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Gas released from your body could very well provide health data through a wearable in the future. No, not that kind of body gas. A new study out of Ohio State suggests that gasses released through a person’s skin can be used to detect a range of biomarkers, such as those signaling heart disease, diabetes, metabolic disorders, and more. While most of today’s health-monitoring wearables rely on reflected light or the body’s electrical signals to detect and measure biomarkers, this kind of sensor takes a reading of emissions, including gaseous acetone that human skin releases. 

A person’s acetone level offers a window into their health. For example, the human body produces acetone as it breaks down fat. And if you are on a low-fat diet, there will be more acetone in your system, as your body will make acetone from body fat. The acetone in one’s breath can be used to measure a person’s blood-sugar level and fat-burning rate. If this technology sounds familiar, you’re right, and may be thinking of a breathalyzer test. It uses similar technology to measure the amount of alcohol in a person’s blood and detect viruses. 

Ohio State researchers set out to see if they could detect chemicals that signal the presence of gaseous molecules; they made a film from electroactive polymers and plant-cellulose derivatives that bends in response to how much acetone it detects. To test this film, they placed it over solutions with ethanol, acetone, and water, watching for selectivity, sensitivity, and repeatability. The result? Researcher Anthony Annerino says, “We found significant bias toward bending more upon exposure to certain chemicals over others.” This bending is fast — milliseconds fast — and so the research team turned to complex algorithms and machine learning to track how the film bends in response to different agents. 

While similar sweat-sensing smart wearables exist, measuring things like sweat rates, metabolites, and electrolytes in perspiration, the wearer has to get quite sweaty to take accurate measurements. Here, the research team says it envisions a wearable with a small sensor that the user would wear in low-sweat locations on their bodies such as behind their ears or on their nails. Researcher Pelagia-Iren Gouma, professor of materials science and engineering, says, “The project still has a couple of years to go…. We are developing a new generation of skin sensors, and it will really be the new norm.”