Researchers in Korea have developed a low cost thermal sensor that can be used for driverless cars and possibly smartphones.
The team led by Dr. Won Jun Choi at the Center for Opto-Electronic Materials and Devices in the Korea Institute of Science and Technology (KIST) developed a device using a vanadium dioxide (VO2)-B film that is stable at 100 °C. This device detects and converts the infrared light generated by heat into electrical signals. This eliminates the need for cooling devices, which account for over 10 percent of the cost of thermal-imaging sensors and consume large amounts of electricity.
Working with the team of Prof. Jeong Min Baik from Sungkyunkwan University (SKKU), the sensor developed in this work can operate at temperatures up to 100 °C without a cooling device and is expected to be more affordable than standard sensors on the market, which pave the way for its application to smartphones and autonomous vehicles.
The device was able to obtain the same level of infrared signals at 100 °C as at room temperature. Using an infrared absorber that can absorb as much external infrared light as possible, heat signatures were detected with three times more sensitivity and converted into electrical signals.
The device shows around 3 milliseconds of response time even at 100 °C, which is three times faster than conventional sensors. Such high response speeds enable the device to capture thermal images at 100 frames per second, far exceeding the conventional level of 30-40 frames per second. This makes the device an interesting candidate for use in autonomous vehicles, as well.
"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. 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,"