Hidden Assets

What do Star Trek fans have in common with the followers of Harry Potter’s adventures? The answer is that both have seen the tactical advantages of cloaking devices. Whether it’s the Klingon warship cloaking system (many Trekkies would say that the Romulans invented it first) or HP’s invisibility cloak, this science-fiction idea has recently come a step closer to reality…. although, to be fair, it’s still a long way off.

What has happened is that a group of British and U.S. scientists have successfully tested a cloaking device in a laboratory at Duke University, North Carolina. In the test, they were able to hide a small copper cylinder.

How does it work? Microwaves are deflected around the surface of an object and then regenerated on the other side. To accomplish this, a cloaking device made of 10 fibreglass rings covered with copper elements called metamaterial was used to change the direction of electromagnetic waves. The metamaterial cloak channeled the microwaves around the object like water flows around a rock.

Like visible light, microwaves bounce off objects, making them apparent and creating shadows. Of course, at microwave frequencies, the detection has to be made by instruments rather than by eye.

What the scientists did was to measure microwaves travelling across a plane of view with no obstacles. Next, they placed a copper cylinder in the same plane and measured the disturbance of the microwaves. Then the researchers placed the invisibility cloak over the copper cylinder. The cloak didn’t completely iron out the disturbance, but it greatly reduced the microwaves being blocked or deflected.

Now here’s the point that will get the military very excited. Quite simply, if an object can be hidden from microwaves, it can be hidden from radar. But I suspect the military will have to wait patiently for a truly practical cloaking system. The production of suitable metamaterials will have to employ nanotechnology manufacturing techniques, which are still in their infancy. Soooo, making those unmanned military vehicles disappear will still take some time yet. Watch this space for updates!

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