Nanotechnology Now

Our NanoNews Digest Sponsors





Heifer International

Wikipedia Affiliate Button


android tablet pc

Home > Press > Physicists tweak quantum force, reducing barrier to tiny devices

A scanning electron micrograph, taken with an electron microscope, shows the comb-like structure of a metal plate at the center of newly published University of Florida research on quantum physics. UF physicists found that corrugating the plate reduced the Casimir force, a quantum force that draws together very close objects. The discovery could prove useful as tiny “microelectromechanical” systems -- so-called MEMS devices that are already used in a wide array of consumer products -- become so small they are affected by quantum forces.

Yiliang Bao and Jie Zoue/University of Florida
A scanning electron micrograph, taken with an electron microscope, shows the comb-like structure of a metal plate at the center of newly published University of Florida research on quantum physics. UF physicists found that corrugating the plate reduced the Casimir force, a quantum force that draws together very close objects. The discovery could prove useful as tiny “microelectromechanical” systems -- so-called MEMS devices that are already used in a wide array of consumer products -- become so small they are affected by quantum forces.

Yiliang Bao and Jie Zoue/University of Florida

Abstract:
Cymbals don't clash of their own accord - in our world, anyway.

But the quantum world is bizarrely different. Two metal plates, placed almost infinitesimally close together, spontaneously attract each other.

What seems like magic is known as the Casimir force, and it has been well-documented in experiments. The cause goes to the heart of quantum physics: Seemingly empty space is not actually empty but contains virtual particles associated with fluctuating electromagnetic fields. These particles push the plates from both the inside and the outside. However, only virtual particles of shorter wavelengths — in the quantum world, particles exist simultaneously as waves — can fit into the space between the plates, so that the outward pressure is slightly smaller than the inward pressure. The result is the plates are forced together.

Now, University of Florida physicists have found they can reduce the Casimir force by altering the surface of the plates. The discovery could prove useful as tiny "microelectromechanical" systems — so-called MEMS devices that are already used in a wide array of consumer products — become so small they are affected by quantum forces.

Physicists tweak quantum force, reducing barrier to tiny devices

GAINESVILLE, FL | Posted on July 14th, 2008

"We are not talking about an immediate application," says Ho Bun Chan, an assistant professor of physics and the first author of a paper on the findings that appears today in the online edition of the journal Physical Review Letters.

"We are talking about, if the devices continue to be smaller and smaller, as the trend of miniaturization occurs, then the quantum effects could come into play."

More specifically, the finding could one day help reduce what MEMS engineers call "stiction" — when two very small, very close objects tend to stick together.

Although stiction has many causes — including, for example, the presence of water molecules that tend to clump together — the Casimir force can contribute. Such quantum effects could prove important as the separations between components in tiny machinery shrink from micrometer, or millionths of a meter, toward nanometer size, Chan said.

"A lot of people are thinking of ways to reduce stiction, and this research opens up one possibility," he said.

Dutch physicist Hendrik Casimir first predicted that two closely spaced metal plates would be mutually attracted in 1948. It took several decades, but in 1996, physicist Steve Lamoreaux, then at the University of Washington, performed the first accurate measurement of the Casimir force using a torsional pendulum, an instrument for measuring very weak forces.

Subsequently, in a paper published in Science in 2001, Chan and other members of a Bell Labs team reported tapping the Casimir force to move a tiny metal see-saw. The researchers suspended a metal sphere an extremely tiny but well-controlled distance above the see-saw to "push" it up and down. It was the first demonstration of the Casimir force affecting a micromechanical device.

In the latest research, the physicists radically altered the shape of the metal plates, corrugating them into evenly spaced trenches so that they resembled a kind of three-dimensional comb. They then compared the Casimir forces generated by these corrugated objects with those generated by standard plates, all also against a metal sphere.

The result? "The force is smaller for the corrugated object but not as small as we anticipated," Chan said, adding that if corrugating the metal reduced its total area by half, the Casimir force was reduced by only 30 to 40 percent.

Chan said the experiment shows that it is not possible to simply add the force on the constituent solid parts of the plate — in this case, the tines — to arrive at the total force. Rather, he said, "the force actually depends on the geometry of the object."

"Until now, no significant or nontrivial corrections to the Casimir force due to boundary conditions have been observed experimentally," wrote Lamoreaux, now at Yale University, in a commentary accompanying publication of the paper.

Besides Chan, the other authors of the paper are UF doctoral students Yiliang Bao and Jie Zou, and Bell Labs scientists Raymond Cirelli, Fred Klemens, William Mansfield and Chien-Shing Pai. The research was funded by the U.S. Department of Energy.

####

About University of Florida
UF is a major, public, comprehensive, land-grant, research university. The state's oldest, largest and most comprehensive university, Florida is among the nation's most academically diverse public universities. Florida has a long history of established programs in international education, research and service. It is one of only 17 public, land-grant universities that belongs to the Association of American Universities.

For more information, please click here

Contacts:

Writer
Aaron Hoover

352-392-0186

Source
Ho Bun Chan

352-392-6691

Copyright © University of Florida

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

Study finds long-term survival of human neural stem cells transplanted into primate brain April 23rd, 2014

High-Performance, Low-Cost Ultracapacitors Built with Graphene and Carbon Nanotubes: Future devices based on technology could bridge gap between batteries and conventional capacitors in portable electronics and hybrid electric vehicles April 23rd, 2014

Guo Lab Shows Potential of RNA as Heat-resistant Polymer Material for Nanoarchitectures April 23rd, 2014

National Space Society Congratulates SpaceX on the Success of CRS-3 and the First Flight of the Falcon 9R April 22nd, 2014

Govt.-Legislation/Regulation/Funding/Policy

High-Performance, Low-Cost Ultracapacitors Built with Graphene and Carbon Nanotubes: Future devices based on technology could bridge gap between batteries and conventional capacitors in portable electronics and hybrid electric vehicles April 23rd, 2014

Guo Lab Shows Potential of RNA as Heat-resistant Polymer Material for Nanoarchitectures April 23rd, 2014

Cloaked DNA nanodevices survive pilot mission: Successful foray opens door to virus-like DNA nanodevices that could diagnose diseased tissues and manufacture drugs to treat them April 22nd, 2014

Berkeley Lab Researchers Demonstrate First Size-based Chromatography Technique for the Study of Living Cells April 22nd, 2014

Discoveries

Study finds long-term survival of human neural stem cells transplanted into primate brain April 23rd, 2014

High-Performance, Low-Cost Ultracapacitors Built with Graphene and Carbon Nanotubes: Future devices based on technology could bridge gap between batteries and conventional capacitors in portable electronics and hybrid electric vehicles April 23rd, 2014

Guo Lab Shows Potential of RNA as Heat-resistant Polymer Material for Nanoarchitectures April 23rd, 2014

Berkeley Lab Researchers Demonstrate First Size-based Chromatography Technique for the Study of Living Cells April 22nd, 2014

Announcements

Study finds long-term survival of human neural stem cells transplanted into primate brain April 23rd, 2014

High-Performance, Low-Cost Ultracapacitors Built with Graphene and Carbon Nanotubes: Future devices based on technology could bridge gap between batteries and conventional capacitors in portable electronics and hybrid electric vehicles April 23rd, 2014

Guo Lab Shows Potential of RNA as Heat-resistant Polymer Material for Nanoarchitectures April 23rd, 2014

National Space Society Congratulates SpaceX on the Success of CRS-3 and the First Flight of the Falcon 9R April 22nd, 2014

Quantum nanoscience

A new key to unlocking the mysteries of physics? Quantum turbulence April 21st, 2014

Quantum manipulation: Filling the gap between quantum and classical world April 14th, 2014

Scientists in Singapore develop novel ultra-fast electrical circuits using light-generated tunneling currents April 10th, 2014

Quantum Photon Properties Revealed in Another Particle—the Plasmon April 5th, 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