Nanotechnology Converts Heat to Power With Fabric

Carbon nanotube bundles

What if by merely sitting in your car, or by wearing a particular jacket, you could generate power? Or maybe by insulating your pipes, you could fill a battery every time you run the hot water? That's the potential held by a new nanotechnology that can generate electricity from the surrounding heat.

The Center for Nanotechnology and Molecular Materials at Wake Forest University is behind the research, and has developed a material called Power Felt, a fabric-like device that can convert body heat into an electrical current.

Made of carbon nanotubes held within plastic fibers, the material has the same look and feel of felt, a material well known for keeping in the heat. However, this felt will do something far more interesting with it. When held close to a warm body, it can take temperature differences and create a charge. That means power can be generated just by insulating something, from people to pipes and all sorts of things in between.

"We waste a lot of energy in the form of heat. For example, recapturing a car's energy waste could help improve fuel mileage and power the radio, air conditioning or navigation system," says researcher and Wake Forest graduate student Corey Hewitt in a press release. "Generally thermoelectrics are an underdeveloped technology for harvesting energy, yet there is so much opportunity."

The team behind Power Felt sees it being useful in everything from emergency kits, where enough power can be generated for flashlights or radios, to charging the MP3 players and heart rate monitors of joggers, to lowering home electricity bills.

Cost has prevented thermoelectrics from being used more widely in consumer products. Standard thermoelectric devices use a much more efficient compound called bismuth telluride to turn heat into power in products including mobile refrigerators and CPU coolers, but researchers say it can cost $1,000 per kilogram. Like silicon, they liken Power Felt's affordability to demand in volume and think someday it could cost only $1 to add to a cell phone cover... Currently, 72 stacked layers in the fabric yield about 140 nanowatts of power. The team is evaluating several ways to add more nanotube layers and make them even thinner to boost the power output.

While cost has been prohibitive so far, this isn't stopping the researchers from seeking out investors for commercial production. This could be technology we see in a matter of years.

Nanotechnology Converts Heat to Power With Fabric
A "Power Felt" developed by researchers can use your body heat to charge up a battery.

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