Page 11 - ME News Spring 2022

Research
GROUNDBREAKING 3D PRINTING
Kuhrmeyer Family Chair Professor Michael McAlpine is the lead researcher on a groundbreaking new study that could result in a new way to produce low-cost organic
light-emitting diode (OLED)
displays.
OLED display technology is used
in high quality digital displays
from television screens to
smartphones, but it’s costly and
complicated to create. The 3D
printing method developed by
McAlpine and his collaborators
makes it possible for this technology to be created by anyone, at home. “OLED displays are usually produced in big, expensive, ultra- clean fabrication facilities,” said 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 at home or on the go within just a few years, on a small portable printer.”
The group had previously tried 3D printing OLED displays, but they struggled with the uniformity of the light-emitting layers. Other groups partially printed displays but also relied on spin-coating
or thermal evaporation to deposit certain components and create functional devices.
In this new study, the University of Minnesota research team combined two different modes of printing to print the six device layers that resulted in a fully 3D-printed, flexible OLED 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. Every pixel worked and displayed light.
11