Nanotechnology Now

Our NanoNews Digest Sponsors





Heifer International

Wikipedia Affiliate Button


android tablet pc

Home > Press > Nanoscale pillars could radically improve conversion of heat to electricity

 This shows an atomic-scale model of a nanophononic metamaterial. The vibrations caused by the pillar slow down the horizontal flow of heat through the thin film.

Credit: Mahmoud Hussein
This shows an atomic-scale model of a nanophononic metamaterial. The vibrations caused by the pillar slow down the horizontal flow of heat through the thin film.

Credit: Mahmoud Hussein

Abstract:
University of Colorado Boulder scientists have found a creative way to radically improve thermoelectric materials, a finding that could one day lead to the development of improved solar panels, more energy-efficient cooling equipment, and even the creation of new devices that could turn the vast amounts of heat wasted at power plants into more electricity.

Nanoscale pillars could radically improve conversion of heat to electricity

Boulder, CO | Posted on February 20th, 2014

The technique—building an array of tiny pillars on top of a sheet of thermoelectric material—represents an entirely new way of attacking a century-old problem, said Mahmoud Hussein, an assistant professor of aerospace engineering sciences who pioneered the discovery.

The thermoelectric effect, first discovered in the 1800s, refers to the ability to generate an electric current from a temperature difference between one side of a material and the other. Conversely, applying an electric voltage to a thermoelectric material can cause one side of the material to heat up while the other stays cool, or, alternatively, one side to cool down while the other stays hot.

Devices that incorporate thermoelectric materials have been used in both ways: to create electricity from a heat source, such as the sun, for example, or to cool precision instruments by consuming electricity.

However, the widespread use of thermoelectric materials has been hindered by a fundamental problem that has kept scientists busy for decades. Materials that allow electricity to flow through them also allow heat to flow through them. This means that at the same time a temperature difference creates an electric potential, the temperature difference itself begins to dissipate, weakening the current it created.

Until the 1990s, scientists addressed this problem by looking for materials with intrinsic properties that allowed electricity to flow more easily than heat.

"Until 20 years ago, people were looking at the chemistry of the materials," Hussein said. "And then nanotechnology came into the picture and allowed researchers to engineer the materials for the properties they wanted."

Using nanotechnology, material physicists began creating barriers in thermoelectric materials—such as holes or particles—that impeded the flow of heat more than the flow of electricity. But even under the best scenario, the flow of electrons—which carry electric energy—also was slowed.

In a new study published in the journal Physical Review Letters, Hussein and doctoral student Bruce Davis demonstrate that nanotechnology could be used in an entirely different way to slow the heat transfer without affecting the motion of electrons.

The new concept involves building an array of nanoscale pillars on top of a sheet of a thermoelectric material, such as silicon, to form what the authors call a "nanophononic metamaterial." Heat is carried through the material as a series of vibrations, known as phonons. The atoms making up the miniature pillars also vibrate at a variety of frequencies. Davis and Hussein used a computer model to show that the vibrations of the pillars would interact with the vibrations of the phonons, slowing down the flow of heat. The pillar vibrations are not expected to affect the electric current.

The team estimates that their nanoscale pillars could reduce the heat flow through a material by half, but the reduction could be significantly stronger because the calculations were made very conservatively, Hussein said.

"If we can improve thermoelectric energy conversion significantly, there will be all kinds of important practical applications," Hussein said. These include recapturing the waste heat emitted by different types of equipment—from laptops to cars to power plants—and turning that heat into electricity. Better thermoelectrics also could vastly improve the efficiency of solar panels and refrigeration devices.

The next step is for Hussein to partner with colleagues in the physics department and other institutions to fabricate the pillars so that the idea can be tested in the lab. "This is still early in the phase of laboratory demonstration but the remaining steps are within reach."

Hussein also hopes to further refine the models he used to gain additional insight into the underlying physics. "A team of highly motivated Ph.D. students are working with me around the clock on this project," he said.

###

The research was funded by the National Science Foundation.

####

For more information, please click here

Contacts:
Mahmoud Hussein

303-492-3177

Copyright © University of Colorado at Boulder

If you have a comment, please Contact us.

Issuers of news releases, not 7th Wave, Inc. or Nanotechnology Now, are solely responsible for the accuracy of the content.

Bookmark:
Delicious Digg Newsvine Google Yahoo Reddit Magnoliacom Furl Facebook

Related Links

Read the study at:

Related News Press

News and information

Nano-supercapacitors for electric cars July 25th, 2014

New imaging agent provides better picture of the gut July 25th, 2014

Breakthrough laser experiment reveals liquid-like motion of atoms in an ultra-cold cluster: University of Leicester research team unlocks insights into creation of new nano-materials July 25th, 2014

Scientists Test Nanoparticle "Alarm Clock" to Awaken Immune Systems Put to Sleep by Cancer July 25th, 2014

Thin films

Oregon chemists eye improved thin films with metal substitution: Solution-based inorganic process could drive more efficient electronics and solar devices July 21st, 2014

Even geckos can lose their grip July 9th, 2014

Shrinky Dinks close the gap for nanowires July 1st, 2014

Micro-manufacturing breakthrough is wired for sound June 24th, 2014

Govt.-Legislation/Regulation/Funding/Policy

New imaging agent provides better picture of the gut July 25th, 2014

A*STAR and industry form S$200M semiconductor R&D July 25th, 2014

NNCO Announces an Interactive Webinar: Progress Review on the Coordinated Implementation of the National Nanotechnology Initiative 2011 Environmental, Health, and Safety Research Strategy July 23rd, 2014

Nano-sized Chip "Sniffs Out" Explosives Far Better than Trained Dogs: TAU researcher's groundbreaking sensor detects miniscule concentrations of hazardous materials in the air July 23rd, 2014

Discoveries

New imaging agent provides better picture of the gut July 25th, 2014

Breakthrough laser experiment reveals liquid-like motion of atoms in an ultra-cold cluster: University of Leicester research team unlocks insights into creation of new nano-materials July 25th, 2014

Scientists Test Nanoparticle "Alarm Clock" to Awaken Immune Systems Put to Sleep by Cancer July 25th, 2014

Iranian Scientists Produce Transparent Nanocomposite Coatings with Longer Lifetime July 24th, 2014

Materials/Metamaterials

Silicene Labs Announces the Launch of 2D Materials Briefing Book™ and 2D Materials Road-Heat Map™: Contributors Include One of the World's Foremost 2D Materials Scientists July 25th, 2014

Silicene Labs Announces the Launch of Patent-Pending, 2D Materials Composite Index™ : The Initial 2D Materials Composite Index™ for Q2 2014 Is: 857.3; Founders Include World-Renowned Physicist and Seasoned Business and IP Professionals July 24th, 2014

Iranian Scientists Produce Transparent Nanocomposite Coatings with Longer Lifetime July 24th, 2014

Penn Study: Understanding Graphene’s Electrical Properties on an Atomic Level July 22nd, 2014

Announcements

Nano-supercapacitors for electric cars July 25th, 2014

New imaging agent provides better picture of the gut July 25th, 2014

Breakthrough laser experiment reveals liquid-like motion of atoms in an ultra-cold cluster: University of Leicester research team unlocks insights into creation of new nano-materials July 25th, 2014

Scientists Test Nanoparticle "Alarm Clock" to Awaken Immune Systems Put to Sleep by Cancer July 25th, 2014

Interviews/Book Reviews/Essays/Reports/Podcasts/Journals

Silicene Labs Announces the Launch of 2D Materials Briefing Book™ and 2D Materials Road-Heat Map™: Contributors Include One of the World's Foremost 2D Materials Scientists July 25th, 2014

New imaging agent provides better picture of the gut July 25th, 2014

Breakthrough laser experiment reveals liquid-like motion of atoms in an ultra-cold cluster: University of Leicester research team unlocks insights into creation of new nano-materials July 25th, 2014

Scientists Test Nanoparticle "Alarm Clock" to Awaken Immune Systems Put to Sleep by Cancer July 25th, 2014

Energy

Oregon chemists eye improved thin films with metal substitution: Solution-based inorganic process could drive more efficient electronics and solar devices July 21st, 2014

Steam from the sun: New spongelike structure converts solar energy into steam July 21st, 2014

3-D nanostructure could benefit nanoelectronics, gas storage: Rice U. researchers predict functional advantages of 3-D boron nitride July 15th, 2014

Nanotechnology that will impact the Security & Defense sectors to be discussed at NanoSD2014 conference July 8th, 2014

Photonics/Optics/Lasers

NUS scientists use low cost technique to improve properties and functions of nanomaterials: By 'drawing' micropatterns on nanomaterials using a focused laser beam, scientists could modify properties of nanomaterials for effective applications in photonic and optoelectric applicat July 22nd, 2014

Carbyne morphs when stretched: Rice University calculations show carbon-atom chain would go metal to semiconductor July 21st, 2014

Tiny laser sensor heightens bomb detection sensitivity July 19th, 2014

Future Electronics May Depend on Lasers, Not Quartz July 17th, 2014

NanoNews-Digest
The latest news from around the world, FREE



  Premium Products
NanoNews-Custom
Only the news you want to read!
 Learn More
NanoTech-Transfer
University Technology Transfer & Patents
 Learn More
NanoStrategies
Full-service, expert consulting
 Learn More














ASP
Nanotechnology Now Featured Books




NNN

The Hunger Project







© Copyright 1999-2014 7th Wave, Inc. All Rights Reserved PRIVACY POLICY :: CONTACT US :: STATS :: SITE MAP :: ADVERTISE