The project is called Dermal Abyss and was conducted as a proof of concept to replace current wearable monitoring devices for medical uses which have a short battery life and need wireless connectivity. The ink changes color based on the chemistry of the interstitial fluid in the body. In the experiment, it is able to change from green to brown as glucose levels increase. The green ink grows more intense as sodium concentration increases, which is an indication dehydration.
Medical tattoo – image from Harward
Another variant of the medical tattoo could use invisible inks which can only be seen under certain colors of light that could be produced by a smartphone.. An app is able to analyze an image of a sensor and provide diagnostic results. The most unexpected part of this project: it is only developed for scientific purposes, there are currently no plans to develop the biosensor ink into a medical product, or progress with clinical trials, at least not now.. It helped researchers to better understand how the ink could potentially be useful in a wide variety of applications even for astronauts in the space missions.