In response to overly worrisome parents' pleas that tattoos must have some sort of health detriment (and thus their kids should certainly rethink that massive sleeve they're saving for), Harvard researchers have come out with a new project called 'Dermal Abyss'. Beyond making tattoos healthy, the project has come out with a biosensitive ink that reacts to skin to relay health data through the tattoo itself.
The ink in the Dermal Abyss project is capable of changing colors based on chemical changes in the body. The ink measures the concentrations of glucose, sodium, and pH in skin cells, and it shifts hues based on the levels of those compounds. At the current stages of the project, the researchers have developed a green ink that changes intensity to detect dehydration and a pink ink that turns blue when pH levels rise.