While tattoos have exploded in popularity over the last 10 years, they're not much more than a way to express yourself -- and, hopefully, the skill of the person inking that permanent decoration under your skin.
However, Researchers at MIT Media Lab and Harvard Medical School have taken things a step further: by turning tattoos into wearable health monitors that you won't ever be able to forget at home or at the gym like a FitBit or glucose meter.
The research project called Dermal Abyss experimented with swapping traditional tattoo ink with different material that could react, via a change in color, to say, dropping blood sugar or if a person was getting dehydrated.
The project from MIT Media Lab researcher Katia Vega and scientists from Harvard Medical School used pig skin to simulate how these high-tech materials would react to changes in the fluid under a person's -- or in this case, a pig's -- skin. The porkers' covering makes a suitable analogue to human tissue.