Nanoscale device turns light to mechanical action

It is claimed the development could lead to more sensitive infrared cameras and more compact chemical-analysis techniques.

The research, published in Nano Letters, was conducted by assistant professor Ertugrul Cubukcu and postdoctoral researcher Fei Yi, along with graduate students Hai Zhu and Jason C. Reed, all of the Department of Material Science and Engineering in Penn’s School of Engineering and Applied Science.  

Detecting light in the mid-infrared range is important for applications like night-vision cameras, but it can also be used to perform spectroscopy, a technique that scatters light over a substance to infer its chemical composition.

Existing infrared detectors use cryogenically cooled semiconductors, or thermal detectors known as microbolometers, in which changes in electrical resistance can be correlated to temperatures. These techniques have their own advantages, but both need expensive, bulky equipment to be sensitive enough for spectroscopy applications.

‘We set out to make an optomechanical thermal infrared detector,’ Cubukcu said in a statement. ‘Rather than changes in resistance, our detector works by connecting mechanical motion to changes in temperature.’