INVISIBILITY 21
METAMATERIALS AND
INVISIBILITY
But perhaps the most promising new development involving invisibility is an exotic new material called a "metamaterial," which may one
day render objects truly invisible. Ironically, the creation of metamaterials was once thought to be impossible because they violated the
laws of optics. But in 2006 researchers at Duke University in Durham,
North Carolina, and Imperial College in London successfully defied
conventional wisdom and used metamaterials to make an object invisible to microwave radiation. Although there are still many hurdles to
overcome, for the first time in history we now have a blueprint to render ordinary objects invisible. (The Pentagon's Defense Advanced Research Projects Agency [DARPA] funded this research.)
Nathan Myhrvold, former chief technology officer at Microsoft,
says the revolutionary potential of metamaterials "will completely
change the way we approach optics and nearly every aspect of electronics ... Some of these metamaterials can perform feats that would
have seemed miraculous a few decades ago."
What are these metamaterials? They are substances that have optical properties not found in nature. Metamaterials are created by embedding tiny implants within a substance that force electromagnetic
waves to bend in unorthodox ways. At Duke University, scientists embedded tiny electrical circuits within copper bands that are arranged
in flat, concentric circles (somewhat resembling the coils of an electric
oven). The result was a sophisticated mixture of ceramic, Teflon, fiber
composites, and metal components. These tiny implants in the copper
make it possible to bend and channel the path of microwave radiation
in a specific way. Think about the way a river flows around a boulder.
Because the water quickly wraps around the boulder, the presence of
the boulder has been washed out downstream. Similarly, metamaterials can continuously alter and bend the path of microwaves so that
they flow around a cylinder, for example, essentially making everything inside the cylinder invisible to microwaves. If the metamaterial
can eliminate all reflection and shadows, then it can render an object
totally invisible to that form of radiation.
METAMATERIALS AND
INVISIBILITY
But perhaps the most promising new development involving invisibility is an exotic new material called a "metamaterial," which may one
day render objects truly invisible. Ironically, the creation of metamaterials was once thought to be impossible because they violated the
laws of optics. But in 2006 researchers at Duke University in Durham,
North Carolina, and Imperial College in London successfully defied
conventional wisdom and used metamaterials to make an object invisible to microwave radiation. Although there are still many hurdles to
overcome, for the first time in history we now have a blueprint to render ordinary objects invisible. (The Pentagon's Defense Advanced Research Projects Agency [DARPA] funded this research.)
Nathan Myhrvold, former chief technology officer at Microsoft,
says the revolutionary potential of metamaterials "will completely
change the way we approach optics and nearly every aspect of electronics ... Some of these metamaterials can perform feats that would
have seemed miraculous a few decades ago."
What are these metamaterials? They are substances that have optical properties not found in nature. Metamaterials are created by embedding tiny implants within a substance that force electromagnetic
waves to bend in unorthodox ways. At Duke University, scientists embedded tiny electrical circuits within copper bands that are arranged
in flat, concentric circles (somewhat resembling the coils of an electric
oven). The result was a sophisticated mixture of ceramic, Teflon, fiber
composites, and metal components. These tiny implants in the copper
make it possible to bend and channel the path of microwave radiation
in a specific way. Think about the way a river flows around a boulder.
Because the water quickly wraps around the boulder, the presence of
the boulder has been washed out downstream. Similarly, metamaterials can continuously alter and bend the path of microwaves so that
they flow around a cylinder, for example, essentially making everything inside the cylinder invisible to microwaves. If the metamaterial
can eliminate all reflection and shadows, then it can render an object
totally invisible to that form of radiation.