With This Breakthrough, Transparent Glass Can Be 3D-Printed

Glass is an important material with applications in chemistry, biology, optics and photonics. Or for some of us it can help us see, help us take awesome pictures and watch the night sky in detail. For scientists, glass has admirable properties such as transparency, thermal resistance, hardness and chemical resistance, making it a very useful material. Being able to 3D print glass is ideal for laboratories like LLNL which deal with high power lasers that require a large amount of optics. In addition to that, being able to just print transparent glass where the refractive index can be altered could make your trip to the opticians a whole lot easier in the future.

Although, 3D-printing glass has already been done, there are problems with existing methods. For example, some 3D-printed glass can appear opaque due to incomplete densification. Other methods require high temperatures which lead to filaments in the 3D-printed glass which are potentially susceptible to thermal stresses. All in all, existing methods just don’t quite cut it – the glass is opaque, porous and non-uniform structures exist within the glass. Therefore, current 3D-printed glass is just not as good as glass made by conventional methods. With the new technique discovered by LLNL scientists, glass that is ‘transparent, free form, and 3D with sub-millimeter features’ can be produced.

The team at LLNL have developed a novel way to 3D-print glass that is optically transparent. This technique works via a two-step process: printing and sintering. Firstly, an ink with glass particles suspended within it is printed into the desired shape. One of the novelties of this technique is that the glass is printed at room temperature. The object starts off opaque but once the printed object undergoes a thermal treatment, the object densifies and all evidence of printing vanishes. The heating treatment ensures that the glass is optically uniform and transparent. The final step involves putting the glass through an optical quality polish which allows the glass to obtain optical uniformity, which is ideal.