March 6, 2009 -- Call it what you will -- the world's first 3D nanoantenna or an invisibility cloak -- but a new metamaterial created by Rice University scientists could hide objects from human sight. By creating perfectly aligned dimples in a material, the scientists channeled specific wavelengths of light from many directions into one uniform direction. "This falls into the broad class of metamaterials that have useful and unusual properties, like cloaking," said Naomi Halas, Rice University scientist and co-author of a paper describing the material in Nano Letters. "In a broader picture, you could do some very interesting things with this metamaterial." The first "invisibility cloak," which hid objects from relatively long-wavelength radio waves, was created in 2006 by scientists from Duke University. Since then scientists have tried to create ever-smaller structures to manipulate ever-smaller wavelengths of light, with the goal of creating a true invisibility cloak that would hide objects in the visible spectrum of light. Related Content:
According to Halas, this is the world's first truly 3D metamaterial -- a metamaterial being something that gets its trademark properties from its structure rather than its makeup. Creating the first nanoantenna was relatively simple. Scientists started with a layer of glass. Latex or plastic nanoparticles were sprayed over the glass at random. Gold particles were evaporated onto the nanoparticles at five different angles, creating 'nanocups.' A protective layer of acrylic was then poured over the top and cured for 36 hours to form a hard slab. The nanocups are arranged in a repeating pattern, all angled in one direction. Any light that enters a nanocup is gathered and then emitted in the direction of that angle. Since no light is reflected back into an observer's eye, the nanoantenna-coated object is hidden. "Think about the retro reflectors on stop signs," said Halas. "Those are basically microspheres that direct the light from your headlights back at you. This is the opposite. This would take the light and send it in another direction, hiding the stop sign from your sight." Get More NewsMouse Cloned From Long-Frozen CellResearchers create a mouse from a long-frozen cell. Will the mammoth be next?'Bubble' Could Protect AstronautsScientists say a "bubble" around a Mars-bound spaceship could protect astronauts.Big Reduction of Snowmobiles in Yellowstone ProposedA new plan would cut snowmobile use by 40 percent in Yellowstone.Microbes: Fuel of the Future?A reddish South American microbe is literally breathing fuel, say scientists.DNA Links Remains to Steve FossetDNA tests on two bones found in California confirm they are those of Steve Fossett.Women Carry More Bacteria Than MenSome bacteria prefer women, suggests a new study. But why?Ancient 'Water Monster' Facing ExtinctionA foot-long salamander that was a key part of Aztec legend is threatened by extinction.Grand Canyon's Youth ConfirmedThe Grand Canyon is millions of years younger than previously thought, argue geologists.My Take: E-Voting Not User FriendlyOpinion: Electronic voting machines don't always capture the intent of voters.SLIDE SHOW: Landscapes of TerrorWhat makes a place feel scary? There are scientific explanations.At 40, Brain and Body SlowThe part of the brain in charge of motion starts a gradual slide in middle age.Spiders, Scorpions Among World's Oldest CreaturesMany creepy crawlies have been on Earth much longer than previously believed.Blood-Sucking Vampire Bats Sing DuetsWhite-winged vampire bats "harmonize" with separated roost mates. |
advertisement
Put Discovery News on Your Site!
|
-
our sites
-
video
mobile
-
shop
-
stay connected
-
corporate
