Smart tattoos use biosensitive ink to monitor medical conditions

Technology News | October 2, 2017

By Rich Pell

Developed at Harvard, the biosensitive inks, when used as traditional tattoo artistry, are seen as a way to address limitations of current wearable biomedical monitoring devices. The latter don’t seamlessly integrate with the body, and typically require battery power – and associated frequent recharging – as well as some form of wireless connectivity.

“We were thinking: New technologies, what is the next generation after wearables?” says Ali Yetisen, a Tosteson postdoctoral fellow at HMS and Massachusetts General Hospital. “And so we came up with the idea that we could incorporate biosensors in the skin.”

Conducted as a proof of concept, the researchers’ project – called “Dermal Abyss” – uses tattoo inks that change color according to the chemistry of the body’s interstitial fluid. So far, the researchers have developed two biosensitive inks: one that changes from green to brown as glucose concentration increases, and a fluorescent ink that grows more intense (when viewed under special light) as sodium concentration rises, a sign of possible dehydration.

The inks, say the researchers, could be used in long-lasting tattoos to help monitor chronic conditions or in temporary designs for shorter-duration needs. The ink can even be invisible in natural light and readable only under particular kinds of light, perhaps even from that of a smartphone.

The researchers have developed an app that can analyze a picture of a sensor and provide quantitative diagnostic results. However, further work — such as stabilizing the inks so designs don’t fade or diffuse into surrounding tissue — is still needed before they can become a medical product.

“The purpose of the work is to light the imagination of biotechnologists and stimulate public support for such efforts,” says Nan Jiang, a postdoctoral fellow at Harvard Medical School and Brigham and Women’s Hospital. “These questions of how technology impacts our lives must be considered as carefully as the design of the molecular sensors patients may someday carry embedded in their skin.”

For more, see “The dermal abyss: interfacing with the skin by tattooing biosensors.”