3D-printed glass breakthrough

GLASS is an invaluable material for industry and research due to its transparency, thermal stability and resistance to acids.

Now, for the first time, researchers have been able to use a household 3D printer to create tiny structures that retain all these properties.

Glass is a widely-used, high-performance material. It has unmatched optical transparency, outstanding mechanical, chemical and thermal resistance and insulating properties. However, shaping it can be difficult – especially when a high-purity product such as fused silica glass is required, or when microscopic structures are needed.

Due to this difficulty, glass has been inaccessible to modern manufacturing technologies such as 3D printing. Previous attempts to 3D print glass structures have either resulted in the loss of functionality of the material or required very high-temperature extrusion processes. For example, melting glass and applying it via a nozzle results in a rough surface and porous internals.

However, a team of researchers at Germany’s Karlsruhe Institute of Technology (KIT) have demonstrated a novel, innovative additive manufacturing method capable of producing smooth, clear high-quality glass structures.

In their technique, nanoparticles of high-purity quartz were mixed with a small quantity of liquid polymer. This was then cured by light at specific points using stereolithography, before the liquid material was washed out in a solvent bath. What remained was a cured structure that still contained the polymer. To remove this and fuse the glass particles, the researchers used a final heating step.

Bastian Rapp, who led the project, said: “The material of the pieces manufactured was high-purity quartz glass, with its respective chemical and physical properties. The glass structures showed resolutions in the range of a few thousandths of a millimetre, but it is also possible to have dimensions in the range of a few centimetres.”

Their additive manufacturing technique is the first time glass has been printed at room temperature, and can be undertaken on a commercially-available 3D printer. Rapp said: “It’s a well-established technological platform in terms of machinery, and it’s a well-recognised and well-known material. The only thing we made was the bridge in between.”

The potential applications for this technology are widespread. For example, in the fields of biology and medicine, very small analytical systems could be made out of miniaturised glass tubes. Optical uses could include producing high-quality lenses for smartphones or even printing optical processor structures for future computers. Rapp has created a company to commercialise the technique and hopes to release a first product by the end of the year.

Nature: http://doi.org/b55v