3D LED printer makes a contact lens display possible
By breaking the concept of an LED down to its most basic form, the researchers saw that they needn’t think of LEDs as little domed plastic lightbulbs, but simple stacks of interacting material. This printer can lay down an LED with a sandwich structure that’s not unlike any single pixel in an OLED display — you’ve got an emissive layer (in this case nanoparticles of cadmium selenide generally referred to as quantum dots) sandwiched between one layer that can donate electrons and one layer that can accept them. The whole thing can be fused to a surface thanks to the bottom adhesive layer, which is activated with UV light. Best of all, these printed LEDs are ultra-thin, flexible, and almost totally transparent!