Researchers at the University of California, Irvine, have developed a multimodal, bioelectronic wrist-worn device for objective, continuous, real-time monitoring of stress.

Outlined in a paper published in Nature Communications, the wearable simultaneously tracks molecular stress biomarkers alongside physiological stress indicators, providing a complete and precise picture of how stress is experienced by humans.

Stress is widely recognised as a major contributor to mental and physical health, yet accurate measurement of it remains difficult. Many common approaches are either subjective, relying on self-reporting, or limited to one-time snapshots that fail to capture how stress changes over time.

The UC Irvine team wanted to remedy this by integrating multimodal biosensing, wireless operation and machine learning into a wearable device intended for objectiveness and ease of use.

“Stress is not a single signal; it’s a dynamic physiological and biochemical response,” said senior author Rahim Esfandyar-pour. “By measuring both molecular biomarkers and physiological signals at the same time, we can reduce ambiguity and move towards stress monitoring that’s more specific, objective and informative.”

Unlike many wearables that rely on a single physiological indicator, this is designed to collect multiple synchronised inputs through an integrated panel that pairs a physiological patch that tracks heart rate and skin conductance with a molecular patch for sweat cortisol (stress hormone) detection, along with electronics for wireless signal acquisition and recording.

To translate these multimodal biosignals into actionable insights, the researchers developed an accurate AI model.

Esfandyar-pour’s UC Irvine team emphasised that existing clinical approaches for cortisol-based stress assessment can be invasive and often require specialised medical personnel and facilities, while many physiology-based wearables can be ambiguous.

“Measurements of stress obtained by electrocardiograms or through galvanic skin response and skin temperature lack specificity, often producing false-positive or false-negative results due to confounding factors such as physical activity, diet, environmental conditions or circadian rhythms,” Esfandyar-pour said. “Our wireless, batteryfree and automated device is designed to be worn and measures both physiological and molecular signals, so the results paint a much more accurate picture of the stress people are encountering. We developed this stress-monitoring wearable bioelectronic to be as user-friendly and noninvasive as possible. People wearing it will hardly notice it’s there, while it continuously and objectively captures their stress profile.”

He said it addressed a critical healthcare gap at a time when stress had reached epidemic proportions and many were going undiagnosed and untreated. According to recent data, 52 per cent of Americans and 60 per cent of individuals across 34 countries reported facing stress so overwhelming that they struggled to manage it at least once throughout the year. Chronic stress can contribute to serious mental health disorders such as anxiety and depression, as well as physical conditions including cardiovascular disease and obesity.

Joining Esfandyar-pour on this project were electrical engineering and computer science PhD students Xiaochang Pei, Anita Ghandehari and Shingirirai Chakoma; Jerome Rajendran, a postdoctoral scholar in electrical engineering and computer science; and Jorge Alfonso Tavares-Negrete, a PhD student in biomedical engineering. Financial support was provided by UC Irvine’s Samueli School of Engineering.

The paper can be found at www.nature.com/articles/s41467-025-67747-9. To watch a video about the device, go to www.youtube.com/watch?v=4kAOrPkz1Sk&t=75s.

Founded in 1965, UC Irvine (www.uci.edu) has more than 36,000 students and offers 224 degree programmes. It contributes $7bn annually to the local economy and $8bin statewide.