New Electronic Ink Tattoo Measures Stress Without Interfering With Your Day

What does this palm reader say about your mental outlook?

Where the pandemic has held us back, it has also fueled positive conversations on mental health. As open as people have become about talking about stress, though, they may still have their reservations about wearing visible sensors to assess the less tangible aspects of health. Not everyone is ready to wear their hearts on their sleeves, as the saying goes.

Researchers at the University of Texas at Austin and Texas A&M University have, therefore, created an electronic tattoo (e-tattoo) that rests seamlessly on your palm and measures your stress level while you go about your day. It negates the need for the more bulky gear that’s currently in use, which the creators note isn’t just tied with social stigma but can also be less accurate, since the equipment tends to shift around or even fall off with movement.

A wearer’s emotional state is measured by how wet their palm gets when they’re excited or anxious, a biological marker of stress. The e-tattoo connects to a smart watch, which it transmits data to via electrodermal (EDA) activity, and is nearly invisible.

Not only is it weightless, but it can also assess a person’s mental health every day without them having to visit the doctor.

“It’s so unobstructive that people sometimes forget they had them on, and it also reduces the social stigma of wearing these devices in such prominent places on the body,” explains Nanshu Lu, professor in the Department of Aerospace Engineering and Engineering Mechanics and the project’s leader, in a news release. The team has published its findings in a paper in the Nature Communications scientific journal.

The tattoo’s ink is made from graphene—an increasingly prevalent choice for e-tattoos that is highly conductive and similar to the graphite found in pencils, but is atomically compact and, therefore, one of the thinnest yet most durable materials in the world. In the same vein, scientists from the aforementioned universities have previously developed a graphene e-tattoo that can track blood pressure outside of the clinic.

The drawback of graphene is that it’s so thin that any movement in the palm can interfere with a reading. To continue using the material while retaining consistent results, the researchers wove a ribbon—made up of two overlapping layers of graphene and gold—back and forth like a snake for greater structural integrity.

The serpentine tattoo can withstand the strain of hand movements from daily activities like opening doors, running, and driving. The ink’s close proximity to a smart watch helps with the reader’s precision too.

The team was inspired by the increasing use of virtual reality and gaming in treating mental illness. Unlike some of those solutions, however, the e-tattoo can deliver objective results of a person’s emotional progress. As such, it could even be used to work hand in hand—pardon the pun—with other forms of therapy to accelerate recovery.

[via ScienceDaily, Graphene-Info, University of Texas at Austin, images via various sources]