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New piezoelectric device harvests wasted energy from electronics

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October 11, 2010

The piezoelectric CNF-PZT Cantilever device

The piezoelectric CNF-PZT Cantilever device

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Piezoelectric generators that harness otherwise wasted energy from vibrations has been proposed for capturing energy in everything from shoes to roads. Now a new device made out of piezoelectric material by researchers at Louisiana Tech University could allow a wide range of electronic devices to harvest their own wasted operational energy, resulting in devices that are much more energy efficient. It even offers the potential to perpetually power micro and nano devices, such as biomedical devices or remotely located sensors and communication nodes.

The device, designed and fabricated by Dr. Long Que, assistant professor of electrical engineering at Louisiana Tech, uses a cantilever made out of material capable of converting distortions to itself into electrical energy. It is coated with a carbon nanotube film on one side that causes the cantilever to bend back and forth repeatedly when it absorbs light and/or heat. This causes the piezoelectric material to generate power for as long as the light and/or heat source is active.

“The greatest significance of this work is that it offers us a new option to continuously harvest both solar and thermal energy on a single chip, given the self-reciprocating characteristics of the device upon exposure to light and/or thermal radiation,” said Que. “This characteristic might enable us to make perpetual micro/nano devices and micro/nanosystems, and could significantly impact the wireless sensory network.”

The research team’s experiments showed that the device, called a CNF-PZT Cantilever, was able to generate enough power to operate some low-power microsensors and integrated sensors. One of the most impressive aspects of the system was its ability to “self-reciprocate” – perpetually produce energy without needing to draw power from an external energy source.

The researchers say that this self-reciprocation occurs from the cantilever’s constant absorption of photons and its high electrical conduction and rapid thermal dissipation into the environment. The team says it has routinely observed this self-reciprocation phenomenon, not only in the lab, but also in the field under sunlight.

“It is truly a hybrid energy-harvesting technology,” Que said. “My lab has been optimizing and making great progress on this technology in an effort to enhance its efficiency and overall performance, indicating great promise for this technology.”

About the Author
Darren Quick Darren's love of technology started in primary school with a Nintendo Game & Watch Donkey Kong (still functioning) and a Commodore VIC 20 computer (not still functioning). In high school he upgraded to a 286 PC, and he's been following Moore's law ever since. This love of technology continued through a number of university courses and crappy jobs until 2008, when his interests found a home at Gizmag.   All articles by Darren Quick
5 Comments

This is on the right track. Not only do we need to find renewable energy sources that can meet the energy demands of the future, we need to work on the other side of the equation too--we need to design electrical devices that use less energy. One way that we can do that is by collecting the heat, vibration, and radiation that our devices emit (which we currently throw away), transform them into electricity, and feed the electricity back into the device. Every little bit of self-generated electricity is less power the device needs to draw.

See this page for more info about the known methods:

http://en.wikipedia.org/wiki/Energy_harvesting

4Freedom
12th October, 2010 @ 05:15 am PDT

"Dr. Long Que" - Wow, what a name!

Facebook User
12th October, 2010 @ 11:58 am PDT

Sounds good, but I wonder about the efficiency of this energy conversion, which I suspect to be a single digit figure!

Mohsene
12th October, 2010 @ 09:14 pm PDT

Huge power from speed bumps, intended to slow down a vehicle anyway... at a toll-booth, all those cars and trucks could probably power the booth without much outside power during high traffic times.

Matt Rings
12th October, 2010 @ 10:53 pm PDT

sounds great, but not self-reciprocating. you say yourselves that it's absorbing photons; those photons from the sun or other light source; that counts as an "external energy source" in my book.

jcomeau
13th October, 2010 @ 04:14 am PDT
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