Nanotechnology aims to cure smelly feet

Researchers believe nanotechnology could someday help build tiny supercomputers or solve many of the world's energy problems. More immediately, a company in Pennsylvania hopes to use nanoparticles to create less-stinky socks.

NanoHorizons, based in State College, Pa., has begun to sell a line of metallic nanoparticles that are compatible with standard polymer manufacturing processes. This means that silver, gold and other metals that kill bacteria and odor-causing microbes can be incorporated into shoes, athletic equipment and other plastic or nylon products.

"We're working with a company that does socks right now," said Dan Hayes, director of operations for NanoHorizons. The socks should be out in about a year.

Currently, manufacturers can incorporate these metals into products by mixing a bulk form of the material into a polymer or evaporating a layer of metal onto a surface. This method, however, requires that manufacturers mix quite a bit of metal into the product, which adds weight and cost and which can change durability or other characteristics, said Hayes.

By contrast, NanoHorizons has come up with particles, shaped like spheres or rods, that are designed to greatly increase the available surface area of the metal that can be used in a microbe-killing chemical reaction. The idea is that manufacturers can put in far less metal to achieve the same results that layers of ordinary bulk metals would achieve, or use the same amount of metal and kill more microbes. NanoHorizons claims its particles are 20 to 100 times more efficacious in killing bacteria than similar metals in bulk form.

Nanotechnology--the art of making products out of components and/or molecules that measure less than 100 nanometers (a nanometer is a billionth of a meter)--is slowly but surely emerging as a technology market.

Although computer scientists will likely one day create chips with designer molecules, most of the "nano" advances that come out over the next few years will appear in ordinary products. Car manufacturers are mixing nanoparticles into windshields to reduce glare. Stain-free pants include nanoparticles that repel most substances.

NanoHorizons developed its first nanoparticles in conjunction with a medical manufacturer that makes devices that get implanted in a person's body, Hayes said. The basic technology is now being ported to consumer devices. Some of the intellectual property behind the company comes from Pennsylvania State University.

The company is largely promoting its silver and gold nanoparticles, which come in solutions that range in price from $100 to $400 a liter. Other metals, such as copper, can be used. Mercury also can be used, Hayes said, but there are toxicity issues. The silver and gold particles themselves range in size from 10 nanometers to 90 nanometers.

The added cost depends on what the product manufacturer wants to accomplish. Incorporating enough nanoparticles to substantially reduce foot odor will probably add around 20 cents to a dollar to the cost of a product, Hayes said. A medical device, which requires a greater deal of bacterial control, would cost more.

Ancient Greeks and Romans, when they weren't eating off lead plates, used silver and gold to kill odors, Hayes noted. Silver has also been added to the socks of troops in jungle environments.

The 12-person company has received funding from, among others, Pulsar Ventures and Life Sciences Greenhouse.