Should you go tribal? Perhaps get an Asian design? Or maybe keep things old school with a classic heart tattoo that says “Mom”? But wait, there’s another option to consider: a blood pressure tattoo. That’s exactly what a team of researchers from Texas A&M University and the University of Texas at Austin have created. Their electronic tattoo — or e-tattoo — monitors a user’s blood pressure over long periods of time, adding to the recent advances in cuffless blood pressure monitoring that include devices that are worn on the wrist, finger or in the ear.

So will this e-tattoo make you look cool? Probably not. It’s a subtle series of small marks on the underside of the user’s forearm, positioned over the radial and ulnar arteries. And no needles; the e-tattoo is applied on a person’s arm much in the way any other temporary tattoo is. But the e-tattoo is made of graphene, a highly durable and ultra-thin material that’s similar to its carbon cousin graphite.

How does it work? The user places a small sensor on their arm just above the graphene applications. Then the device introduces a weak electric current into the skin to prompt a reaction from the body (part of a process known as “bioelectric impedance analysis”) to gauge blood pressure by measuring the change in volume in the arteries. The device is hard-wired to a computer that analyzes the readings with help from machine-learning algorithms, and comes up with accurate biometric data.

One of the project’s co-leaders, Dr. Deji Akinwande, says, “All this data can help create a digital twin to model the human body, to predict and show how it might react and respond to treatments over time…. Blood pressure is the most important vital sign you can measure, but the methods to do it outside of the clinic passively, without a cuff, are very limited.”

If you’re thinking this technology would be perfect for smartwatches, you’re in good company… but ahead of your time. Smartwatches move around on the wrist and, as Dr. Akinwande’s fellow co-leader Dr. Roozbeh Jafari points out, “You need the [e-tattoo] sensor to stay in the same place because if you happen to move it around, the measurements are going to be different.” So, for now, we’ll just have to stick with the current smartwatches and their light-based blood pressure monitoring. But we’ll almost surely see a future in which medical e-tattoos are integrated with smartwatches, smartphones, and other wearables.