Clothing Created to Block Flu, Colds
Nanotech Fabric Grabs Airborne Bugs -- and You Don't Even Have to Wash It
By LEE DYE
May 9, 2007 —
Would you like a coat that can snatch viruses out of the air before they can give you a cold?
How about a shirt that eats smog, letting you breathe clean air? Or a dress that destroys harmful bacteria and even protects you from toxic gases?
And wouldn't it be nice if you never had to wash your duds again?
Well, guess what? Scientists and engineers and a clever design student at Cornell University have come up with clothes that do all of that and more.
"Initially we were just doing this for fun," said chemical engineer Juan Hinestroza, who specializes in fiber science. But as soon as a couple of outfits designed by Olivia Ong hit the runway during a fashion show at Cornell, it became a lot more than just fun.
Protective Clothing Could Be Priceless, Literally
"We didn't think this was going to make a big noise, but it has," Hinestroza said. He's already been called in to brief the military on the project, because clothes that protect against all kinds of poisons could be priceless during chemical or biological warfare.
Unfortunately, at this point priceless is pretty much where it stands. The two outfits created by Ong cost thousands of bucks, but once the technology is perfected that should come down.
The garments are unique in that they are coated with microscopic nanoparticles designed to capture viruses and bacteria, but you wouldn't know that if you just looked at them. They look like glitzy outfits that expand the realm of "functional clothing."
The project began when Ong, who will graduate in December, approached Hinestroza with what he first thought was a "crazy idea." Ong said that she was familiar with nanotechnology and that she wondered whether it could somehow be incorporated into her fashion line, which she calls Glitterati. The idea sprang from the years when she lived in Los Angeles and had to breathe all that smog.
Inspired by Smog
"There's a lot of pollution and smog, and I thought it would be interesting if we could use technology and clothing to prevent it," she said. So she took her request to Hinestroza's lab.
Out of that came what Hinestroza calls a "personal air purification system," but he took it much further than Ong had asked.
Now, Hinestroza is working on nanoparticles that can decompose gases, like ozone, thus truly reducing the smog. And he's even produced colors without the use of dyes, by creating nanoparticles that are just the right size to reflect the desired color.
The trick, he said, is to use nanoparticles that are about the same size as the viruses and bacteria he wants to capture.
"You wouldn't try to kill a mosquito with a gun," he said.
The particles he uses are a mere five to 20 nanometers in size. A nanometer is one-billionth of a meter. They cling to the surface of the cotton fabric because the particles and the fabric have opposite electrostatic charges. The particles are metals that can recognize specific viruses or bacteria, and thus trap them.
Silver, for example, is a natural antibacterial agent.
Particles Smaller Than Light Waves
The particles are much smaller than a wavelength of visible light, which averages around 400 nanometers, so they can reflect only part of the light spectrum, thus producing colors with the precise wavelength that matches their size. For now, that means red, blue or yellow.
So when Ong joined the team, she didn't have all the colors she would normally use in her Glitterati.
"They pretty much told me what I was going to get," she said.
So she plunged in, fighting a two-week deadline to get the garments ready for the fashion show.
"The first time it was really a mess," she said. "I had to use the fabric they already had in the lab, and it came out splotchy."
The second time, though, was a charm. The denim jacket has material coated with nanoparticles strategically placed around the neck, on the ends of sleeves, around the hem, and on a hood and scarf. The dress is coated around the neck and on the sleeves.
Not sure how they would show at New York Fashion Week, but to a science writer, they look smashing.
And it's not over yet. Hinestroza has gotten into the flow now, and he's looking toward the future. He wants to come up with a way to move the particles around on the fabric, rearranging them so that he can change colors.
"So you could go to the office with a blue shirt, and you have a party at night and you don't want to go home," he said. "You supply an electric field [thus moving the particles] and your shirt becomes black and you can go to your party."
Sound fabulous? Hinestroza admits that's a ways away right now. But give him a couple of weeks.
And what's that bit about never needing washing? The size of the particles makes it harder for the fabric to absorb stains, the scientists say, so there's less need to wash the garment.
But if that catches on, maybe Hinestroza's lab ought to come up with a nanoparticle that captures odors.