Nanotube fabric could let you charge your phone by walking

Wake Forest graduate student Corey Hewitt works with a sample of thermoelectric fabric in the school's Nanotechnology lab.

By Doug Gross, CNN

What if you could power up your smartphone with just a brisk walk?

That’s the promise of Power Felt, a new creation of nanotechnology researchers at Wake Forest University.

It’s a fabric, made up of tiny carbon nanotubes locked in flexible plastic fibers, that uses temperature differences to create a charge.

So, for example, you could slap a strip of it onto the back of your phone and hold it in your hand or stick it in your pocket while you walked. Since your body heat would be higher than the temperature outside, it would create one of those differentials and the felt would siphon off that extra heat, turning it into electrical power.

    “Heat is all around you,” said David Carroll, Director of the Center for Nanotechnology and Molecular Materials. “Heat differentials are everywhere.”

    He says all the energy that heat generates is wasted without a way to harness and move it. Enter Power Felt.

    Carroll’s research is featured in the current issue of NanoLetters, a leading nanotechnology journal. He says the product isn’t quite ready for market, but that the center is currently courting investors to help get it there.

    The felt probably isn’t ready to charge a phone all the way. But a regular day’s activity could add an hour or so to its battery life, Carroll said.

    “If you’re at the airport and your phone’s dead and you’re trying to get your wife on the phone to come get you, what you’re concerned about is being able to make that one extra call,” he said.

    Other uses could include using the heat inside a car to power its battery, lining solar panels to help them soak in even more of the sun’s rays, or lining emergency kits to power flashlights, radios and other tools.

    When reversed, the nanotubes can also move heat away, producing a cooling effect that could be helpful for medical care.

    “We’re going to go further and further with this,” Carroll said.

    The practice of taking research from a university lab and trying to market it is one that’s relatively recent, he said. But more and more, Carroll said he’s seeing academic work moving from the theoretical to the practical without the new technology needing to change hands.

    “Science can make a difference; science can solve stuff,” he said. “It’s not that basic science has goine away, but it is fascinating when you get into this kind of development of technology, and I see more and more of that happening.”