face tattoo uses skin-like sensors to detect and predict mental stress

Face e-tattoo measures mental stress and brain struggles

Researchers at The University of Texas at Austin have developed an e-tattoo for the face that can detect mental stress and brain struggles. Placed mainly on the forehead, the wireless ink can decode brainwaves, which measure the strain and stress on the brain. While the traditional EEG cap is bulky and uses wires and gel before detecting and understanding the brainwaves, the e-tattoo that the researchers invented has thin, skinlike sensors designed with wavy shapes so they can stretch and stick around the face and begin detecting the user’s mental stress.

There’s a small, wireless battery attached to the thin sensors, powering up the wearable tech. Once the users ‘wear’ the face e-tattoo, it reads the brain signals as well as eye movement for mental stress. The researchers say that because the tattoo with sensors is positioned in the ‘right’ location, it receives signals accurately, which results in accurate readings. Nanshu Lu, the study’s co-senior author, adds that while the EEG caps have more sensors for different regions of the brain, ‘they never get a perfect signal because everyone’s head shape is different.’

image courtesy of The University of Texas at Austin

Wearable tech that can predict user’s fatigue

In the published study, the researchers document the trial they ran using the face e-tattoo that can detect mental stress. They asked six participants to complete a memory challenge. As the test became more difficult, their brains showed more theta and delta waves, which means the brain was working harder, while their alpha and beta waves went down, showing mental tiredness. It means that the face e-tattoo can tell when the brain is under stress or getting tired. The researchers also trained a computer program to read the brain signals from the wearable tech, which could tell the difference between low, medium, and high mental effort.

With this, the face e-tattoo can also predict when the person starts to feel mental stress and fatigue, telling them they’re about to be mentally exhausted before they even experience it. When it comes to the price, the researchers say that the chips and batteries, alongside the disposable sensors, can cost around 220 USD, which is cheaper than the traditional 15,000-USD EEG equipment. So far, the face e-tattoo that can detect mental stress only works on hairless skin, but the researchers are already working on combining it with ink-based sensors that can work on hair. With that, the wearable tech can allow for full head coverage plus more comprehensive brain monitoring.

image courtesy of Device/Huh et al.

previous study on printed e-tattoo connected to recorder | image courtesy of The University of Texas at Austin

project info:

name: E-tattoo

institution: The University of Texas at Austin | @utaustintx

researchers: Nanshu Lu, Heeyong Huh, Hyonyoung Shin, Hongbian Li, Kazuma Hirota, Carolyn Hoang, Shrikar Thangavel, Matthew D’Alessandro, Kathryn A. Feltman, Luis Sentis

study: here