Stress is a rather unwelcome bedfellow in many a modern person’s life, but it’s one of those things that can often creep up on us without us realizing. A new stretchy patch aims to help us by providing an easy, wearable way of monitoring for the cortisol hormone in our sweat.
The work, which has been documented in a recently published paper from a team of Stanford University researchers, monitors our sweat for cortisol, which is known to spike in response to stress. Valuable though this is as a marker, existing methods for measuring it require lengthy testing periods in a lab, by which time the value of treating it has likely passed.
“We are particularly interested in sweat sensing, because it offers noninvasive and continuous monitoring of various biomarkers for a range of physiological conditions,” the researchers say. “This offers a novel approach for the early detection of various diseases and evaluation of sports performance.”
Clinical shortcomings
The project aims to overcome the various shortcomings in monitoring for cortisol at the moment by providing a fast, yet reliable, means of testing the stress levels of the wearer, without the wearer having to give any verbal clues as to their wellbeing.
I’ve written a few times in the past about a growing number of sensors and patches that are able to monitor our sweat for a range of things. Indeed, a Dutch team even believe that their technology can detect illness from our sweat. Cortisol has been a tougher nut to crack however as it has no charge for sensors to pick up.
To overcome this, the team developed a stretchy sensor that specifically binds to cortisol. When it’s stuck to the skin, it absorbs sweat via holes in the patch, with the sweat pooling together underneath a cortisol-sensitive membrane.
The science behind the technology is fascinating, as charged ions can easily pass through the membrane unless they’re blocked by cortisol. These ions are then what are detected by the sensor rather than the sweat itself.
The patch is connected to a device that allows the user to to see the cortisol levels in their sweat in a matter of seconds. The software side of things is fairly basic at the moment but the team hope to integrate it into a more fully fledged system in time.
It’s already achieved the gold standard clinical test standard in laboratory settings, and managed to achieve identical results in a real world test as well. The team plan to test it further however to prove its robustness, whilst also ensuring the patch is reusable. Early prototypes suggest that they’re on the right track, but there is still work to be done before it’s production ready.
