Researchers Take Advantage of 3D Printing To Create Flexible OLED Display

For decades researchers have looked to additive manufacturing, or 3D printing, as an alternative method for manufacturing electronics. This interest has only continued to increase in today's world as supply chain issues related to traditional manufacturing have severely impacted the industry.

 

A 3D printed OLED display. Image used courtesy of the University of Minnesota Twin Cities

 

This week, researchers from the University of Minnesota Twin Cities have announced that they were able to successfully 3D-print a working OLED display.

In this article, we'll talk more about why 3D printing might be a good fit for electronics and how the researchers could use the technology to print a display.

 

Why 3D Print Electronics?

In many ways, 3D printing could revolutionize the way engineers create and manufacture electronics. 

For starters, 3D printing can be beneficial for electronics because it enables an unprecedented amount of space savings and customizability. 

Traditional PCBs and components are typically confined by traditional manufacturing processes, only possible in certain geometries and only exhibiting specific material properties (i.e., flexibility, density, etc.). 

Instead, additively manufactured components and PCBs allow for high levels of customizability and control. This customizability and added control can help enable design engineers more flexibility to customize smaller form factors and enclosures for applications like wearables. 

 

3D printed flexible PCB. Image used courtesy of Technic

 

On top of this, the value of 3D printing electronics has become increasingly apparent amongst the severe supply chain crises affecting the industry today. 

Should 3D printing electronics become a reality, an individual engineering firm would have the ability to print PCBs and components directly in-house without the need to keep a supply of components. Instead, they might be 3D printed as needed, reducing dependence on the supply chain and making the process cheaper and more streamlined overall.

 

New 3D-Printed OLED Display

This week, researchers from the University of Minnesota Twin Cities made headlines when they successfully 3D printed a working OLED display.

In their paper in Science, the researchers explain that, though researchers had attempted this feat before, it was never successful due to various challenges. Some of these previously unsolved challenges include the inability to create uniformity in the extrusion-printed active layers and the need for repeatable and stable polymer-metal junctions between the active layer and the cathode. 

The research group overcame these challenges by combining two forms of printing. 

 

The process used to successfully 3D print an OLED display. Image used courtesy of Su et al

 

First, the team shaped the display's bottom interconnects and defined pixel location and size by using extrusion-based printing of metal nanoparticle conductive inks. 

Next, the researchers coated the active areas with a conductive polymer to form a composite anode structure. 

For the active layers, a spray nozzle was integrated on the 3D printer to atomize the inks into droplets to tens of micrometers, allowing a finer resolution printing and more control over uniformity. 

Finally, insulation and encapsulation were created again using extrusion-based printing methods.

The resulting prototype worked better than expected, with the display coming in at 1.5 inches x 1.5 inches and containing a total of 64 pixels, all of which worked and displayed light. 

Compared to traditional OLED manufacturing methods, which require expensive, ultra-clean facilities, the researchers' method was significantly less expensive and more accessible.

As the world moves towards adopting more efficient technology and trying to reap the benefits that 3D printing can offer, there will be more devices and research aiming to push it to the next level.