New Flexible Sensor Uses Sweat to Monitor Health

Bevin Fletcher, Associate Editor

The flexible sensor developed at UC Berkeley can be made into "smart" wristbands or headbands that provide continuous, real-time analysis of the chemicals in sweat. (Credit: Photo by Wei Gao/UC Berkeley) Engineers have developed the first fully integrated sensor system that can measure metabolites and electrolytes from sweat and sync the data in real time to a smart phone. The flexible sensors and a flexible circuit board adheres to the skin and could give vital information about health, such as dehydration, fatigue, and high body temperatures.

The non-invasive sensor system, which was detailed in a paper published online Jan. 27 in Nature, could be beneficial to athletes and patients alike.

Principal investigator, Ali Javey, Ph.D., professor of electrical engineering and computer sciences at University of California, Berkeley told the New York Times [1] that while many studies have shown how and why sweat composition changes, it was not easy to measure on patients. He said the device, which can be worn as a wristband or headband, is comfortable and easy to wear.

The flexible plastic bandage that sticks to the skin with sensors collects information about body temperature as well as four parts of sweat: sodium ions, glucose sugar, potassium ions, and lactate.

“Human sweat contains physiologically rich information, thus making it an attractive body fluid for non-invasive wearable sensors,” Javey said in a prepared statement. “However, sweat is complex and it is necessary to measure multiple targets to extract meaningful information about your state of health. In this regard, we have developed a fully integrated system that simultaneously and selectively measures multiple sweat analytes, and wirelessly transmits the processed data to a smartphone. Our work presents a technology platform for sweat-based health monitors.”

Other devices monitor health habits, such as heart rate and steps taken, but this is the first to continuously track a patient’s health at a molecular level.

Researchers tested the sensor system on dozens of men and women volunteers, who ran outdoors or pedaled on stationary bicycles between a few minutes to an hour.

The NYT reported that the researchers have filed a patent application for the device.