Whilst glass has been available as a material for 3D printing before, the methods used have left the product opaque. Not any more. A team at Massachusetts Institute of Technology (MIT) has managed to create the first optically transparent 3D printed glass.
Printed through a custom nozzle made of aluminium oxide, the glass is extruded layer by layer and the object is built up in much the same way as other extrusion printers.
The main challenge with printing glass this way is the temperature involved. To make glass molten enough to flow, the temperature must exceed 1000°C. The team got around this by creating three separate heated chambers, one for each stage of the process.
First off, the molten glass is stored in a crucible with heating coils to keep it at the desired temperature. Then the nozzle itself is heated to ensure the glass flows through and does not stick to the inside. Finally the build chamber is heated to a temperature just above the melting point of glass. This allows the glass products to cool more slowly and be less prone to breaking.
This is undeniably a breakthrough for the 3D printing world, but there is still work to do. The MIT Glass Labs team are now working towards understanding the design constraints from the printer and studying the optical and mechanical properties of the printed objects. Take a look at the video below from MIT Media Lab to see their pioneering process in action.