Sweat Sensor Image
A hand-held device combined with a touch sweat sensor (strip at right) measures glucose in sweat, while a personalized algorithm converts that data into a blood glucose level. (Credit: Adapted from ACS Sensors 2021, DOI: 10.1021/acssensors.1c00139)

Researchers have developed a device that can measure glucose in sweat with the touch of a fingertip, and then a personalized algorithm provides an accurate estimate of blood glucose levels.

The researchers made a touch-based sweat glucose sensor with a polyvinyl alcohol hydrogel on top of an electrochemical sensor, which was screen-printed onto a flexible plastic strip. When a volunteer placed their fingertip on the sensor surface for 1 minute, the hydrogel absorbed tiny amounts of sweat. Inside the sensor, glucose in the sweat underwent an enzymatic reaction that resulted in a small electrical current that was detected by a hand-held device.

They also measured the volunteers’ blood sugar with a standard finger-prick test, and they developed a personalized algorithm that could translate each person’s sweat glucose to their blood glucose levels. In tests, the algorithm was more than 95 percent accurate in predicting blood glucose levels before and after meals.

To calibrate the device, a person with diabetes would need a finger prick only once or twice per month. But before the sweat diagnostic can be used to manage diabetes, a large-scale study must be conducted, the researchers say.