Swiss scientists at ETH Zurich announced they have developed a 3D printing process that will produce geometrically complex objects from glass.
Today, glass is a commonplace item.
Glass covers buildings across the world, contains the liquids that we use, warps itself into artistic shapes, and might even be the conduit through which you’re reading this article. However, the mastery of the manufacturing and distribution of glass has historically been a complicated tale that’s riddled with monopolistic secrecy, international intrigue and the wild accumulation of wealth.
While today’s glass manufacturing environment deals less with statecraft and more with mundane proprietary law, transmuting the base materials of glass into a complex and transparent solid has proven difficult for additive manufacturing pioneers.
In recent years, various attempts to 3D print glass have been somewhat successful, but for each successful method there have been critical drawbacks—fused deposition modeling (FDM)-like glass printing methods require immense energy inputs and specialized heat resistant equipment, while powdered-sintering solutions can produce quality products, provided they are geometrically simple.
Enter the Swiss team.
According to ETH, the researchers have developed a special resin that combines plastic, organic molecules and glass precursors that react to a standard photolithographic additive manufacturing technique, Digital Light Processing, to build complex structures.
During the printing process the plastic element of the resin is bathed in UV light to cure a layer of geometry, building up the object layer by layer. That plastic forms the scaffolding upon which the resin’s organic molecules and glass precursor elements can be hung in a complex arrangement.
Various parameters in each layer can be changed by adjusting the UV light intensity, including pore size: weak light intensity results in large pores; intense illumination produces small pores. “We discovered that by accident, but we can use this to directly influence the pore size of the printed object,” says Kunal Masania, one of the researchers at ETH Zurich.
Once the geometry of an object has been printed, the result is introduced to a kiln, where it is fired twice—once at 600˚C to burn off its plastic framework and then again at about 1,000˚C to transform the ceramic precursor and organic molecules into solid glass.
So, where’s the rub?
The ETH team explains that during the firing process, the object built using its resin and technique shrinks, which might be a concern for some manufacturers. Furthermore, the researchers say that their method of additive glass manufacturing is limited to building small objects.
However, despite the size limitation of the new glass printing technique, at least one Swiss glassware company is interested in licensing the technology.
The manufacturer is unnamed, but a quality lens making firm might be interested in exploring this technology to create complex, miniaturized glass articles for phones or other technologies.