Monday, April 16, 2012

ENERGY SPECIAL..Battery running out? Use body heat to power up

A new material called Power Felt could charge up devices by turning heat into electricity

Comprised of tiny carbon nanotubes locked up in flexible plastic fibres and made to feel like fabric, Power Felt uses temperature differences – room temperature versus body temperature, for instance – to create a charge.
“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,” said Corey Hewitt, from Wake Forest University. “Generally thermoelectrics are an underdeveloped tech for harvesting energy, yet there is so much opportunity.”
Potential uses for Power Felt include lining automobile seats to boost battery power and service electrical needs, insulating pipes or collecting heat under roof tiles to lower electric bills, lining clothing or sports equipment to monitor performance, or wrapping wound sites to better track patients’ medical needs.
“Imagine it in an emergency kit, wrapped around a flashlight, powering a weather radio, charging a prepaid phone,” says David Carroll, head of the team leading the research. “Literally, just by sitting on your phone, Power Felt could provide relief during power outages.”
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 it can cost $1,000 per kilogram. Like silicon, researchers liken its affordability to demand in volume and think someday Power Felt would cost only $1 to add to a phone cover.
Currently Hewitt is evaluating several ways to add more nanotube layers and make them even thinner to boost the power output.
Although there’s more work to do before it’s ready for market, he says, “I imagine being able to make a jacket with a thermoelectric liner that gathers warmth from body heat. If the Power Felt is efficient enough, you could potentially power an iPod. It’s definitely within reach.”
The research appears in the leading nano technology journal Nano Letters.

(MM 120225)

No comments: