Engineering prof creates 'cloaking device'

“Invisibility cloaks” no longer only exist at Hogwarts School of Witchcraft and Wizardry.

Cloaking-device technology can now be found in the halls of the School of Engineering and Applied Science.

Electrical and Systems Engineering and Bioengineering professor Nader Engheta has created a cloaking device that makes objects “less visible” to the human eye, he said.

The device is intended to increase the accuracy of measurements.

According to Engheta, future uses include biomedical machinery and nanotechnology, as well as stealth technology for military application.

The device was first introduced and used by the Romulans in the fictional television series “Star Trek.” Its appearance — even in fiction — came as a surprise to scientists, who had only considered it a theoretical possibility.

Engheta’s research team worked with nanoparticles of metals like gold and silver. Also known as metamaterials, the particles bend light around objects.

“When a light wave hits an object, it scatters, and it is this scattering that causes us to see the object,” Engheta explained. “The technique that we worked with is called the ‘scattering cancellation’ method because the cloaking device we place around the object causes two scatterings, which then cancel each other out.”

As a result, “the goal of a cloak is to reduce this scattering and absorption so that the light moves around or through it in such a way as to convince the observer that it isn’t there at all,” said Brian Edwards, a post-doctorate Engineering researcher and a member of Engheta’s research team.

Theorists on the team have published papers on possible ways to create the device.

Edwards’ job was to take these ideas and “render them into something tangible and measure the electromagnetic waves to verify that the object was indeed cloaked,” Edwards explained.

The structure he created was designed to hide a piece of plastic from microwaves, or electromagnetic waves.

Before the cloak was dimantled last week, it consisted of metallic fins surrounded by a fluid that can store high amounts of electrical energy.

“If everything is working the way it should, the fields surrounding the cloaked object look a lot like the fields when nothing was there at all,” said Edwards.

However, “just as with everything else, there are limitations,” said Engheta. “But we have made enough progress to make scientific measurement more accurate.”

Probes covered with the cloaking device can now measure light more accurately. Any optical sensor will inevitably distort the light, causing an error in measurement. A cloaked sensor would reduce this effect so that it is less likely that the results of measurements are distorted by the measurement probe.

“It would be a very bad ruler that, when placed near an object, magically makes the object three inches instead of its natural four inches,” said Edwards. This technology would reduce such errors.

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