ETH Zurich spin-out Scrona AG and Avantama, a manufacturer of specialty materials for printed electronics, have successfully processed high-performance quantum dot (QD) ink using Scrona’s electrohydrodynamic (EHD) inkjet 3D printing technology.
According to Scrona, EHD 3D printing enables fabrication at much smaller resolutions than conventional inkjet 3D printing, making it well suited to the production of semiconductors and micro-displays. Crona EHD 3D printing can achieve resolutions below 1µm.
Avantama’s perovskite QD 3D printing inks are well suited to Scrona’s micro-3D printing process, possessing the highest absorption coefficient among QDs. This allows for 3D printing of pixels with fine resolutions and good optical density, significantly reducing production time.
The companies claim that this collaboration will enable efficient and cost-effective production of 3D printed MicroLED displays with increased color purity and brightness.
“We continue to find new applications of EHD that will meet the demands of the industry by offering an additive, completely waste-free process with higher resolution capabilities than lithography patterning,” commented Dr Patrick Galliker, co-founder and CEO of Scrona.
“While conventional inkjet printheads require inks of low viscosity, Scrona has already demonstrated printing inks 1,000 times what they can process, paving the way for a much more efficient generation of MicroLED displays.”
Scrona sub-micron 3D printing with Avantama material
Scrona’s EHD electrostatic multi-nozzle 3D printing technology is said to offer significant advantages over conventional inkjet 3D printing for the production of multi-material, functional electronic products.
The company says that the nozzle-based jetting approach of current inkjet technology produces narrow droplets with high fluidic content, preventing the production of ultra-high resolution parts. Unlike conventional inkjet 3D printing which extrudes material by pushing droplets from a nozzle, Scrona’s EHD technology uses electrostatic forces to pull the material out.
These pulling forces are focused entirely on the tip of microfabricated nozzles, allowing incredibly small droplets to ejected, accelerated, and guided downwards. Droplet size can be controlled by the applied voltages, enabling the production of droplets that are one order of magnitude smaller than the nozzle.
According to Scrona, this extrusion process enables the jetting of thicker, more concentrated liquid that can form objects with much finer resolutions than conventional inkjet 3D printing.
The development of Scrona’s proprietary inkjet 3D printing technology was aided by a 2022 Series A funding round, in which the companies raised $9.6 million. The company received financial backing from AM Ventures, TRUMPF Venture, Verve Ventures and Manz Management Consulting and Investment.
This funding has enabled the company to “accelerate the industrialization” of its technology, bringing it to market through this collaboration with Avantama.
Avantama’s perovskite-based material offering possesses higher weight-based absorption than any other QDs. This translates to very high OD thickness values, ideal for Scrona’s high-resolution extrusion process. The inherent defect-tolerance of perovskite enables this notable property, meaning that a passivating shell is not required to achieve high-emission quantum yields.
This makes Avantama material, when used in conjunction with Scrona inkjet 3D printing, well suited to the production of MicroLED components.
“Conventional inkjet printing is not a viable option for emerging MicroLED displays because they use much smaller pixels than QD-OLED displays,” stated Dr Norman Lüchinger, co-founder and CTO at Avantama.
“By partnering with Scrona, we have been able to demonstrate that an OD greater than 1 can be obtained with a perovskite QD layer thickness below 2μm. This can reduce the printhead nozzle count by a factor of five and deliver a thin QD layer that improves the overall efficiency and production takt time of MicroLED display technology.”
Developments in micro-3D printing
Scrona’s EHD 3D printer is not the first designed for the fabrication of micro-scale components such as MicroLED’s. Back in 2022, Desktop 3D printer manufacturer Anycubic partnered with display panel specialist Jade Bird Display (JBD) to develop a consumer-grade MicroLED 3D printer.
Called the J1 MicroLED, this 3D printer featured a UV MicroLED display and adjustable 0.3CC light engine, enabling it to produce parts with details as small as 10µm. As such, the system was marketed as the first 3D printer of its kind to enable “low-energy consumption and a long lifespan at a competitive price.” Measuring just 175mm in height, the J1 is incredibly compact, allowing it to be easily transported and deployed for on-demand MicroLED 3D printing.
It was announced last year that Austria-based high-precision optical device developer In-Vision had collaborated with Professor Tapajyoti Das Gupta of the Indian Institute of Science-Bangalore to develop a sub-micron 3D printer.
Working with Mumbai-based 3D printer manufacturer J Group Robotics, the partners have built the 3D printer which can produce flexible, stretchable photonic devices. It is hoped that this new 3D printer will lower the cost of production for nano-scale, high-performance optical devices, disrupting the semiconductor industry in the process.
Das Gupta expects the 3D printer to be producing its first sub-micron optical components in spring 2024.
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Featured image shows a Scrona inkjet 3D printing nozzle. Image via Scrona.
