Late last year as part of our GE Genius Series, we were introduced to Radislav Potyrailo and his team’s startling work on the chemical sensing properties found in the nanostructures of butterfly wings. A principal scientist at GE Global Research’s Chemical and Biological Sensing Laboratory in upstate New York, Radislav’s goal is to replicate those nanostructures, which change color in the presence of different compounds, to create sensors that would enable highly selective, near-instantaneous detection of chemical threats. As just reported, that work has now drawn the attention of DARPA — the top government research agency that was founded in response to the surprise launch of Sputnik in 1958 and was instrumental in the creation of the Internet. The agency has now awarded a $6.3 million grant to develop new bio-inspired nanostructured sensors that would enable faster, more selective detection of dangerous warfare agents and explosives. As Radislav writes on the GE Global Research blog today, even though there continues to be great leaps in miniaturizing sensors using traditional detection methods, the new direction being pursued now can fundamentally change the entire chemical detection process. “Our DARPA-funded program will detonate this status quo,” he writes.
 Mood wing: Here you can see the color changes of a Morpho butterfly upon exposure to different liquids. On the left is a butterfly before exposure to liquids and on the right is one exposed to ethanol on the left forewing and toluene on the left hindwing. |
At the heart of the project is the way in which butterfly wings change color. As Wired’s UK edition explains: “The nanostructures of the iridescent scales of a butterfly’s wing are strongly influenced by the surrounding gas environment, meaning that it gives different optical responses when it comes into contact with different vapors, dramatically outperforming existing nano-engineered sensors.” They add that “the sensors could have a very straightforward color-sensitive readout that would replace current complicated sensor arrays.”
And while DARPA’s interest is in saving lives in the event of a chemical or biological attack, the butterfly breakthrough could also be used in a wide range of practical, civilian uses, such as monitoring power plant emissions, water quality, food safety, and in detecting diseases at early stages by analyzing the chemical compounds in a person’s breath.
As Popular Science notes about the ultra-tiny sensors, which would be one centimeter square in size and could be made cheaply and in large volumes: “Such sensors could be embedded in clothing and designed to change color if they detect a chemical or biological threat, or they could be spread out over a large region like confetti to help the military identify areas where certain substances non grata might be hiding or lingering.”
Radislav told the U.S. edition of Wired: “It would be science fiction to say ‘here is my sensor, it can selectively detect 1,000 different chemicals.’ But what we’re saying is that we can detect and distinguish between several important chemicals — without making mistakes, without false responses.”
 Pretty complex: About three years ago, GE scientists discovered that the nanostructures on the wing scales of Morpho butterflies have acute chemical sensing capabilities. DARPA Program Manager Viktoria Greanya, Ph.D., said: “We have been greatly inspired by examples of naturally occurring optical structures…. For example, the brilliant colors seen in butterfly wings, beetle carapaces, and peacock feathers are due in large part to their complex structure, not simply their color. DARPA’s goal in this program is to harness the best of nature’s own photonic structures” and combine it with “advances in materials technology.” |
As the editors at TechCrunch quip about the breakthrough: “It’s a credit to scientists in general that they will always admit when nature has outdone them — usually millions or billions of years ago.”
* Watch our video with Radislav from September 2009
* Read the announcement
* Read ““Wearable airborne chemical sensor wins NIH award” on GE Reports
* Read additional coverage by Bloomberg Newswire, Engadget, Ubergizmo, Albany Times Union, Smart Planet, Genetic Engineering News, Hartford Courant, Homeland Security Newswire
