In 2015, an interdisciplinary research team led by MIT Media Lab’s Mediated Matter Group introduced a technology to 3D print molten glass, accompanied by a display of its stunning results: glass objects with gradated profiles, colors, and opacities that, when internally illuminated, scattered light in complex caustic patterns. But the team considered its foray only an initial step, and almost immediately began exploring ideas to refine and scale its additive manufacturing method.
Nearly two years later, at the Lexus Yet exhibition at Salone del Mobile, in Milan, Italy, this April, the Mediated Matter Group, directed by MIT associate professor Neri Oxman, debuted the capabilities of Glass 3D Printing II (G3DP2) in an installation that demonstrated the technology’s progression from producing objects at a tabletop scale to an architectural scale, plausible for use in building applications.
The “Glass II” installation comprised three 3-meter-tall (10-foot-tall) columns, or “light totems,” of stacked glass module, each approximately 8 inches tall and printed using the G3DP2 platform. Each column had a unique and constantly changing profile that, when viewed in plan from top to bottom, originates as a three-, four-, or five-petal shape and gradually branches out into multiple lobes, bifurcated from each original petal with a constant turning radius. Hence, the three-petal column ultimately has six lobes at its base, the four-petal column has eight, and such.
Similar to a multifloor-spanning building column, the glass columns increased in area of printed material from top to bottom via the growing number of radial arrays to correspond with the increase in required structural capacity since the glass component at the base must support the dead load of the glass components stacked atop it. In a compression test shown in a video by the group, one eight-lobe glass module begins to exhibit audible cracking when loaded upward of 250,000 pounds.
Visually, the unique profiles of each printed layer lend to the creation of stunning kaleidoscope-like patterns of caustics, which the group put on full display using an LED luminaire programmed to travel up and down the inside of each column. Two dark-mirrored surfaces mounted on the end walls of the installation space created the illusion of an infinite, luminous colonnade.
To manufacture the glass modules, the Mediated Matter Group reworked the machine architecture and process-control operations of its first-generation 2015 glass printer using knowledge about the material properties and behaviors of silicate glass, the print medium.
G3DP2 is four times bigger in footprint than its predecessor, weighing in at more than one ton and capable of processing up to 30 kilograms (66 pounds) of molten glass in one print run. Oxman says the current limiting factor to the build size is the printer gantry.
The group also outfitted G3DP2 with a digitally integrated thermal control system that accommodates the different stages of glass forming—useful as the extruded molten glass takes form inside the annealing kin cum print-build volume. The printer also features a four-axis motion control system to improve flow control and spatial accuracy and precision, allowing the team to vary the extrusion thickness and to achieve the tight turning radii required to print the successively smaller glass lobes from the top to bottom components of the columns.
Following the group’s success with 3D printing glass at small and large scales, Oxman sees a number of potential directions and investigations for the research. They include “hardcoding structural instabilities to generate internal spaces” between successive layers of printed glass to create predetermined orifices or porosity; leveraging “auto coiling,” or the deposition of molten glass in the interim between the print nozzle tip and the print bed, to create patterns in detail finer than the movement allowed by the gantry (akin, perhaps, to Jackson Pollock’s ability to paint with strokes finer than his brush size and also beyond an arm’s reach); and exploring the use of color to effect the material’s ability to absorb light and heat.
As for the fate of the iridescent columns, Oxman is anticipating that they “will likely reappear at a few major cultural institutions in the near future.”
The G3DP2 team includes Chikara Inamura (project lead), Michael Stern, Daniel Lizardo, Tal Achituv, Tomer Weller, Owen Trueblood, Nassia Inglessis, Giorgia Franchin, Kelly Donovan, Peter Houk (project adviser), and Neri Oxman (project and group director). Project associates include Andrea Magdanz, Susan Shapiro, David Benyosef, Mary Ann Babula, Forrest Whitcher, Robert Philips, Neils La White, Paula Aguilera, Jonathan Williams, Andy Ryan, and Jeremy Flower. And, finally, the project’s collaborators include Lexus, Pentagram, Simpson Gumpertz & Heger, Front, MIT Central Machine Shop, and Almost Perfect Glass (AKA APG).