CARES: Wearable electronic skin device to monitor nine markers of stress

The wearable electronic skin is devised to monitor nine different markers that characterize a stress response continuously. 

According to a statement by the university, CARES integrates sweat sensors with sensors that record pulse waveforms, skin temperature, and galvanic skin response. 

The device utilizes new materials for improved stability and incorporates machine learning to interpret complex physiological and chemical stress-related data.

Nevertheless, stress induces a combination of physiological responses that, when considered collectively, can offer an objective measure of stress, not relying on self-reports. Gao is observing this array of reactions using CARES.

Sensor capable of real-time monitoring

When a person is under stress, hormones like epinephrine, norepinephrine, and cortisol are released into the bloodstream," explained Gao. "Sweat becomes rich with metabolites like glucose, lactate, and uric acid, and electrolytes like sodium, potassium, and ammonium. These are substances we have measured before using microfluidic sampling on a wearable sweat sensor." 

"What is new in CARES is that sweat sensors are integrated with sensors that record pulse waveforms, skin temperature, and galvanic skin response: physiological signals that also indicate stress in predictable ways."

The research aims to provide a wearable sensor capable of real-time monitoring of stress levels. Stress, whether acute or chronic, can significantly impact physical and mental health. 

The device aims to offer early detection of stress severity for timely intervention, especially in demanding work environments such as those experienced by soldiers or astronauts.

The CARES device utilizes sensors that measure various physiological and chemical biomarkers in sweat, including hormones like epinephrine, norepinephrine, and cortisol, as well as metabolites like glucose, lactate, uric acid, and electrolytes like sodium, potassium, and ammonium. 

As per the researchers, the integration of machine learning helps interpret the data accurately, providing insights into stress levels based on the interrelatedness of different biomarkers.

"Adding these new materials greatly enhances the sensor stability during long-term operation," Gao says. 

Similar to usual sweat sensors, the electronic skin is battery-powered and can wirelessly communicate via Bluetooth with a phone or computer, the statement noted. 

The study was published in the journal Nature Electronics on January 19 and can be found here.