A system for creating contact lenses with a built-in screen, such as the digivolution of Google Glass, is what researchers at the University of Washington are developing. In this case, The lenses are not equipped with an LED display.
As we are talking about such a tiny device, what they have done has been to print the screen with a 3D printer that produces quantum dots of LEDs, such as one of the pixels of an OLED screen. It is formed by an emitting layer (nanocrystals of certain materials, such as cadmium selenide), which is placed between two other layers, one of them provides electrons and the other accepts them.
The design is still very typical of science fiction and still has to solve some problems, such as the power supply: an external energy input is required, which involves the installation of an antenna in the lenses, in order to These can be charged wirelessly.
It’s unlikely that we will begin to see the printing of smartphone screens pixel by pixel, since bulk manufacturing processes are faster and cheaper. However, when we tackle a task as complex as putting LEDs in a circular area of the contact lens less than 2 mm in diameter, it can be useful, although expensive.