Presently, OLED screens are manufactured by specially trained technicians in large high-tech factories. Now, however, scientists have managed to 3D print a flexible OLED display, paving the way for small businesses and even individuals to one day be able to do the same thing themselves.
The device was created by a team at the University of Minnesota Twin Cities, led by Prof. Michael McAlpine and PhD graduate Ruitao Su.
Although other groups have previously constructed partially 3D-printed OLED (organic light-emitting diode) displays, those teams also relied on more complex techniques such as thermal evaporation and spin-coating. By contrast, the U Minnesota display was entirely 3D printed, utilizing a custom-built tabletop 3D printer that cost "about the same as a Tesla Model S."
The display is made up of six layers, which were printed in two different fashions – both by the same printer. Extrusion printing was utilized to deposit the interconnects, insulation, and encapsulation material, while spray printing (at room temperature) was used for the active layers.
The proof-of-concept finished product takes the form of a square display measuring about 1.5 inches (38 mm) per side and incorporating a grid of 64 pixels, each one of which emits light. It continued to work over the course of 2,000 bending cycles, suggesting that it may be well-suited to use in wearables or other soft electronics.
McAlpine, Su and colleagues now plan on increasing both the resolution and the brightness of the display. They believe that the technology could make its way into real-world use relatively soon.
"The nice part about our research is that the manufacturing is all built in, so we're not talking 20 years out with some 'pie in the sky' vision," says McAlpine. "This is something that we actually manufactured in the lab, and it is not hard to imagine that you could translate this to printing all kinds of displays ourselves at home or on the go within just a few years, on a small portable printer."
A paper on the research was recently published in the journal Science Advances. The printing process is demonstrated in the video below.
