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[Image above] Credit: MIT Mediated Matter

Micron3DP isn’t the only group that’s 3-D printing with glass.

A collaboration of groups at MIT has developed its own additive manufacturing process for 3-D printing optically transparent glass, called G3DP. 

The collaboration puts together heads in MIT’s Mediated Matter group, Department of Mechanical Engineering, and Glass Lab. Mediated Matter is a group within the MIT Media Lab that focuses on “nature-inspired design and design-inspired nature,” merging materials science with computation design, digital fabrication, and synthetic biology.

Although previous attempts to print glass have tried binder jetting or laser sintering approaches, those methods have limitations when it comes to glass, including producing brittle and opaque glass products.

So MIT developed G3DP, a high-heat-equipped extrusion printer that works similarly to extrusion printers that print thermoplastics. [Micron3DP was mum on details, but its process also seems likely to use extrusion.]

See the MIT magic for yourself in Mediated Matter’s video below.

Credit: Mediated Matter Group; Vimeo

According to the Mediated Matter website, G3DP has dual heated chambers. One chamber holds and extrudes molten glass into a second heated chamber, which holds the printed design above its annealing temperature until printing is complete.

As you might guess, the printer incorporates numerous ceramic components to help it hold up to the heat. Of particular importance is a ceramic print nozzle that funnels the molten glass into printed form in the annealing chamber.

The alumina-zircon-silica nozzle spews out hot molten soda-lime glass at ~1000°C, just like honey out of a squeeze tube.

The MIT innovators use computer-aided design (CAD) models to direct deposition of molten glass into the desired configuration, which rests in the printer’s annealing chamber at ~500°C, just above the glass’s annealing temperature. After printing is complete, the chamber is cooled off to anneal the masterpiece.

Check out some beautiful images of 3-D printed glass goods and the printing process itself over here at Mediated Matter’s website.

Besides printing beautiful works of art, the process is surprisingly precise. According to an open-access paper published on the technique, “The deposition of the glass layers, however, appears to be highly precise: the deviation of the filament centers from the centerline was 0.18 mm ± 0.13 mm over the analyzed section (or ca. 2.25% of the total wall thickness). The maximum deviation observed was 0.42 mm.”

The MIT also tested their creations to ensure that they were more than just for looks.

Scanning electron microscopy showed that printed objects demonstrated strong adhesion between layers, while polariscopy revealed rather homogenous stress distribution between and within layers.

Although the team continues to work on improvements to the machine and process, its work so far demonstrates clear possibilities for 3-D printing transparent and mechanically stable glass designs. 

And that’s a big deal.

The open-access paper, “Additive manufacturing of optically transparent glass,” will be published in an upcoming issue of 3D Printing and Additive Manufacturing and can be downloaded here.