodegrade, and therefore not entangle whales and other marine life.
And it's not just the finished products that might benefit humans and our environment. The manufacturing of the products could be cleaner and more energy-efficient. Spiders are part of nature, so they spin silks at ambient pressure and temperature conditions, unlike a typical chemical factory that produces nylon out of petrochemicals at high temperatures, explained Hayashi.
Still, replicating a spider's mass production of silk is not easy. And that is perhaps the greatest roadblock to getting spider silk products onto store shelves or into hospitals. "It turns out to be quite challenging," she said. "And that's not surprising, since spiders have been at it a really long time. They've had a huge head start on how to do this economically."
Randy Lewis, an expert in spider silk at Utah State University, is making headway on that problem of cost-effectiveness and scalability. And the whole process, he added, is "pretty green."
A spider spins its silk fibers from a water-based solution. But because they are naturally "territorial and cannibalistic," he explained, spiders can't simply be farmed. So instead, to produce the silk proteins, experts have transferred a spider's silk-spinning genes into other organisms, such as silkworms, bacteria, alfalfa and goats. To then take those proteins and spin them into products, however, they'd previously resorted to a slow process involving harsh and expensive organic chemicals. Now, his team has figured out how to rapidly dissolve the proteins in a water-based solution by generating pressure and temperature in a sealed vial with short, repetitive bursts from a conventional microwave.
Lewis added that it may even be possible to use waste products from agriculture to, say, feed the silk-producing modified bacteria. "You could be converting waste into a real honest-to-goodness product," said Lewis.
His team is also looking beyond fibers at coatings, adhesives, gels and films, which could have uses in automobiles, environmental sensors and medical devices. "So far we have not found anything we can't glue together," said Lewis, noting they've tried Teflon, silicone and even skin.
Cost, of course, is also a challenge in the development of a novel technology such as spider silk. But Lewis expressed optimism. "We can drive the cost down," he said. "It will not be as cheap as the cheapest materials. It's just really cheap to make anything from petroleum products."
Again, silk's astonishing properties are not the only source of inspiration scientists are gleaning from spiders. The hairy surface of a spider's body is also yielding some water-repellent ideas that Lewis noted could prove "very, very useful."
Wolfgang Sigmund, a professor of materials science and engineering at the University of Florida, has been studying that layer of hair on a spider, which he said has special self-cleaning features that could be harnessed into products that may one day prevent corrosion, conserve water and package food without worry of leaching toxic chemicals.
While the leaves of some plants, such as the lotus, also naturally repel water and have provided another source of water-resistant biomimicry inspiration, Sigmund noted that spiders have at least one advantage over a plant: While the surface of foliage can't recover from damage, a spider's body hair regrows.
His team has built materials that successfully mimic this pattern. On its surface, water stays "perfectly spherical" and "doesn't stick," he said. Since first coming out with that finding in 2010, the team has worked on making the structures stronger and less brittle, and therefore ready for real-world applications. They now have samples that won't be damaged when touched or rubbed, while also refusing to get wet.
Among the products his group is developing is a water-repellent paint that doesn't require clean water to keep clean. "You can spray muddy water on the building, and that would still take the dirt off," said Sigmund. "And that can save water."
He expects his group to establish a start-up company or attract industry pick-up of their simulated spider skin in the near future. "We should see this introduced very soon for prototypes and, soon after, it should enter the market," he said.
Meanwhile, The North Face's Moon Parka will likely be entering the market within months, potentially ushering in this new generation of spider-mimicking products. "For the first time in history, we are harnessing the power of evolution in order to create high-performance, sustainable and exciting protein materials," explains a Goldwin video that describes the Moon Parka technology. "This has endless applications and unlimited potential."