A team in Korea has developed a 3D printer that can produce ultra-high resolution quantum dot displays on flexible substrates
The team led by Dr Jaeyeon Pyo and Dr Seung Kwon Seol at Nano Hybrid Technology Research Centre of Korea Electrotechnology Research Institute (KERI),
Rather than using a thin film approach, the 3D printer produces 3D quantum dots 620nm wide and 10,000nm high on a 3 μm pitch from a nanopipette. This allows the structure of the quantum dot to be varied, producing twice the brightness across all three colours (red, green and blue) compared to thin film displays simply by varying the height of the nanopixel.
Each nanopixel was vertically printed at a constant speed of 1 µm/s. The printing process was terminated by the rapid removal of the nanopipette at a rate of 100 µm/s.
The 3D printer also produces the three colours at a resolution of 5600PPI, exceeding that of 8K QLED TV (100PPI), laptop (200PPI), and smartphone (800PPI), while surpassing the limit of commercial technology (1,000PPI). This ultra-high resolution can be used for VR and AR displays as well as beam projectors.
The display can also be printed on a flexible Polyimide (PI) or Polyethylene terephthalate (PET) substrate for wearable or rollable devices.
The 3D printing technology can also be applied to ultra-high density data storage medium anti-forgery technology using super-high-resolution encryption pattern in 3D structure camera sensor bio technology etc.
"It is not easy to find cases of using 3D printing techniques to the display industry across the world. We took a different approach from previous 3D printing research, which was mostly relying on foreign tools and equipment. It can be considered as a complete technology independence to develop an 'integrated solution' from 3D printing materials to original technology and equipment," said Dr Jaeyeon Pyo.