December 19, 2013
Invisibility, it is just the beginning...
Posted December 16, 2013 by Melissa Pandika
"While science has gone Hollywood with Gravity and The Big Bang Theory, Hollywood has also gone science. When Harry Potter first donned his invisibility cloak, physicists around the world famously embarked on a quest to engineer the magical fabric. But invisibility cloaks are just the beginning. Scientists are designing many other materials that are allowing them to make the leap from reel to real.
These so-called metamaterials are built from tiny metal or plastic structures arranged in precise patterns, which give them weird properties that aren’t seen in natural materials. Some metamaterials bend electromagnetic waves around objects, which can render them invisible to not only the naked eye but also to radar and sonar. Some metamaterials have unusual mechanical properties that allow them to “remember” their original shape, while others stretch when they’re compressed, and vice versa.
Invisibility cloaks have obvious military applications, but metamaterials also hold promise for drug delivery, energy-efficient power, improved cell phone signal strength and many other commercial uses. Metamaterial products could become mainstream within the decade, researchers say.
“The application of metamaterials will bring in a whole new era of next-generation materials research,” said Dan Luo, a professor of biological and environmental engineering at Cornell University.
Physicist David Smith and his colleagues at UC San Diego unveiled the first metamaterial in 2000 — an array of tiny copper wires and rings that deflected microwave beams. Since microwave scanners detect objects when microwaves bounce off them and hit the sensors, the material remained undetected by the scanner. The technology raised hopes for fabricating an invisibility cloak, since we detect objects similarly when light reflects off them and reaches our eyes.
Last November, researchers from Duke University reported designing an invisibility cloak that can hide a 7.5-centimeter cylinder, while Nanyang Technological University scientists have shielded a cat and goldfish using cloaking devices made from conventional materials rather than metamaterials. But these cloaks work only in a single 2-D plane, so the object is hidden only to those looking from a certain direction."
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