MIT Researchers Discuss the Evolution of Their Glass 3D Printer

Researchers at MIT were among the first to 3D print glass, creating the G3DP machine a few years ago to create intricate glass structures. Last year, they scaled up the project with G3DP2, a platform that enabled them to 3D print glass on an architectural scale. Now these researchers have documented their work on G3DP2 in a paper entitled “Additive Manufacturing of Transparent Glass Structures.”

The researchers had two main goals in the development of G3DP2:

• Develop an industrial-scale molten glass feedstock 3D printer by extending the research previously conducted at MIT, enhancing the material properties and range of products that could be produced.
• Develop an architectural-scale 3D-printed glass structure to evaluate the practical capabilities of the new system in an industrial production.

The new platform, they explain, was designed as a two-part vertical assembly: an upper, stationary thermal module with a digitally integrated three-zone heating control system regulating glass flow and a lower, motion module with a four-axis CNC system that moves the print bed.

“In this architecture, the thermal energy applied to the heating system was decoupled from the mechanical load of the motion system,” the researchers state. “This allowed for improved durability of both systems through careful consideration of material properties and detailed analysis of constituent parts supporting each separate module. Still, critical focus was given to the print head itself, situated at the interface between the modules and requiring the highest thermal and mechanical performance from its material choice.”

The researchers describe the upgrades they made that turned G3DP into G3DP2, one of the fastest 3D printers in the world, independent of material. Their objectives were increased speed and scale as well as improved reliability and repeatability, and they achieved all four. Several tests were conducted, beginning with using pens to evaluate motion, then moving on to actual 3D printing. The researchers discuss how to understand and control the behavior of the 3D printed glass, as well as the specifications, engineering and control of the platform.

Once G3DP2 was completed, the researchers used it to 3D print three-meter-tall glass columns for the Lexus “Yet” exhibition at Milan Design Week 2017. The columns consisted of 15 unique 3D printed glass components that were assembled vertically with “thin silicone film joinery and steel post-tensioning systems to ensure vertical stability.” Each column contained a mobile LED light module set on a linear motion system, with the intersection of the moving light rays and the morphology of the glass structures creating a beautiful light show as well as a demonstration of the capabilities of MIT’s 3D glass printer.

“In the future, combining the advantages of this AM technology with the multitude of unique material properties of glass such as transparency, strength, and chemical stability, we may start to see new archetypes of multifunctional building blocks,” the researchers conclude. “Transparent and hollow-section glass tubes simultaneously act as an heating, ventilation, and air conditioning (HVAC) system, performing as structure and vasculatures at the same time at building scale, through which synthetic and biological mediums circulate and react to incoming sunlight and surrounding temperature, passively regulating the building while illuminating the interior space as if they were a dynamic stained glass—embodying the fundamental shift in the notion of glass in architecture from human centric toward a symbiosis between human, inhuman, and the built environment.”

Authors of the paper include Chikara Inamura, Michael Stern, Daniel Lizardo, Peter Houk and Neri Oxman.

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