Gallery: How Humans and Machines Are Molting Into Modern Skins

Someday, patients with chronic diseases may not need to wear electronic monitors to keep track of glucose levels and heart rates. Their skin will do it for them — or rather, their tattoos will. Tattoos inked with conductive or fluorescent materials, perhaps nanoparticle fluids, could be a much less cumbersome medical monitoring method.

Heather Clark, a professor of pharmaceutical sciences at Northeastern University, is leading efforts to create embeddable technology that can keep people constantly connected. This summer, she debuted an invisible nanoparticle tattoo that can track glucose and sodium levels in the blood by fluorescing in certain light.

It comprises 120-nm-wide nanodroplets that contain a fluorescent dye and sensor molecules that bind to certain chemicals, as explained by Technology Review. An iPhone outfitted with a special filter is used as a light source; a greater number of molecules yields a stronger fluorescence. Currently, researchers take a photo of the fluorescence with the iPhone camera and analyze it with a computer to determine biomarker levels. Clark hopes to eventually build an iPhone app that can read the output itself.

MIT engineers have also built nanoparticle tattoos, designed to help diabetics continuously monitor glucose levels. The particles also fluoresce in the presence of glucose and infrared light, according to MIT. A user would wear some type of electronic device to provide the IR beam and interpret the fluorescence.

While a tattoo isn’t exactly painless, both systems would conceivably be less invasive than constant finger-pricking or blood draws.