Nanotechnology Now







Heifer International

Wikipedia Affiliate Button


DHgate

Home > Press > New player in electron field emitter technology makes for better imaging and communications

NIST's silicon carbide field emitter produces a flow of electrons comparable to hot sources, but without the need for heat. By dissolving much of the material away to make a porous structure with a large surface area, NIST scientists ensured that as an electron emission point on an individual spike wears out, another is available to take its place, making the array more durable as a whole.

Credit: Sharifi/NIST
NIST's silicon carbide field emitter produces a flow of electrons comparable to hot sources, but without the need for heat. By dissolving much of the material away to make a porous structure with a large surface area, NIST scientists ensured that as an electron emission point on an individual spike wears out, another is available to take its place, making the array more durable as a whole.

Credit: Sharifi/NIST

Abstract:
Scientists at the National Institute of Standards and Technology (NIST) and the University of Maryland, College Park, have built a practical, high-efficiency nanostructured electron source. Described in the journal Nanotechnology*, this new, patent-pending technology could lead to improved microwave communications and radar, and more notably to new and improved X-ray imaging systems for security and health-care applications.

New player in electron field emitter technology makes for better imaging and communications

Gaithersburg, MD | Posted on March 9th, 2013

While thermionic electron sources such as the hot filaments inside cathode ray tubes have largely been replaced by LEDs and liquid crystals for display screens and televisions, they are still used to produce microwaves for radar and X-rays for medical imaging. Thermionic sources use an electric current to boil electrons off the surface of a wire filament, similar to the way an incandescent light bulb uses an electric current to heat a wire filament until it glows.

And like an incandescent light bulb, thermionic sources are generally not very energy efficient. It takes a lot of power to boil off the electrons, which spew in every direction. Those that aren't lost have to be captured and focused using a complicated system of electric and magnetic fields. Field emission electron sources require much less power and produce a much more directional and easily controllable stream of electrons.

To build their field emission source, the NIST team took a tough material—silicon carbide—and used a room-temperature chemical process to make it highly porous like a sponge. They then patterned it into microscopic emitting structures in the shape of pointed rods or sharp-edged fins. When an electric field is applied, these novel field emitters can produce an electron flow comparable to a thermionic source but without all the disadvantages—and with many advantages.

According to co-inventor Fred Sharifi, the new field emitters have inherently fast response times compared with thermionic sources, and the absence of heat makes it easier to create arrays of sources. Moreover, the porous nanostructure of the emitters makes them very reliable. Even if the emitter surface wears away during use—a common problem—the newly exposed material continues to work just as well.

Sharifi says that the NIST field emitters hold the potential to enhance the resolution and quality of X-ray images and allow for new modes of detection.

"X-ray images are based on the density of the material being examined, which limits their ability to see certain types of materials, including some types of explosives," says Sharifi. "Our field emitter will let us see not just that something is there, but, because we can build large arrays and place them at different angles, we can identify the material in question by looking at how the X-rays coming from different directions scatter from the object."

The technology is available for licensing through NIST's Technology Partnerships Office.

*M. Kang, H. Lezec and F. Sharifi. Stable field emission from nanoporous silicon carbide. Nanotechnology. 24 (2013) 065201.

####

For more information, please click here

Contacts:
Mark Esser

301-975-8735

Copyright © National Institute of Standards and Technology (NIST)

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 News Press

News and information

Antibacterial Ceramic Nanoparticles, Appropriate Material for Medical Devices May 3rd, 2015

Oxford Instruments announces winners of the 2015 Sir Martin Wood Science Prize for China May 2nd, 2015

Time Dependant Spectroscopy of Microscopic Samples: CRAIC TimePro™ software is used with CRAIC Technologies microspectrometers to measure the kinetic UV-visible-NIR, Raman and fluorescence spectra of microscopic sample areas May 2nd, 2015

ORNL researchers probe chemistry, topography and mechanics with one instrument May 2nd, 2015

Production of Industrial Nano-Membrane for Water, Wastewater Purification Device in Iran May 2nd, 2015

Imaging

Time Dependant Spectroscopy of Microscopic Samples: CRAIC TimePro™ software is used with CRAIC Technologies microspectrometers to measure the kinetic UV-visible-NIR, Raman and fluorescence spectra of microscopic sample areas May 2nd, 2015

ORNL researchers probe chemistry, topography and mechanics with one instrument May 2nd, 2015

Laboratories

ORNL researchers probe chemistry, topography and mechanics with one instrument May 2nd, 2015

Govt.-Legislation/Regulation/Funding/Policy

ORNL researchers probe chemistry, topography and mechanics with one instrument May 2nd, 2015

Making robots more human April 29th, 2015

Artificial photosynthesis could help make fuels, plastics and medicine April 29th, 2015

Research seeks alternatives for reducing bacteria in fresh produce using nanoengineering April 29th, 2015

Discoveries

Antibacterial Ceramic Nanoparticles, Appropriate Material for Medical Devices May 3rd, 2015

ORNL researchers probe chemistry, topography and mechanics with one instrument May 2nd, 2015

Novel superconducting undulator provides first x-ray light at ANKA May 1st, 2015

Engineering a better solar cell: UW research pinpoints defects in popular perovskites May 1st, 2015

Announcements

Antibacterial Ceramic Nanoparticles, Appropriate Material for Medical Devices May 3rd, 2015

Nanometrics to Present at the B. Riley & Co. 16th Annual Investor Conference May 2nd, 2015

Time Dependant Spectroscopy of Microscopic Samples: CRAIC TimePro™ software is used with CRAIC Technologies microspectrometers to measure the kinetic UV-visible-NIR, Raman and fluorescence spectra of microscopic sample areas May 2nd, 2015

ORNL researchers probe chemistry, topography and mechanics with one instrument May 2nd, 2015

Patents/IP/Tech Transfer/Licensing

Novel superconducting undulator provides first x-ray light at ANKA May 1st, 2015

Long Island Capital Alliance Announces Participants for Brookhaven National Laboratory Technology Transfer Capital Forum on May 8: Keynote Speaker Dr. Doon Gibbs, Director of Brookhaven National Laboratory April 16th, 2015

MIT sensor detects spoiled meat: Tiny device could be incorporated into 'smart packaging' to improve food safety April 15th, 2015

Heat-Converting Material Patents Licensed April 8th, 2015

Research partnerships

Electron chirp: Cyclotron radiation from single electrons measured directly for first time: Method has potential to measure neutrino mass and look beyond the Standard Model of the universe April 29th, 2015

Weighing -- and imaging -- molecules one at a time April 28th, 2015

SUNY Poly and Sematech Announce Air Products Joins Cutting-Edge CMP Center At Albany Nanotech Complex April 28th, 2015

When mediated by superconductivity, light pushes matter million times more April 28th, 2015

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