Cotton fibers modified to glow under ultraviolet light. (Filipe Natalio)
It could be the biggest advance in cotton technology since Eli Whitney’s gin. Scientists have found a way to augment the fibers with useful new properties.
Seven or eight thousand years ago, humans figured out that the natural fibers cotton plants produce could be spun into strands and woven into fabric. During the Industrial Revolution and after, it became one of the world’s most valuable commodities—and helped drive the slave trade in the Americas and Europe.
Cotton is great. It's soft and light and durable enough. It’s pretty warm and dries pretty fast. But is that really all it can do for us? Filipe Natalio, a chemist at the Weizmann Institute of Science in Israel, thinks cotton can do better.
Natalio demonstrates a way to enhance cotton with new properties in a new paper in Science. He’s made fibers that glow and fibers that are magnetic.
His team of researchers in Israel, Germany, and Austria used sugar molecules to sneak new properties into cotton. Like a Trojan horse, Natalio says. They tested the method by tagging glucose with a fluorescent dye molecule that glows green when hit with the right kind of light.
They bathed cotton ovules—the part of the plant that makes the fibers—in the glucose. And just like flowers suck up dyed water in grade school experiments, the ovules absorbed the sugar solution and piped the tagged glucose molecules to their cells. As the fibers grew, they took on a yellowish tinge—and glowed bright green under ultraviolet light.
Glowing cotton wasn’t enough for Natalio. It took his group about six months to be sure they were actually delivering the fluorescent protein into the cotton cells and not just coating the fibers in it. Once they were certain, they decided to push the envelope with something very unnatural: magnets.
This time, Natalio’s team modified glucose with the rare earth metal dysprosium, making a molecule that acts like a magnet. And just like they did with the dye, the researchers fed it to cotton ovules and ended up with fibers with magnetic properties.
It’s not going to make a t-shirt you can decorate like your refrigerator, but that’s not the only use for magnetism. Almost all digital storage is done magnetically—in your phone, your computer, Amazon’s servers.
Natalio says this research shows the power of adapting natural processes. “If you understand a bit about how the biochemistry works and you respect that, then you’ll be able to integrate new functionality and eventually create new materials,” he says. All his group did was modify glucose molecules; the cotton ovules did all the work of incorporating them into the fibers.
These researchers aren’t the first to make augmented fibers. But past work has mostly been on synthetic fibers, like polyester, and has focused on coating the fibers rather than embedding the functionality inside them. Natalio argues that his approach is sturdier—the modifications his group made are fundamental to the fibers and can’t be worn away.
That said, their paper does show some evidence that the additions they made might change cotton’s properties for the worse. Natalio explains that the molecules they wove into the fibers’ structure appear to have disrupted the molecular architecture. In the case of the fluorescent cotton, that made the strands weaker than normal cotton.
But Natalio thinks that their use of cotton ovules—rather than the whole plant—may have something to do with that. He says the defects his group saw could be corrected if the whole plant could bring all its mechanisms to bear. He hopes to test that in future research, moving from the ovules to the entire cotton fruit and finally to full plants.
He also wants to experiment with adding different functionalities. Natalio wants to try adding the molecule diazobenzene, which can change its shape when exposed to the right light. Like the magnetic molecules, that could allow cotton fibers to be used as bits for storing digital information.
Cotton could be dyed blue before it’s picked, simplifying the production of blue jeans. Natalio also envisions cotton plants with unique molecular signatures, like barcodes. That would let manufacturers track their fabric from the seed to stores so they could promise their products were fully organic or 100% fair trade.
And he wants to branch out from cotton. Bacteria could be fed diazobenzene-modified glucose and grow into sheets for storing data. Or bamboo could be modified with carbon fibers to make it even stronger.
Natalio says he’s looking for corporate partners to help fund and direct his research. He hopes to see his technology commercialized.
