Every time you exhale, you emit carbon dioxide. But does your body release CO2 in other ways?
Emitted CO2 provides important information about metabolism and bodily function. However, measuring exhaled gases requires a tight-fitting mask that restricts daily activities. As an alternative, a new paper in Science Advances suggests measuring carbon dioxide released from the skin instead.
To capture the very small amount of CO2 emitted from skin, the authors designed a wearable sensor that creates an isolated chamber around a small area on the forearm. To see if skin-released CO2 provides meaningful information, nine participants wore the device for 30 minutes:
- at rest
- cycling on an exercise bike
Comparing the amount of CO2 measured from a traditional breath mask to the skin-based sensor, there was a correlation between the two measurements. The skin-sensor data also correlated with the participant’s metabolic rate.
Why does this matter?
Obtaining meaningful physiological data from skin sensors could provide a new non-invasive method of monitoring metabolism. Unlike existing breath-based methods, a skin-based sensor could integrate more easily into daily life, enabling metabolism to be tracked during eating and sleeping, or for patients with breathing issues.
Read the full paper here: https://doi.org/10.1126/sciadv.aec2376 from AAAS
Seung-Rok Kim, Noelle Davis, Kalynna Tang, George A. Brooks, and Ali Javey, Skin CO2 sniffing for wearable metabolic monitoring. Sci. Adv., 2026,12, eaec2376