In a groundbreaking development, researchers in the United States have introduced a potentially game-changing method for measuring brain activity: printable, temporary “e-tattoos.” These advanced, easy-to-use alternatives to traditional EEG caps could make brain monitoring more convenient and comfortable, while maintaining the same reliability as current methods.
Electroencephalograms (EEGs) are widely used to diagnose conditions such as epilepsy, sleep disorders, and brain injuries by recording electrical activity in the brain. Despite being noninvasive, EEG tests can be cumbersome. The process of setting up the EEG cap is time-consuming, and the sensors require reapplication of conductive gel every couple of hours, which can be uncomfortable for patients.
Now, a team of scientists from the University of Texas at Austin and the University of California, Los Angeles, believe they’ve solved many of these issues with their new printed EEG technique. Published this week, their research introduces a temporary tattoo-like system that is easier to use, quicker to apply, and just as effective as conventional EEGs.
“The holy grail for EEG is a sensor that patients can wear for long periods of time, outside the clinical setting, and without the need for constant maintenance,” said Nanshu Lu, a professor at UT Austin and one of the lead researchers. “What we’ve developed opens the door for more mobile EEG sensing.”
The e-tattoo system involves the use of biocompatible ink to print electrodes and interconnects directly onto the skin. A five-axis robot prints the ink mesh, based on a 3D scan of a patient’s head, using a custom-developed algorithm. The entire process takes around 15 minutes to complete, and it only requires patients to remain still during application.
However, the researchers noted that head movements during the process could lead to slight delays, as additional calibration is needed to update the coordinates. To address this, they plan to incorporate visual tracking systems into the printing process for better accuracy.
Once applied, the conductive ink, which is just half the thickness of a human hair, records brain activity with “sufficient and stable conductivity” for more than 24 hours. The e-tattoos are also stretchable and can be printed even over short haircuts, offering an improved experience compared to traditional EEG caps.
After the scan, the tattoos can be easily removed using soap and water or an alcohol wipe, offering a significant advantage in terms of convenience and comfort. Not only do these e-tattoos deliver the same high-quality signals as gel-based electrodes – the current gold standard in EEG technology – they also offer longer continuous usability.
While the technology presents numerous benefits, there are still a few limitations. For instance, it may not work as effectively on individuals with longer hair, as hair interference could disrupt the sensor’s contact with the scalp. The team is exploring the use of robotic combs or fingers to separate hair in target areas to overcome this issue.
Another challenge is that the tattoos tend to rub off during sleep, making them unsuitable for sleep monitoring at this stage. The researchers are aware of this limitation and plan to refine the design to address it.
Despite these challenges, the e-tattoo system represents a promising leap forward in EEG technology, offering greater comfort, mobility, and usability, all while maintaining reliable performance. As research progresses, this innovation could play a key role in the future of brain activity monitoring, with the potential to revolutionize how conditions like epilepsy and sleep disorders are diagnosed and managed.
And, as a bonus, the tattoos even look cool – providing a futuristic, tech-savvy alternative to the bulky, wire-laden EEG caps of today.
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