For some time now, MIT’s Mediated Matter Lab has been working on developing an additive manufacturing platform capable of printing 3D structures made from glass. Despite having become something of a ubiquitous material in the 19th century thanks to new manufacturing innovations in the Industrial Revolution, glass has remained a tricky material in terms of fabricating complex geometries or custom shapes. In its research, the Mediated Matter Lab has set out to find a solution to these challenges.
Though the project has been in the works for some time—readers might remember that the lab showcased a 3D printed glass installation in Milan in 2017—the Mediated Matter Lab recently published an in depth study about its glass AM platform, and specifically the G3DP2 3D printer which was utilized to produce the three-meter-tall glass columns unveiled at Milan Design Week 2017.
The recently published study has shed more light onto the innovative glass 3D printing technology being developed at MIT and the potential applications that printed glass could be used for.
“One of the oldest production materials, glass involves complex material chemistry and requires extreme working temperatures underlying the persistent challenges associated with its design and production,” the study reads. “AM with molten glass presents a potential path toward production of highly complex geometry and custom-designed objects while retaining the optical transparency and chemical stability available through traditional manufacturing processes.”
The G3DP2 platform developed by MIT consists of a two-part vertical assembly: a stationary thermal module with a digitally integrated three-zone thermal control system and a motion module with a four-axis motion control system, both of which enable the additive manufacturing of transparent molten glass.
In this setup, the thermal energy needed in the heating system is separated from the mechanical load of the motion system, allowing for greater durability of the overall platform. The print head, located at the interface between the upper thermal and lower motion modules, requires the “highest thermal and mechanical performance from its material choice.”
Moreover, the technology enables industrial-scale production thanks to its high production rate, print accuracy and consistency. These features, MIT emphasizes, were previously unattained in the 3D printing of glass.
Structures printed out of molten glass using the G3DP2 platform are subjected to a thermal soak at 525°C for roughly five minutes. This step offers a temperature buffer between the print stage and the annealing stage, which toughens the final product. Notably, the printer’s build chamber is capable of annealing prints, though the researchers say an external annealing oven can enhance and accelerate overall production.
In addition to presenting its G3DP2 platform in more detail, the Mediated Matter research team also used its study to highlight its architectural-scale 3D printed glass structures in order to evaluate the potential capabilities of the glass printer for industrial production. The structures in question were the set of three-meter-tall glass columns designed and printed for Milan Design Week in 2017.
The columns, made up of 15 printed glass components each, were structurally optimized to perform as freestanding cantilever structures with continuous cross-sectional morphology along their height. The continuous morphology enabled the reduction of stress concentrations at any local point in the columns. The 15 sections of each column were assembled with thin silicone film joinery and steel post-tensioning systems.
Ultimately, the structures demonstrated the ability of the AM technology to produce geometrically complex, accurate, strong and transparent glass structures. “The installation presented here demonstrates the potential of this AM technology to produce freestanding glass structures for the first time at architectural scale. The set of 3-m-tall glass columns manifests their own structural integrity afforded by the novelty and capability of the new manufacturing platform,” the researchers write.
In terms of applications, the G3DP2 technology could one day be used to produce glass tubing for architectural structures, working simultaneously as heating, ventilation and air conditioning (HVAC) systems.
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.”
The full study was published in the journal 3D Printing and Additive Manufacturing and can be found in full here.