A team of researchers has developed a smart wristband that tracks human stress levels in real time by analysing sweat and heart rate simultaneously, potentially offering a solution to the global burnout epidemic.
Engineers at the University of California, Irvine (UC Irvine) unveiled the device in a study published in Nature Communications. Unlike current commercial trackers that rely solely on heart rate or skin temperature, this new system — dubbed the “Smart Quantitative and Comprehensive Stress Assessor and Sub-Classifier” (SQC-SAS) — measures the stress hormone cortisol directly from the skin.
By combining this molecular data with traditional physiological signals like heart rate and galvanic skin response, the device uses artificial intelligence to create a precise, continuous profile of the wearer’s mental state.
“Stress is not a single signal; it’s a dynamic physiological and biochemical response,” says Rahim Esfandyar-pour, senior author and assistant professor at UC Irvine. “By measuring both molecular biomarkers and physiological signals at the same time, we can reduce ambiguity and move toward stress monitoring that’s more specific, objective and informative.”
Reducing false alarms
The researchers argue that existing methods for measuring stress are fundamentally flawed. Clinical cortisol tests are invasive, expensive, and provide only a single snapshot in time. Meanwhile, consumer wearables (such as smartwatches) often produce false positives because factors like vigorous exercise, diet, environmental temperature, or even natural circadian rhythms can mimic physiological signs of stress.
The SQC-SAS solves this by cross-referencing data. It features a dual-patch system: one section tracks physical signs such as skin conductance, while the other patch analyses sweat for cortisol levels. The device is wireless and battery-free, making it significantly lighter than current market options.
“Measurements of stress obtained by electrocardiograms… lack specificity,” Esfandyar-pour explains. “Our wireless, battery-free and automated SQC-SAS is designed to be worn and measures both physiological and molecular signals, so the results paint a much more accurate picture.”
A silent epidemic
The development addresses a critical gap in preventative healthcare. Recent data suggests that 52 per cent of Americans experience overwhelming stress at least once a year. Chronic stress is a known precursor to severe conditions, including anxiety, depression, cardiovascular disease, and obesity.
Because the new device operates continuously without requiring medical personnel, it could help individuals identify triggers in their daily lives that they might otherwise miss.
“We developed this stress-monitoring wearable bioelectronic to be as user-friendly and noninvasive as possible,” says Esfandyar-pour. “People wearing it will hardly notice it’s there.”
