Additive Manufacturing Strategies

Germanium, Silica & Titanium Lend Stability to 3D Printing Optical Glass

ST Medical Devices

Share this Article

In the recently published ‘Sol-Gel Based Nanoparticles for 3D Printing of Optical Glass,’ Peter Palencia and Koroush Sasan of Lawrence Livermore National Laboratory are innovating further in the realm of high-performance optics, using 3D printing and printable titanium-germanium-silica inks made from colloidal sol-gel feed stocks.

Although glass is such a valuable material to scientists attempting to transmit, refract, and reflect light, Palencia and Sasan point out the many challenges in using it for work like theirs. For this study, they focused on a ternary formulation of core-shell SiO2 nanoparticles coated with a TiO2 shell and GeO2 nanoparticles that could be used as a feedstock for direct ink writing (DIW) lenses.

“At the atomic level, the refractive index of glass can be adjusted to a certain value based on the composition of oxides within the glass. For example, sodium oxide and titanium oxide can be added to the glass to increase the refractive index,” explain the authors. “However, the introduction of the different dopants into the glass create potential problems as they not only drastically change the optical properties of the glass, but also its thermodynamic stability and overall viability to form a transparent glass.”

With additive manufacturing processes, a new and ‘revolutionary approach’ allows for the creation of a wide range of materials, whether researchers are using cells in tissue engineering or printing with resin.

“Although these methods have seen success in the production of other materials, a robust method to 3D print an optical lens has not been developed,” stated the authors.

Bubbles are a typical challenge—resulting in stress, which then causes cracking. Other methods have not been fully researched—such as glass created via UV curable ink. In previous research by the authors, however, using fumed silica, they had some success but still found it to be ‘an inconsistent mixture that affects all aspects of the glass.’ It tends to cluster together too, creating pieces too large for extrusion. Here, the researchers found a solution in eschewing fumed silica and replacing it with sol-gel based silica nanoparticles. It can be used for direct ink writing:

“Its transparency, refractive index, and coefficient of thermal expansion is comparable to a commercial lens,” stated the authors.

The authors found that to create functional optical glass, they had to rely on a combination of germanium, silica, and titanium. The dopants (germanium oxide and titanium oxide) caused an increase in the refractive index, while still upholding functionality and performance.

In contrast to the previous use of silica inks, the new mixture promoted stability, while great care still had to be taken during heating to avoid stress cracks.

The preparation of GeO2-SiO2-TiO2 consists of four main stages

“By varying the concentration of GeO2 and TiO2, we tested the viability of glass in terms of transparency and printability,” concluded the researchers. “The glass was transparent up to 7 mol% TiO2 and 14 mol% GeO2. Also, a higher colloidal stability of the glass could be seen through the zeta potential of the nanoparticles.

“While these glasses are not completely crack-free, a range of temperatures were identified as cause of cracking. Experiments to optimize ternary glass through the addition of surfactants and to reduce cracking during heat treatment are ongoing.”

3D printing is often used in optics, from micro-optics to 3D laser lithography, to embedded geometrics. What do you think of this news? Let us know your thoughts! Join the discussion of this and other 3D printing topics at 3DPrintBoard.com.

[Source / Images: ‘Sol-Gel Based Nanoparticles for 3D Printing of Optical Glass’]

 

Share this Article


Recent News

FDM 3D Printing Support Removal Times Cut in Half with VORSA 500

3D Printing Drone Swarms, Part 12: 3D Printing Missiles



Categories

3D Design

3D Printed Art

3D Printed Food

3D Printed Guns


You May Also Like

ICAM 2021: Keynotes on 3D Printing in Healthcare & Aerospace

At last month’s International Conference on Additive Manufacturing (ICAM) 2021 in Anaheim, California, hosted by ASTM International’s Additive Manufacturing Center of Excellence (AMCOE), a wide variety of topics were covered,...

Featured

3D Printing Unicorns: Gelato Gets $240M in Funding, Expands into 3D Printing

On-demand printing platform Gelato, based in Oslo, Norway, achieved the coveted unicorn status after a new funding round. On August 16, 2021, the company announced it had raised $240 million...

Featured

US Army and Raytheon to Use 3D Systems Metal 3D Printing to Heat-Optimize Munitions

3D Systems (NYSE: DDD) has been chosen by defense contractor Raytheon and the U.S. Army’s central laboratory to help with a design optimization project. To do that, the 3D Systems’...

Raytheon Receives Funding for Aerospace 3D Printing of Optical Components

This spring, Ohio-based America Makes, the leading collaborative partner in additive technology research, discovery, and innovation for the US, announced its latest Project Call for AXIOM, or  Additive for eXtreme Improvement...


Shop

View our broad assortment of in house and third party products.