German scientists have developed a new technique that allows glass to be used for 3D printing. Despite many innovative breakthroughs at the US-based MIT, among others, no optimal way had been found for this until now.
Glass is known as one of the best materials. Thermal, mechanical and chemical resistance combined with unmatched optical properties make glass a very suitable material for many applications. Yet processing of the material has seen little progression over the past century.
Chemical
Until now, glass could only be processed either at a high temperature or through chemical processes involving dangerous chemicals or gases. This is the main reason polymers are often preferred to glass; they are very easy to process, cast and form into all kinds of arbitrary shapes. A similar process for easily forming glass would be a huge breakthrough.
The technique developed at the NeptunLab of the Karlsruhe Institute of Technology (KIT) is called True3DGlass and is a completely new approach to creating 3D structures from molten glass. The basis of this technique is a 'liquid glass', a mixture of quartz glass powder and liquid polymer. This honey-like syrup can be poured into the 3D printer as ink after which the printer (a standard SLA or FDM 3D printer) prints the desired shape. The object is then placed in a hot-air oven where all the excess material is melted away. What remains are tiny glass particles that mix together to become transparent.
Data technology
The variety of 3D printing techniques available so far have been used on polymers or metals, but never on glass. Where glass was incorporated into structures, for example by melting and applying through a nozzle, the surface turned out to be very rough, the material porous and moist. "We present a new method, an innovation in material processing, where the material manufactured is high-quality quartz glass with the respective chemical and physical properties," explains research leader Dr Bastian Rapp.
3D-shaped glass can be used in data technology, for example. "The next generation of computers will use light, which requires complicated processor structures; 3D technology can be applied, for example, to make small, complex structures from a large number of very small optical components of different orientations." For biological and medical technologies, very small analytical systems can be made from miniature glass tubes. In addition, 3D-shaped microstructures of glass can be used in a variety of optical fields, from glasses that need to meet special requirements to lenses in laptop cameras.
The new technique was presented by KIT at the Hannover Messe (from 24 to 28 April).
By: Kelly Bakker
Source photo: KIT
