Electronics get some skin in the game
New heat sensitive 'skin' could enable lightweight night-vision glasses
ONE day, an ordinary pair of spectacles might offer the wearer night-vision capabilities thanks to an ultra-thin electronic skin; dare we go full sci-fi and suggest the same for contacts?
That last one may be a little far-stretched, but you never know. As it is, the breakthrough is said to offer the potential for whole new classes of electronic devices and wearable sensors.
Engineers at the Massachusetts Institute of Technology (MIT) have developed a technique to grow and peel ultra-thin 'skins' of electronic material that can sense heat and other signals.
Beyond night-vision glasses and other compact imaging device, the researchers suggest the method could be used to fabricate flexible transistors and computing elements.
To demonstrate their technique, the team fabricated a thin membrane of pyroelectric material, which produces an electric current in response to changes in temperature. Apparently, the thinner it is, the better it is at sensing subtle thermal variations.
In this instance, they created a membrane measuring 10 nanometers thick; the thinnest yet. This demonstrated that the film is highly sensitive to heat and radiation across the far-infrared spectrum.
According to the team, the newly developed film could enable lighter, more portable, and highly accurate far-infrared (IR) sensing devices, with potential applications for night-vision eyewear and autonomous driving in foggy conditions.
Current state-of-the-art far-IR sensors require bulky cooling elements. In contrast, the new pyroelectric thin film requires no cooling and is sensitive to much smaller changes in temperature.
The heat-sensing film could also have applications in environmental and biological sensing, as well as imaging of astrophysical phenomena that emit far-infrared radiation.
The researchers say they are exploring ways to incorporate the film into lighter, higher-precision night-vision glasses.
“This film considerably reduces weight and cost, making it lightweight, portable, and easier to integrate,” said Xinyuan Zhang, a graduate student in MIT’s Department of Materials Science & Engineering (DMSE). “For example, it could be directly worn on glasses.”
Zhang is first author of the paper exploring the results of the team's study, published in the journal, Nature.
Current night-vision goggles and scopes are heavy and bulky. With the team new pyroelectric-based approach, devices could have the same sensitivity without the cooling weight.
The researchers also found that the films were sensitive beyond the range of current night-vision devices and could respond to wavelengths across the entire infrared spectrum. This suggests that the films could be incorporated into small, lightweight, and portable devices for various applications that require different infrared regions.
For instance, the team suggests when integrated into autonomous vehicles, the films could enable cars to 'see' pedestrians and vehicles in complete darkness or in foggy and rainy conditions.
The film could also be used in gas sensors for real-time and on-site environmental monitoring, helping detect pollutants. In electronics, they could monitor heat changes in semiconductor chips to catch early signs of malfunctioning elements.
MC