A research team lead by Dr. Won Jun Choi at the Center for Opto-Electronic Materials and Devices in the Korea Institute of Science and Technology (KIST) has announced the development of a thermal-imaging sensor that overcomes the existing problems of price and operating-temperature limitations through convergence research with the team of Prof. Jeong Min Baik from Sungkyunkwan University (SKKU). The sensor developed by the researchers 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 would in turn pave the way for its application to smartphones and autonomous vehicles.
Thermal-imaging sensors that detect and capture images of the heat signatures of human bodies and other objects have recently sprung into use in thermostats to check facial temperatures in a contactless attempt to screen for COVID-19 at several building entrances. Under these circumstances, the smartphone industry is actively considering the incorporation of such sensors as portable features to create the add-on function of measuring temperature in real time. Additionally, the application of such technology to autonomous vehicles may facilitate safer autonomous driving.
To be integrated with the hardware of smartphones and autonomous vehicles, sensors must operate stably without any difficulties at high temperatures of 85 °C and 125 °C, respectively. For conventional thermal-imaging sensors to meet this criterion, an independent cooling device would be required. However, high-end cooling devices that promise quality are expensive. Further, such devices do not make the sensor suitable for operations at temperatures as high as 85 °C. Therefore, conventional thermal-imaging sensors have not been applied in these fields.
A joint research team from KIST and SKKU has 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% of the cost of thermal-imaging sensors and consume large amounts of electricity. The device was able to obtain the same level of infrared signals at 100 °C as at room temperature.