Energy News  





. Squeezed Crystals Deliver More Volts Per Jolt

High-performance piezoelectrics have also opened up new possibilities for "energy harvesting," using ambient motion and vibration to generate electricity where batteries or other power sources are impractical or unavailable.
by Staff Writers
Washington DC (SPX) Feb 01, 2008
A discovery by scientists at the Carnegie Institution has opened the door to a new generation of piezoelectric materials that can convert mechanical strain into electricity and vice versa, potentially cutting costs and boosting performance in myriad applications ranging from medical diagnostics to green energy technologies.

High-performance piezoelectric materials used today, such as those in probes for medical ultrasound, are specially grown crystals of mixed composition known as "solid solutions," making them difficult to study and expensive to manufacture. But in the January 31 Nature a research team led by Ronald Cohen and Russell Hemley of the Carnegie Institution's Geophysical Laboratory report that at high pressure pure crystals of lead titanate show the same transitions seen in more complex materials.

Moreover, theory predicts that lead titanate under pressure has the largest piezoelectric response of any material known. This suggests the exciting possibility of low-cost but extremely high-performance piezoelectrics.

"The most useful piezoelectric materials have a critical range of compositions called the morphotopic phase boundary, where the crystal structure changes and the piezoelectric properties are maximal," says Muhtar Ahart, a co-author of the study. "These are usually complex, engineered, solid solutions. But we showed that a pure compound can display a morphotopic phase boundary under pressure."

For the study, the researchers placed powdered crystals of lead titanate in a device called a diamond anvil cell, which can generate pressures exceeding those at the center of the Earth. They monitored the changes in crystal structure with pressure using high-energy X-ray beams of the Advanced Photon Source at Argonne National Laboratory in Illinois. Using this data and calculations based on first-principle theoretical computations, the researchers were able to determine the piezoelectric properties of the pure crystals at different pressures.

"It turns out that complex microstructures or compositions are not necessary to obtain strong piezoelectricity," says Ahart.

The use of piezoelectrics has boomed in recent years and is rapidly expanding. Their ability to convert mechanical energy to electric energy and vice versa has made them invaluable for acoustic transducers for sonar and medical ultrasound, and for tiny, high-precision pumps and motors for medical and other applications. High-performance piezoelectrics have also opened up new possibilities for "energy harvesting," using ambient motion and vibration to generate electricity where batteries or other power sources are impractical or unavailable.

"This is a field in which theory, experiment, and material development work side-by-side," says Ronald Cohen, a staff scientist at the Carnegie Institution and a co-author of the study. "Delineating the underlying physics of piezoelectric materials will make it easier to develop new materials and improve existing ones. We're now poised on the edge of hugely expanded applications of these technologies."

Community
Email This Article
Comment On This Article

Related Links
Carnegie Institution
Powering The World in the 21st Century at Energy-Daily.com




Tempur-Pedic Mattress Comparison

Newsletters :: SpaceDaily Express :: SpaceWar Express :: TerraDaily Express :: Energy Daily
XML Feeds :: Space News :: Earth News :: War News :: Solar Energy News
Nuclear, solar and geothermal energy pushed at Philippine summit
Manila (AFP) Jan 30, 2008
The Philippine government should seriously consider other sources of energy such as nuclear, solar and geothermal rather than rely on oil, an energy summit in Manila was told Wednesday.

.
Get Our Free Newsletters Via Email
  



  • Analysis: Shell to shut again in Nigeria
  • Squeezed Crystals Deliver More Volts Per Jolt
  • Analysis: One strategy for Iraq oil, power
  • Analysis: IPI faces dangers, hurdles

  • French PM to visit Japan for nuclear talks: official
  • Areva says it is ready to build 12 reactors in South Africa
  • French Niger Uranium Mines Under Direct Threat From Tuareg Nomads
  • UN team goes inside Japan's quake-hit nuclear plant

  • New Model Revises Estimates Of Terrestrial Carbon Dioxide Uptake
  • A Breathable Earth
  • Researchers Find Origin Of Breathable Atmosphere Half A Billion Years Ago
  • Study Reveals Lakes A Major Source Of Prehistoric Methane

  • FAO warns of 'alarming' loss of mangroves
  • Brazil takes action to stop alarming deforestation of Amazon
  • Forests Could Benefit When Fall Color Comes Late
  • Rwanda's Gishwati Forest Selected As Site For Historic Conservation Project

  • African Seed Collection First To Arrive In Norway On Route To Arctic Seed Vault
  • Study: African fruit is untapped resource
  • Climate change could devastate South Asia, Africa crops: study
  • Chinese dumplings trigger food scare in Japan

  • Japan's ruling coalition backs down on fuel tax -- for now
  • Global automakers output hit by China snow storms
  • Japan's TEPCO to test park and charge system
  • China's auto production to exceed 10 mln in 2008: official

  • China to build 97 new airports by 2020
  • EADS offers to build military, civilian aircraft in US
  • Qatar Airways looking to natural gas fuel
  • Purdue Wind Tunnel Key For Hypersonic Vehicles And Future Space Planes

  • Nuclear Power In Space - Part 2
  • Nuclear Power In Space
  • Outside View: Nuclear future in space

  • The content herein, unless otherwise known to be public domain, are Copyright 1995-2007 - SpaceDaily.AFP and UPI Wire Stories are copyright Agence France-Presse and United Press International. ESA Portal Reports are copyright European Space Agency. All NASA sourced material is public domain. Additional copyrights may apply in whole or part to other bona fide parties. Advertising does not imply endorsement,agreement or approval of any opinions, statements or information provided by SpaceDaily on any Web page published or hosted by SpaceDaily. Privacy Statement