Metamaterial Electromagnetic Cloak at Microwave Frequencies

AI Thread Summary
Duke University researchers have made progress toward invisibility through the development of a metamaterial electromagnetic cloak that operates at microwave frequencies. This technology utilizes concentric copper circles on a fiberglass board to deflect electromagnetic waves, allowing them to flow around the structure without significant scattering or absorption, akin to water flowing around a rock. David R. Smith, a professor involved in the study, explains that this method minimizes reflections and shadows. The discussion also touches on the concept of negative refractive index in metamaterials, which could potentially allow light to bend in unconventional ways. However, achieving similar effects with visible light requires more precise control over the metamaterial's structure. Additional resources and links are provided for further exploration of metamaterials and their applications.
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If you happen to see microwaves...

Scientists Take Step Toward Invisibility

...team at Duke University have demonstrated a technology that could be a small step in the right misdirection.

Metamaterial Electromagnetic Cloak at Microwave Frequencies (Science)
David R. Smith's Web Site The system, a set of concentric copper circles on fiberglass board, deflects electromagnetic waves of a specific frequency that strike it, without much of the scattering and absorption that make reflections and shadows.

A result is that the microwaves slide around the structure like water flowing around a smooth rock in a stream, said David R. Smith, a professor of electrical and computer engineering at Duke and an author of the paper published today in the journal Science. [continued]
http://www.nytimes.com/2006/10/20/s...&en=cd2cdec26f18ae3a&ei=5094&partner=homepage

See also:
http://www.ee.duke.edu/~drsmith/cloaking.html
 
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Ooooh, Sweet :D
 
Yeah I must say this is extremely interesting.
Now I must google for morei nformation on these 'metamaterials.'
 
Octelcogopod is this like you're first post outside the philosophy forums? :-pEdit: Okay I looked up metamaterials too.. how the hell does Negative Refractive index work? Maybe my understanding of the concept is juvenile or something but would that mean light passes through the substance -more- easily then the substance it was in before it?
 
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How negative refraction works?

If you put a pen in a glass of water, you will see it appears bent due to positive refraction of the water. If water had negative refraction you would see the pen bending in the opposite direction than that of positive refraction.
 
That doesn't explain how they work, that's just explaining what they do, and I knew that part already.
 
Gelsamel Epsilon said:
That doesn't explain how they work, that's just explaining what they do, and I knew that part already.
Here's an introduction.

http://www.ee.duke.edu/~drsmith/neg_ref_home.htm

There is a pretty good Wiki article on metamaterials, too, with additional links. If they ever hope to extend the effect to visible light, they will have to control the structure of the metamaterials to much finer degrees.
 
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http://www.popsci.com/popsci/technology/b0b13ddbf6fed010vgnvcm1000004eecbccdrcrd.html
 
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Note that this is very different techology from that in the original post.
 
  • #10
http://www.st-andrews.ac.uk/~ulf/invisibility.html

For a theorist's approach.
 
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