University of Minnesota Twin Cities scientists have successfully 3D printed a fully flexible organic light-emitting diode (OLED) display using a customized printer.
The research which has been published in the American Association for the Advancement of Science (AAAS) jounral ‘Science Advances’, could pave way for low-cost OLED displays that can be widely produced by anyone at home using 3D printers, instead of by technicians in expensive microfabrication facilities.
“OLED displays are usually produced in big, expensive, ultra-clean fabrication facilities,” says Minnesota professor and senior author of the study Michael McAlpine.
“We wanted to see if we could basically condense all of that down and print an OLED display on our table-top 3D printer, which was custom built and costs about the same as a Tesla Model S.”
This isn’t the group’s first attempt at 3D printing OLED displays; prior to the current breakthrough, they had struggled with the uniformity of the light-emitting layers.
Other groups too have partially printed displays but have also relied on spin-coating or thermal evaporation to deposit certain components and create functional devices.
In this new study, McAlpine’s team combined two different modes of printing to print the six device layers that resulted in a fully 3D printed, flexible organic light-emitting diode display.
The electrodes, interconnects, insulation, and encapsulation were all extrusion printed, while the active layers were spray printed using the same 3D printer at room temperature.
The display prototype was about 1.5 inches on each side and had 64 pixels. Notably, every pixel worked and displayed light, says Ruitao Su, first author of the study and now a postdoctoral researcher at MIT.
Su says that the 3D printed display is also flexible and can be packaged in an encapsulating material, which could make it useful for a wide variety of applications.
“The device exhibited a relatively stable emission over the 2,000 bending cycles, suggesting that fully 3D printed OLEDs can potentially be used for important applications in soft electronics and wearable devices,” says Su.
The next goal for McAlpine and his team will be to 3D print OLED displays that are higher resolution and come with improved brightness.
Image and content: McAlpine Group/University of Minnesota