Tattoo ink that changes color could be used to monitor health

By Sally Robertson, B.Sc.Oct 2 2017

Scientists from Harvard Medical School and MIT have designed a tattoo ink that can monitor a person’s health by changing color to indicate dehydration or an increased blood sugar level, for example.

Credit: Halyna Parinova/Shutterstock.com

The technology, which combines biosensitive inks with conventional tattoo artistry, addresses the limitations of the wearable devices that are currently used to monitor health.

Postdoctoral fellow at Harvard, Ali Yetisen, says: “We were thinking: New technologies, what is the next generation after wearables? And so we came up with the idea that we could incorporate biosensors in the skin.”

Yetisen says the idea was to go beyond what is available through wearables today, which are limited in that they do not seamlessly integrate with the body, battery life is short and wireless connectivity is required - factors that can all be overcome when the biosensitive tattoo ink is used.

The “Dermal Abyss” inks change color in accordance with the chemical make-up of the body’s interstitial fluid. Inks include ones that change from green to brown in response to an increasing blood sugar level and a green ink that becomes more intense as sodium levels increase, which is an indicator of dehydration. The team tested the inks by tattooing them onto the skin of pigs and then noting any change in color or intensity that occurred in response to different biomarkers.

The research was a proof-of-concept study and therefore requires refinement. For example, if the technology is going to be used as a medical product, stabilizing inks that do not fade or diffuse into nearby tissue will need to be developed. However, Yetisen says, once the problems are ironed out, the technology’s applications could be quite broad. People with chronic conditions could have the inks incorporated into long-lasting tattoos and shorter-term monitoring could be achievable with temporary designs.

Jiang says the hope is that the study will inspire scientists and artists alike to think about the technology’s potential and start asking questions about any ethical issues that might arise such as people’s reluctance over having their health information available for all to see.

“The purpose of the work is to light the imagination of biotechnologists and stimulate public support for such efforts,” says Jiang. “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.”