David Kirkpatrick

August 11, 2008

Cloaking device becoming feasible?

From KurzweilAI.net — I’ve blogged on 3D cloaking devices before, very likely the previous KurzweilAI.net linked blog post from mid-May is an earlier report of this project. Both stories originate from UC Berkeley.

At any rate, here’s 3D cloaking part two:

Practical Cloaking Devices On The Horizon?
PhysOrg.com, Aug. 10, 2008University of California, Berkeley scientists have created a multilayered, “fishnet” metamaterial that unambiguously exhibits negative refractive index, allowing for invisibility in three dimensions for the first time, Nature magazine plans to report this week.

 
Read Original Article>>

 

Update — Here’s another take on this story, once again from PhysOrg. This time with pictures!

From the link:

Two breakthroughs in the development of metamaterials – composite materials with extraordinary capabilities to bend electromagnetic waves – are reported separately this week in the Aug. 13 advanced online issue of Nature, and in the Aug. 15 issue of Science.

Applications for a metamaterial entail altering how light normally behaves. In the case of invisibility cloaks or shields, the material would need to curve light waves completely around the object like a river flowing around a rock. For optical microscopes to discern individual, living viruses or DNA molecules, the resolution of the microscope must be smaller than the wavelength of light.

The common thread in such metamaterials is negative refraction. In contrast, all materials found in nature have a positive refractive index, a measure of how much electromagnetic waves are bent when moving from one medium to another.

In a classic illustration of how refraction works, the submerged part of a pole inserted into water will appear as if it is bent up towards the water’s surface. If water exhibited negative refraction, the submerged portion of the pole would instead appear to jut out from the water’s surface. Or, to give another example, a fish swimming underwater would instead appear to be moving in the air above the water’s surface

And here’s the image:

On the left is a schematic of the first 3-D "fishnet" metamaterial that can achieve a negative index of refraction at optical frequencies. On the right is a scanning electron microscope image of the fabricated structure, developed by UC Berkeley researchers. The alternating layers form small circuits that can bend light backwards. Image by Jason Valentine, UC Berkeley
On the left is a schematic of the first 3-D “fishnet” metamaterial that can achieve a negative index of refraction at optical frequencies. On the right is a scanning electron microscope image of the fabricated structure, developed by UC Berkeley researchers. The alternating layers form small circuits that can bend light backwards. Image by Jason Valentine, UC Berkeley

About these ads

2 Comments »

  1. [...] am The University of California at Berkeley is doing some interesting work in nanotechnology (such as this “cloak of invisibility”) Applied Materials, the Santa Clara-based nanotech company is making that progress easier to [...]

    Pingback by Applied Materials makes over $5M gift to UC Berkeley « David Kirkpatrick — August 13, 2008 @ 12:09 am

  2. [...] KurzweilAI.net — I’ve blogged on invisibility cloaks and their feasibility here and here. Now all that excitement may be [...]

    Pingback by Cloak of invisibility meet your master « David Kirkpatrick — September 3, 2008 @ 11:42 pm


RSS feed for comments on this post. TrackBack URI

Leave a Reply

Fill in your details below or click an icon to log in:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out / Change )

Twitter picture

You are commenting using your Twitter account. Log Out / Change )

Facebook photo

You are commenting using your Facebook account. Log Out / Change )

Google+ photo

You are commenting using your Google+ account. Log Out / Change )

Connecting to %s

The Silver is the New Black Theme Blog at WordPress.com.

Follow

Get every new post delivered to your Inbox.

Join 26 other followers

%d bloggers like this: