WASHINGTON, July 20 (Xinhua) -- Stanford scientists created a stretchy patch that can pick up sweat on the skin and assess how much cortisol a person is producing, according to a study published on Friday in the journal Science Advances.
Clinical tests that measure cortisol can provide a gauge of emotional or physical stress in research subjects and help doctors tell if a patient's adrenal or pituitary gland is working properly.
The hormone cortisol rises and falls naturally throughout the day and can spike in response to stress.
Current methods for measuring cortisol levels require waiting several days for results from a lab. If the prototype version of such a wearable device becomes a reality, it could allow people with an imbalance to monitor their own levels at home, potentially giving results in seconds.
A fast-working test may reveal the emotional state of young children, who might not otherwise be able to communicate that they feel stress, according to the study.
"This offers a novel approach for the early detection of various diseases and evaluation of sports performance," said Onur Parlak, a post-doctoral scholar in the Alberto Salleo's lab at Stanford University and lead author of the paper.
The team built a stretchy, rectangular sensor around a membrane that specifically bound only to cortisol.
The device can suck in sweat passively through holes in the bottom of the patch and the sweat pools in a reservoir, according to the study.
Charged ions like sodium or potassium in sweat can pass through the membrane unless they are blocked by cortisol.
The sensor detects the charged ions instead of the cortisol itself and on top of all this is a waterproof layer that protects the patch from contamination.
In the future, the researchers may try the sensor on saliva, which would avoid patients needing to sweat.
