How Electronic Tattoos Work

I Sing the Tattoo Electric

In the future, epidermal electronics like this may beam infant vital signs right to mom's smartphone.
In the future, epidermal electronics like this may beam infant vital signs right to mom's smartphone.
Todd Coleman/UC San Diego Jacobs School of Engineering

Say what you will about modern medicine, but there's no corner of the human body that we can't prod and probe with technological precision. From brain scans to blood tests, you're just a needle prick, a skull cap and a half a dozen electrodes away from a barrage of test results. But that's exactly what hampers extended monitoring outside the hospital.

After all, a police informant wouldn't carry a bulky audio recorder into a meeting with a deadly mob boss, would he? No, he'd wear as minimally invasive a wire as possible -- something that wouldn't hamper his style or draw unwanted attention. Likewise, no one wants to lug a battery pack and wear clusters of skin-irritating suction cups for daily health monitoring.

That's where the notion of epidermal electronics promises to change the game, allowing continued health monitoring in the real world without unnecessary hindrance.

The University of Illinois at Urbana-Champaign's Dr. John A. Rogers set his sights on the possibilities of electronic tattoos back in 2008, founding his "electronics everywhere" (and he means everywhere) company MC10. With a background in both applied physics and chemical engineering, Rogers aimed to bridge the man/machine gap in health care by making electronics more organic. In other words, he set out to create technology that bends and conforms to the squishy, sticky, leaky, itchy, hairy world of our bodies in motion.

Silicon provided the first major hurdle to this world of skin-soft cybernetics. Believe it or not, this substance originates not in Hollywood breast implants but in a crude, gray crystal mined from the Earth. From this, we create the brittle computer chips that power our high-tech lives.

How do you make this rigid technology bendable and stretchable? Rogers and his team arranged tiny silicon wires into coiling patterns and wove them through slender rubber patches. These coils expand, they contract and link all the functional parts of the device from the sensors and antennae to LED lights.

Need to have an EEG to measure your brain waves? Just slap a patch on your forehead, apply some over-the-counter liquid bandage spray and continue your afternoon on the beach as planned. The patch collects energy from the sun, reads your vitals and then transfers the data out to an external device. Earlier models still depended on a wired connection between patch and computer, but Rogers' team continues to work on improved wireless transmission systems -- including WiFi and network compatibility.

Early electronic tattoos monitored muscle, heart and brain activity. From there, the developers expanded into pregnancy monitoring in humans and actual muscle stimulation in rats. Rogers has also introduced the technology beneath the skin, using stretchable electronics on a balloon catheter inserted inside the human heart.

And if you think all of that sounds high-tech, just wait until you read what Rogers envisions for the future.