Link This | Email this | Blog This | Comments (0)

Sean Snyder

On the Micro Side of Things: Metamaterials

I talked with David Smith not too long ago, from Duke University; he was sitting on a panel discussing metamaterials. I went into the discussion not knowing much about metamaterials, but I came out with sci-fi visions of the invisible Predator from the aptly named Schwarzenegger movie.

 Basically metamaterials are materials that are composed or combined in such a way to give them properties that are unlike any known, naturally occurring materials on the planet. At a nano level, the structures are arranged as circuits with precisely placed gaps or blended material compositions.

 One of the properties (here comes the Predator) is visual cloaking of the material making it appear invisible. When light waves interact with a normal material they act in a predictable way according to their refractive index, but when light waves pass through metamaterials, the waves are distorted in an unnatural way.

 The placement of the nanoscopic components that create the metamaterial are smaller than the wavelengths themselves therefore affecting the way the waves behave. As far as I understand, this process is similar to diffusion in sound waves, which makes me wonder if there could be a similar application in thin nano-built sound proofing and dispersion panels.

 Now this has only (officially) been tested with microwaves and using metamaterials to distort optical waves will be difficult if not impossible, but the idea of filtering optical waves to create invisibility is very interesting and very Sci-Fi.