Tattoos and body art offer intriguing possibilities for health tech wearables. We’ve written previously about tattoo stickers used to measure blood glucose and check vital signs. Rotex introduced a tattoo sensor at CES 2017 and temporary tattoos to check real-time blood alcohol content were developed at  University of California, San Diego.

MIT Media Lab‘s Dermal Abyss project applies biosensors to the skin. The biosensors change color based on factors or changes in the interstitial fluids. The MIT project detects pH levels, glucose, and sodium using four different biosensors. The sensor that reacts to pH levels switches between purple and pink. The glucose sensor changes between blue and brown. Two other sensors — one for sodium and another for pH — turn up their fluorescence intensity under ultraviolet light. Unlike temporary tattoo patches, the DermalAbyss ink is applied directly into the skin. When used by diabetics, for example, the application could replace needle sticks multiple times a day with a tattoo applied once that would monitor blood glucose continuously.

Testing and evaluations to date have been with pig skin ex vivo (removed from a pig). Applications for the DermalAbyss tattoo ink could include continuous monitoring for medical diagnosis, self-monitoring, and data encoding. At present, however, there are no plans to pursue clinical applications of the technology.