Check out this fun article from discovery about a Nano Ink 'Tattoo' that could monitor glucose levels. Here is the link and a quick excerpt as to what it would look like.
"If the molecules mostly latch onto glucose, the ink appears yellow. If glucose levels are low, the molecule latches onto the glucose mimic, turning the ink purple. A healthy level of glucose has a "funny orangey," color, according to Clark. The sampling process repeats itself every few milliseconds.
Time measured in milliseconds is much faster than then most current blood testing systems, and certainly less painful. But is it as accurate?
Glucose levels in the skin, where the ink would be injected subcutaneously, might not necessarily reflect the more critical measurement of glucose levels in the blood. Some studies show that skin glucose levels can lag up to 20 minutes behind blood glucose levels, while other show a much faster change.
"It's an interesting question," said Clark. "It's one that we might even be able to help answer."
Even if there is a significant lag time between blood and skin glucose levels, a small tattoo, in the several square millimeter range, according to Clark, would let diabetics know if an abnormally high or low reading was either returning to a normal level or getting worse."
I've always thought it would be cool to have a diabetes alert tattoo- but if I could get a two for one deal like this, I'd do it! It wouldn't replace a meter (or a CGM) but it would help me out- say if you insulin goes bad or if it went high and I started getting emotional I could look down at my tattoo and be like "wups I better go check!" Also I'd have a better idea of how long it takes for insulin to act in my body.