During surgery, doctors and pilots in the sky face situations where lives are at stake, based on their judgment. The same is true for those operating heavy equipment like high-altitude cranes or working at disaster sites. If their mental stress surpasses certain limits, it can lead to severe accidents. They can step out of the operating room or cockpit for exams and prescriptions, but no one understands the crisis situations they face while on duty.
Scientists have developed a device that allows them to understand individuals experiencing stress in their daily lives anytime and anywhere. It's an electronic tattoo (e-tattoo) the size of a stamp that adheres to the face. When stress reaches a dangerous level, it can send out a warning and transfer tasks to artificial intelligence (AI) or colleagues. Once commercialized, it is expected to help prevent mistakes by mental laborers who are constantly in a state of tension and protect their health.
◇Measures brain waves and eye movements when adhered to the forehead
Nanshu Lu, a professor in the aerospace engineering department at the University of Texas, and his research team announced on the 30th in 'Device,' a sister journal of the international scientific journal Cell, that they have developed an electronic tattoo (e-tattoo) that automatically measures the mental workload of people under stress, such as pilots and surgeons.
Professionals with high levels of stress regularly assess their mental workload. However, surveys make it difficult to achieve objective evaluations. There are brain wave (EEG) audits that measure brain signals and eye movement detection tests like electrooculography (EOG), but the equipment is large, requiring visits to examination rooms, and movement during tests can lead to errors. Therefore, there are no means to measure stress levels during work.
The University of Texas research team solved the problem with electronic skin known as an electronic tattoo. The electronic skin adheres to the body, collecting health information and providing treatment through electronic devices. The disposable electronic tattoo consists of electrodes made of graphite and a battery embedded in clear film. Four electrodes on the forehead detect brain waves, and eye movement sensors near the eyes capture eye movements.
The research team tested the electronic tattoo on six participants. They conducted an experiment showing 20 characters on a computer screen and asked participants to identify the differences from the previous screen. As difficulty increased, brain wave activity detected by the sensors rose, indicating mental stress. The research team trained the results into artificial intelligence (AI).
The test results showed that the electronic tattoo accurately distinguished participants' mental stability or stress levels. Particularly, it maintained accuracy even when participants moved their heads or blinked. Existing testing equipment can produce errors if the body shakes. The researchers noted, 'This means it can be utilized in dynamic environments like operating rooms or cockpits.'
◇Automatically transfers tasks to AI when stress levels are high
Professor Lu stated that the electronic tattoo can be produced for less than $200. The research team is currently developing a system to decode signals from the electronic tattoo on a computer and send them to an app, which will warn when the workload becomes excessive. If a situation arises where tasks cannot be performed at all, it may also be developed to automatically transfer tasks to AI or colleagues. This would help prevent workers from missing important signals or making mistakes due to mental stress, which could lead to major accidents.
Of course, it is not necessarily the answer to simply reduce or simplify work when mental stress is high. If the mental workload is too low, individuals may become bored and lose focus. Professor Lu noted, 'Previous studies have shown that mental functioning is optimal when the workload is neither too low nor too high,' adding that 'the electronic tattoo can also detect situations where workers are becoming bored.'
Of course, there are still questions to resolve before commercialization. Yael Hanein, a professor in the electrical engineering department at Tel Aviv University in Israel, pointed out in an article published in IEEE Spectrum, 'Additional validation may be necessary for unpredictable activities where the entire body is moving for field application.'
References
Device (2025), DOI: https://doi.org/10.1016/j.device.2025.100781