Novel Thin-Film Thermal Camera Could Drive Down the Cost, Improve the Performance of Thermal Imaging

Scientists at Korea Institute of Science and Technology (KIST), alongside colleagues at a range of other universities and facilities in South Korea, have come up with a low-cost means to turn add thermal cameras to future smartphones for temperature-based COVID-19 screening.

Thermal imaging sensors, which turn normally-invisible infrared radiation into visible light, are a common diagnostic tool for everything from healthcare to electronics — but their widespread use is hampered by high cost. That's where Won Jun Choi, PhD, and his team come in, with a sensor designed to work in conjunction with smartphone cameras to dramatically reduce the cost of thermal imaging.

"By means of our work with convergence research in this study, we have developed a technology that could dramatically reduce the production cost of thermal-imaging sensors," Choi explains. "Our device, when compared to more conventional ones, has superior responsivity and operating speed. We expect this to accelerate the use of thermal-imaging sensors in the military supply, smartphone, and autonomous vehicle industries."

The sensor is based on a vanadium dioxide (VO₂)-B film, which remains stable at temperatures up to 100°C (212°F) — removing the need for the cooling device that makes up a chunk of the bill of materials for current thermal camera systems.

The prototype sensor proved capable of a 3ms response time, offering up to 100 frames per second of thermal data capture — far in excess of the 30-40 frames per second of more expensive sensors. This, the team propose, could extend the technology not only into future smartphones and health monitoring systems but even into performance-sensitive autonomous vehicles.

The team's work has been published under closed-access terms in the journal Applied Surface Science.