What if we could programme the colourful cells thant can be found in cephalopods and chameleons to change and behave as we require. And then transplant them to our skin, e. G. on our forearm, to have a biological screen that can display time, reminders or text messages.
Iridiphore cells work by having guanin nanocrystals on their surface. The cells can expand and therefore change the structure of these crystals. This affects which spectrum of light is reflected and creates the optical illusion of colourchanging.
When they are very excited they only reflect light with a wavelength longer than 380 nm which would be yellow to red. When very relaxed they reflect wavelenghts over 240 nm which would appear blue.
To make the cells behave due to a digital programme we would have to translate it into cell signals, which could happen in something as a signal transformer.
Here I built a model, trying to show the process of structure change of the nanocrystals by cell expansion. Just imagine the colour would change from yellow, when inflated, to blue when empty.