21.06.18

Nanolaser copies chameleon ability to change colour

chameleon

Scientists have designed a nanolaser that can change colour in the same the way that chameleons are able to change the colour of their skin. Scientists at Northwestern University believe the work could open the door for advances in flexible optical displays in smartphones and flat panel displays, wearable devices and sensors that measure strain.

“Chameleons can easily change their colours by controlling the spacing among the nanocrystals on their skin, which determines the colour we observe,” said Teri Odom, professor of chemistry in Northwestern’s Weinberg College of Arts and Sciences. “This colouring based on surface structure is chemically stable and robust.”

The research was published online in the journal Nano Letters.

The same way a chameleon controls the spacing of nanocrystals on its skin, the Northwestern team’s laser exploits periodic arrays of metal nanoparticles on a stretchable, polymer matrix. As the matrix either stretches to pull the nanoparticles farther apart or contracts to push them closer together, the wavelength emitted from the laser changes wavelength, which also changes its colour.

The resulting laser is robust, tunable, reversible and has a high sensitivity to strain. These properties are critical for applications in responsive optical displays, on-chip photonic circuits and multiplexed optical communication.