Invisibility cloak moving closer into view?
That cloaking device we've been dreaming of appears to be one step closer to actual cloakdom, so start pondering the mischievous possibilities.
Scientists from Duke University have improved on their earlier efforts at producing an invisibility cloak, coming up with a new type of device they say is significantly more sophisticated at cloaking an object (and eventually a person?) from visible light.
The device is made from a light-bending composite material that can detour electromagnetic waves around an object and reconnect them on the other side. That creates an effect similar to a distant mirage you'd see hovering above a road on a hot day.
In Duke's latest experiments, a beam of microwaves aimed through the cloaking device at a "bump" on a flat mirror surface bounced off the surface at the same angle, as if the bump wasn't there. Additionally, the device prevented the formation of scattered beams that would normally be expected from such a perturbation. (The team details its findings in far more technical terms than I ever could in the latest issue of Science magazine.)
"The difference between the original device and the latest model is like night and day," said David R. Smith, a professor of electrical and computer engineering at Duke, and the senior member of the research team. "The new device can cloak a much wider spectrum of waves--nearly limitless--and will scale far more easily to infrared and visible light. The approach we used should help us expand and improve our abilities to cloak different types of waves."
The newest cloak measures 20 inches by 4 inches and is less than an inch high. It's composed up of thousands of individual pieces of so-called metamaterials, made of the fiberglass material used in circuit boards and etched with copper.
It took nine days to get the latest device from conception to fabrication, compared with the four months it took to create the original device. Suddenly, we're imagining cloak companies springing up everywhere.
Smith envisions many possible applications for the devices. By eliminating obstructions, they could improve wireless communications, he said, or acoustic cloaks could serve as protective shields, preventing the penetration of vibrations, sound, or seismic waves.