Materials science: How to print glass

Fused silica glass has long been known for its excellent optical properties, yet processing and patterning this material still requires high-temperature processes and/or hazardous chemical materials. To simplify such processes, Bastian Rapp and colleagues have been developing a system—termed 'liquid glass'—in which a viscous amorphous silica nanocomposite can be patterned into complex shapes by moulding and then photocured to produce optical-quality glass structures. In their latest development, the group have tuned the properties of their nanocomposite to facilitate its use in a 3D printer, yielding high-optical-quality glass structures with features as small as a few tens of micrometres.