Wearable Biosensor Detects Stress from Sweat
By drawing in a bit of sweat, a patch developed in the lab of Alberto Salleo can reveal how much cortisol a person is producing. Cortisol is known as the stress hormone but is involved in many important physiological functions.
The hormone cortisol rises and falls naturally throughout the day and can spike in response to stress but current methods for measuring cortisol levels require waiting several days for results from a lab. By the time a person learns the results of a cortisol test – which may inform treatment for certain medical conditions – it is likely different from the current level of cortisol.
Now, a group led by materials scientist Alberto Salleo at Stanford University has created a stretchy patch that, applied directly to the skin, wicks up sweat and assesses how much cortisol a person is producing. A paper about the wearable sensor was published July 20 in Science Advances.
“We are particularly interested in sweat sensing, because it offers noninvasive and continuous monitoring of various biomarkers for a range of physiological conditions,” said Onur Parlak, a post-doctoral scholar in the Salleo lab and lead author of the paper. “This offers a novel approach for the early detection of various diseases and evaluation of sports performance.”
Clinical tests that measure cortisol provide an objective gauge of emotional or physical stress in research subjects and can help doctors tell if a patient’s adrenal or pituitary gland is working properly. If the prototype version of the wearable device becomes a reality, it could allow people with an imbalance to monitor their own levels at home.
A fast-working test like this could also reveal the emotional state of young – even non-verbal – children, who might not otherwise be able to communicate that they feel stress.