KAIST Develops Low-Power, High-Speed Wearable Carbon Dioxide Sensor

2025-02-28

Professor Seung-hyeop Yoo’s team of the Department of Electrical Engineering at KAIST has developed a low-power, high-speed wearable carbon dioxide sensor that can monitor breathing stably in real time.

Existing non-invasive carbon dioxide sensors are bulky and consume high power. In addition, while photochemical carbon dioxide sensors can be miniaturized and made lightweight, they have limitations for use as wearable healthcare sensors due to the photodegradation of the dye molecules used.

The research team developed a low-power carbon dioxide sensor composed of an LED and an organic photodiode that surrounds it. The newly developed sensor has a device power consumption of 171 μW, which is tens of times lower than the existing one, as the amount of excitation light irradiated to the fluorescent molecules is minimized. In addition, the research team identified the photodegradation pathway of the fluorescent molecules used in the carbon dioxide sensor and presented an optical design method to suppress the occurrence of errors over time in the use of photochemical sensors.

As a result, the research team reduced the occurrence of errors due to the photodegradation phenomenon and extended the stable continuous use time from within 20 minutes to a maximum of 9 hours. The sensor developed is light (0.12g), thin (0.7mm), and flexible, and successfully measured the carbon dioxide concentration by being attached to the inside of the mask. In addition, this sensor showed high speed and high resolution capable of monitoring the respiratory rate by distinguishing between inhalation and exhalation in real time.

Source: https://news.nate.com/view/20250210n14409