Navigation Links
Physicists tweak quantum force, reducing barrier to tiny devices
Date:7/14/2008

GAINESVILLE, Fla. 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.

"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.


'/>"/>

Contact: Ho Bun Chan
hochan@phys.ufl.edu
352-392-6691
University of Florida
Source:Eurekalert  

Related biology technology :

1. Physicists pin down spin of surface atoms
2. Sheet of carbon atoms acts like a billiard table, physicists find
3. Sheet of carbon atoms acts like a billiard table, physicists find
4. Physicists discover gold can be magnetic on the nanoscale
5. Physicists discover how fundamental particles lose track of quantum mechanical properties
6. UM physicists show electrons can travel over 100 times faster in graphene than in silicon
7. Physicists saved from drowning in complexities of wetting theory
8. New unifying theory of lasers advanced by physicists
9. Discovery by UC Riverside physicists could enable development of faster computers
10. UBC physicists develop impossible technique to study and develop superconductors
11. Imaging quantum entanglement
Post Your Comments:
*Name:
*Comment:
*Email:
Related Image:
Physicists tweak quantum force, reducing barrier to tiny devices
(Date:6/23/2016)... Apellis Pharmaceuticals, Inc. today announced positive ... its complement C3 inhibitor, APL-2. The trials were ... studies designed to assess the safety, tolerability, pharmacokinetics ... healthy adult volunteers. Forty subjects were ... dose (ranging from 45 to 1,440mg) or repeated ...
(Date:6/23/2016)... , June 23, 2016 On Wednesday, ... at 4,833.32, down 0.22%; the Dow Jones Industrial Average edged ... closed at 2,085.45, down 0.17%. Stock-Callers.com has initiated coverage on ... ), Nektar Therapeutics (NASDAQ: NKTR ), Aralez Pharmaceuticals ... (NASDAQ: BIND ). Learn more about these stocks ...
(Date:6/23/2016)... ... June 23, 2016 , ... ... of intelligent tools designed, tuned and optimized exclusively for Okuma CNC machining centers ... The result of a collaboration among several companies with expertise in toolholding, cutting ...
(Date:6/22/2016)... , June 22, 2016 Cell Applications, ... allow them to produce up to one billion ... lot within one week. These high-quality, consistent stem ... preparing cells and spend more time doing meaningful, ... a proprietary, high-volume manufacturing process that produces affordable, ...
Breaking Biology Technology:
(Date:4/28/2016)... BANGALORE, India , April 28, 2016 /PRNewswire/ ... product subsidiary of Infosys (NYSE: INFY ), and ... global partnership that will provide end customers with ... banking and payment services.      (Logo: http://photos.prnewswire.com/prnh/20130122/589162 ... area for financial services, but it also plays a fundamental ...
(Date:4/19/2016)... The new GEZE SecuLogic access ... "all-in-one" system solution for all door components. It can ... door interface with integration authorization management system, and thus ... minimal dimensions of the access control and the optimum ... offer considerable freedom of design with regard to the ...
(Date:4/13/2016)... , April 13, 2016  IMPOWER physicians supporting Medicaid ... setting a new clinical standard in telehealth thanks to ... leveraging the higi platform, IMPOWER patients can routinely track ... and body mass index, and, when they opt in, ... convenient visit to a local retail location at no ...
Breaking Biology News(10 mins):