Researchers have developed a new colour-changing tattoo ink that responds to changes in the body, such as blood sugar and sodium levels.

Using a liquid with biosensors instead of traditional ink, scientists want to turn the surface of the human skin into an "interactive display" - an idea that makes this proof-of-concept an exciting one to watch. Technology like this could become a revolutionary new way to monitor health.

The project, called DermalAbyss, is a collaboration between researchers from MIT and Harvard Medical School, combining efforts from Fluid Interfaces and biotechnology.

So far, the team has developed three different inks that shift colour in response to changes in interstitial fluid - the stuff that sloshes around between our cells, comprising some 16 percent of the human body weight.