Spiders and Squid Could Help Solve Our Global Plastic Problem
As issues with mainstream plastic get more public attention, scientists turn to animals to innovate improvements and potential replacements.
Traditional plastics are an environmental double whammy in that they have the potential to do harm at both the start and end of their lifecycles. | Photo credit: Pixabay
Plastic has infiltrated oceans, soils, and entire ecosystems around the globe—in part because 40 percent of plastics are currently produced for single-use packaging only. Yesterday, New York State lawmakers signed a budget instituting a statewide ban on most types of single-use plastic bags, a decision that may reflect increased awareness of the effects non-biodegradable products like plastic have on the natural world.
“These bags have blighted our environment and clogged our waterways,” said New York State Governor Andrew Cuomo in a statement released Thursday afternoon.
Traditional plastics are an environmental double whammy in that they have the potential to do harm at both the start and end of their lifecycles. Mainstream varieties like polyethylene terephthalate (PET), used to manufacture common products like plastic bottles, are derived from non-renewable fossil fuels like petroleum and natural gas. Moreover, synthetic plastics are designed to be durable and can take up to hundreds of years to decompose.
All stages of plastic’s life cycle, then, are fair game in scientists’ attempts to minimize damage.
“We’re seeing this momentum right now in Western societies to change—on a fundamental level—how we're using plastics,” says Martin Wagner, an ecotoxicologist at Norwegian University of Science and Technology.
Engineering alternatives
Some experts are looking to nature itself for inspiration. Take, for example, a spider’s silk web. Melik Demirel, a materials science engineer at Penn State University, has used proteins from spider silk to develop natural fibers that could replace synthetic plastic fibers like nylon and polyester. Demirel says spider silk proteins are obvious candidates because spider silk is known for its remarkable strength.
But recently, Demirel has found new bio-inspiration. He’s working with the rings of powerful “teeth” that line squid tentacles’ suction cups. Used to grasp their prey, squid ring teeth proteins share properties with spider silk proteins—so Demirel produced those proteins in the lab to develop a strong, degradable new fiber. If his team can scale up the material’s production, it might be able to replace the plastic coating on many synthetic textiles. That’s important because, when put in the washing machine, modern plastics-based clothing can release microplastics into water systems.
Some scientists are using proteins from the teeth of squid tentacles to develop a strong, degradable new fiber. | Photo credit: Hans Hillewaert / Wikimedia Commons (CC BY-SA 4.0)
Meanwhile, Geoffrey Coates, a chemical biologist at Cornell University, and his team are exploring ways to create plastic out of carbon dioxide. The gas appealed to Coates as a starting material because it’s commercially available and because industries that release carbon dioxide into the atmosphere could potentially capture the gas and use it to make plastic.
“You'd have to make a lot of plastic to make a dent in the amount of carbon dioxide that we add to the atmosphere,” Coates says. “But there's not going to be one solution to carbon dioxide capture. So anything you can do is certainly a good thing.”
The most commercially successful bioplastic thus far—a biodegradable plastic made from renewable resources—is made with corn. Called polylactic acid (PLA), it’s not yet strong enough to be practical and remains energy-intensive to produce due to its reliance on agriculture. But researchers like Marc Hillmyer, director of the Center for Sustainable Polymers at the University of Minnesota, haven’t given up hope, and continue to search for the key to making PLA tougher.
Some plastics are here to stay
Unlike single-use plastic bags, some plastic items are unlikely to be banned or replaced anytime soon. Many are even beneficial to ecosystems and human health. Margaret Sobkowicz Kline, a plastics engineer at the University of Massachusetts, Lowell, points to the biomedical and food security sectors, which rely on plastic packaging for sanitation and protection purposes. “I think it's important the public realizes we're not going to completely get away from plastics altogether,” Sobkowicz Kline says. “And I don't think we would want to.”
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Researchers are also looking for ways to better reuse and recycle these materials. Current plastic recycling often results in what is called “downcycling” because the second-generation product is of a lower quality. Researchers like Hillmyer and Richard Gross, a synthetic chemist at Rensselaer Polytechnic Institute, are exploring ways to break down used plastic into its original, high-value starting material for optimal reuse. They are also testing ways to make different plastics more compatible so they require less sorting and can be recycled more efficiently.
“We want to have the materials that we know and love,” Gross says. “But not have things that pollute our planet. So we're really interested in the end of life.”
The road ahead
With these innovations on the horizon, it might seem like better materials could hit the market any day now. But it remains challenging to develop materials that are strong, useful, and biodegradable. One barrier is cost: These new products are currently more expensive to produce—especially at the scales needed to make a dent in the plastics industry.
“There has to be a desire or a push to take on the expenses that are required to move these new products up the chain,” Gross says.
In 2015, around 322 million tons of plastic were produced worldwide. Shifting gears in an industry this massive is no small task. “Plastics are so entangled with our society,” Wagner says. “They are connected to all aspects of our lives and all aspects of the environment.”
Editor's Notes
As issues with mainstream plastic get more public attention, scientists turn to animals to innovate improvements and potential replacements.
Brittany FlahertyPosts By This Contributor