Next Big Thing

3D Printer: Powdered Glass or Silica Sand? Sep 16, 2015

3d printers have revolutionized the engineering and manufacturing industries as well as disrupting virtually every other one. Now they have added another tool to the list of materials they can use: glass.

While some groups have used powdered glass or silica sand, researchers at MIT’s Mediated Matter Group, led by Neri Oxman have developed a 3D printer that extrudes molten glass.
Even though the technology is surprisingly similar to the glassmaking techniques that were first developed 4500 years ago, it represents the first time that 3D printers have been able to produce optically transparent glass using a extrusion 3D printer.

“The project synthesizes modern technologies, with age-old established glass tools and technologies producing novel glass structures with numerous potential applications,” says the announcement on the mit.edu website. The new technique, which has been called G3DP, for Glass 3D Printing, is able to to produce beautiful glass objects that were not only impossible to build previously, the addition of molten glass to the manufacturing toolkit open doors to a myriad of practical applications.

Glass has many advantages over the traditional materials that were able to be used for printing. Not only is it an extremely hard material, it is extremely affordable and available to anyone since glass is essentially made from silica sand, soda ash and limestone. Working with molten glass is tricky under the most controlled of situations, especially as the size of the object that is being created increases. Glass needs to be cooled slowly so the temperature of the interior of the object stays as close to the exterior temperature as possible, also known as annealing.
The team accounted for this by building an annealing process chamber for the glass to be printed into, allowing them to control the temperature more closely.

“The lower chamber acts as an annealer: it keeps the glass warm and it cools it down slowly to release the stresses,” explained Giorgia Franchin, one of the researchers with Mediated Matter Group. The device melts glass beads in an 1,800-watt crucible and gravity feeds the molten material through a 1cm-diameter nozzle. This relatively large nozzle size coupled with the size limitations of the annealing chamber limit the applications of the current models, but future models hope to increase the potential of the technology.
Not only are lab researchers excited about the ability to create their own glass lab equipment, but the green construction industry is already excited about the new building designs this technology makes possible.

Neri Oxman, one of the project’s leader researchers, said that the technique could quickly be used to create “aerodynamic building facades optimized for solar gain”. While there haven’t been any official announcements as the commercial applications, it will only be a matter of time before the technology opens the window of opportunity for researchers, engineers and architects to apply this new tool their fields.