Tunable Materials Clear the Way for Advanced Optics

Estimated reading time: 3 minutes

The researchers successfully tuned the transition for the material across a variety of specific temperatures — ranging from typical indoor comfort to medium-rare hamburger.

“Objects designed to emit light efficiently at high temperatures but not at low temperatures could be used as purely passive temperature regulators that don’t require external circuitry or power sources,” says Kats.

Materials with this unprecedented versatility could also create new types of thermal camouflage.

“Structures designed to emit the same amount of thermal radiation no matter the temperature could be used to hide objects from infrared cameras,” says Kats.

Previously, researchers attempting to change the transition temperatures of vanadium dioxide introduced impurities while trying to uniformly alter the material’s entire surface.

Instead, Kats and colleagues bombarded specific regions of the vanadium dioxide with energetic ions. Ion irradiation creates defects in materials, usually an unintended side effect. However, collaborator Carsten Ronning, a professor of solid state physics at the Friedrich Schiller University of Jena in Germany, says the researchers’ advance capitalizes on those defects.

“The beauty in our approach is that we take advantage of the ‘unwanted’ defects,” he says.

Directing the ion beam at specific regions of a surface allowed the researchers to make nanoscale modifications to the material.

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