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Nanotech cloaking device reveals all - and nothing

posted 3 Oct 2011, 16:41 by Mpelembe   [ updated 3 Oct 2011, 16:44 ]

Scientists from the University of Dallas, Texas have used nanotechnology to create a cloaking device that replicates the mirage-effect seen in deserts and on long roads. The device presents new options for making objects disappear from view, clearly demonstrated in a short video produced by the researchers.

DALLAS, TEXAS, UNITED STATES UNIVERSITY OF DALLAS - It could become the next big thing in espionage - an invisibility cloak that mimics the natural phenomenon of the mirage-effect.

The design, by Universty of Dallas scientists, makes use of sheets of carbon nanotubes (CNT) - one-molecule-thick sheets of carbon wrapped up into cylindrical tubes. CNTs have the density of air but the strength of steel, but it is their exceptional ability to conduct and transfer heat to surrounding areas that makes them ideal for recreating mirages at will.

The mirage effect, frequently observed in deserts or on long roads in the summer, is an optical phenomenon in which light rays are bent to produce a displaced image of distant objects or the sky. Differences in temperature between air at ground level and air higher up, causes light rays to bend upward towards the viewer's eye rather than bounce off the

surface. The resulting effect is often an image of the sky appearing on the ground which the viewer perceives as water actually reflecting the sky.

The scientists discovered that through electrical stimulation, a transparent sheet of strategically aligned CNTs can be easily heated to high temperatures. They then have the ability to transfer that heat to the surrounding area, causing a steep temperature gradient. Just like a mirage, this steep temperature gradient causes the light rays to bend away from the object concealed behind the device, making it appear invisible.

The experiment was described in detail in a paper published in IOP Publishing's journal, Nanotechnology

The scientists, led by lead author Dr Ali Aliev, say the device works particularly well under water. They say it is the ease with which the CNTs can be heated that gives the device its unique 'on and off' feature.

For the world's spy agencies, the technology could be a boon although its full range of practical applications remains to be seen.