Ever
notice how the surface of a soap bubble or the inside of a seashell
changes color depending on the angle of the light? It’s a phenomenon
called iridescence. Scientists at GE Global Research have been studying
the iridescence of Morpho butterfly wings, hoping to find 21st century applications inspired by the five-million-year-old natural technology.
This month they announced that by combining those iridescent properties of Morpho
wings with more recent nanotechnology, they have created what could
become the next generation of thermal imaging sensors, the heat
detection tech used in night vision goggles, advanced medical diagnostic
devices and surveillance cameras, to name just a few examples. The
butterfly-powered breakthrough could mean cheaper thermal sensors with
higher sensitivity and faster response times.
It’s
the latest achievement for GE’s photonics program, which works with
applications involving light. And another one based on biomimicry, which
looks to nature and natural processes for technological inspiration
(for example, computer scientists have learned a great deal about
improving network security by studying the patterns of bees in a hive).
In 2010, GE’s discoveries related to the chemical sensing capabilities of tiny structures on the Morpho
wings called nanostructures caught the attention of DARPA, the
Pentagon’s innovation lab. DARPA awarded the photonics team a four-year,
$6.3 million grant to develop better sensors for detecting dangerous
warfare agents and explosives.
While
that project continues, this month’s announcement could have even wider
application for thermal imaging, where the visual heat maps of the
imaged areas can relay important information from inside the body, in a
dark setting or any other environment being monitored, in medical,
security, firefighting or military contexts.
“This
new class of thermal imaging sensors promises significant improvements
over existing detectors in their image quality, speed, sensitivity,
size, power requirements and cost,” said Dr. Radislav Potyrailo, the GE
Global Research Principal Scientist who leads the photonics program.
Dr. Potyrailo and his team recently published their findings in Nature Photonics. They found that when infrared radiation hit the Morpho
butterfly wing, the nanostructures on the wing heat up and expand,
causing the color change, or iridescence. Using nanotechnology to add
tiny nanotubes to the wings, the scientists were able to increase the
amount of radiation the wings can absorb, improving their sensitivity.
Towards high-speed imaging of infrared photons with bio-inspired nanoarchitectures
