HOW DO YOU 3D PRINT GLASS?

Summary from the TLDR newsletter

Researchers at the University of Notre Dame in Indiana are working to adapt artisan glass-blowing techniques to a robotic platform. They have developed a technique that uses a laser to heat the surface of a glass rod so it can be deformed to create 3D shapes. It is able to create the transparent solid structures needed in optical, microfluidic, and photonic devices. The method can deposit glass at 15 cubic millimeters per second. A picture of the glass 3D printer is available.