David Kirkpatrick

July 16, 2008

The Casimir force and nanotechnology

Filed under: Science, Technology — Tags: , , , , — David Kirkpatrick @ 12:54 am

I first blogged on the Casimir force, stiction and nanotech a couple of weeks ago (find that post here and check out the first item) Here’s some updated news out of the University of Florida. Physicists there have found a way to reduce quantum stickiness.

From the second link:

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 physicistshave 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.

June 30, 2008

Quantum stickiness, Hawking and teh funny

From KurzweilAI.net, micromachine stiction, Stephen Hawking tackles the universe’s inflation and defining humor.

How a quantum effect is gumming up nanomachines
New Scientist news service, June 28, 2008

Researchers are making progress in overcoming static friction, or or “stiction,” which sticks together the parts of micromachines on scales of between 10 and 300 nanometers and limits progress in reducing their size, affecting computer hard drives and other devices with small moving parts.

Stiction is due to the Casimir effect, a quantum-mechanics phenomenon that causes surfaces to be attracted. Methods to reduce its effect include use of patterned surfaces, suspending the components in a liquid, and use of metamaterials.

 
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Hawking ‘close’ to explaining universe’s inflation
New Scientist (article preview), June 28, 2008

Starting with current observations of the universe and working back to narrow down the initial set of possibilities and by treating the early cosmos as a quantum object with a multitude of alternative universes that gradually blend into ours, Stephen Hawking and colleagues think they are close to perfecting an answer to explain why the infant universe expanded so rapidly.

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Mechanism and function of humor identified by new evolutionary theory
PhysOrg.com, June 27, 2008

Humor occurs when the brain recognizes a pattern that surprises it, suggests Alastair Clarke in the forthcoming book, Humour.

“Now that we understand the mechanism of humour, the possibility of creating an artificial intelligence being that could develop its own sense of humour becomes very real,” he says. “This would, for the first time, create an AI capable of exhibiting one of the defining characteristics that make us human, making it seem significantly less robotic as a result.”

 
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