Can newer 3D printers print with glass

New process enables 3D printing with glass

The material glass was previously not considered suitable for 3D printing. The Karlsruhe Institute of Technology has now developed a new type of process with which complex shapes can be produced from glass using 3D printing.

Three-dimensional printing enables the production of particularly small and complex structures - even in small series. Glass, as one of the oldest materials known to mankind, offers new application possibilities in manufacturing and research, for example in optics, data transmission and biotechnology, thanks to features such as transparency, heat resistance and acid resistance in 3D printing. With the process developed by the Karlsruhe Institute of Technology (KIT), glass can be used for this technology for the first time. KIT will present the new 3D printing process with glass as well as other technological innovations at the Hanover Fair in Hall 2 at Stand B16.

Using glass for modern manufacturing technology

An interdisciplinary team at KIT led by mechanical engineer Dr. Bastian E. Rapp developed. The researchers proceed as follows: First, nanoparticles of high-purity quartz glass are mixed with a small amount of liquid plastic. This mixture is then cured at certain points by light using stereolithography. The material that has remained liquid is washed out in a solvent bath, which means that the desired, hardened structure remains. The plastic still in this glass structure is removed by heating.

"The shape initially resembles a sand cake, it is shaped, but unstable, which is why the glass is sintered in a final step, i.e. heated to the point where the glass particles fuse together," explains Dr. Bastian Rapp, who heads a working group at the Institute for Microstructure Technology at KIT that includes chemists, electrical engineers and biologists. The scientists present the process in the journal Nature under the title “Three-Dimensional Printing of Transparent Fused Silica Glass”.

New method revolutionizes material processing

The different techniques of 3D printing have so far been suitable for the use of plastics or metals, but not for glass. If it was processed into structures, for example by melting it and applying it using a nozzle, its surface became very rough, and the material was also porous and contained cavities. “We are introducing a new method that represents an innovation in material processing. The material of the manufactured piece is high-purity quartz glass with its corresponding chemical and physical properties, ”explains Rapp. The glass structures produced by the scientists have resolutions in the range of a few micrometers - one micrometer corresponds to a thousandth of a millimeter. According to Rapp, the dimensions of the structures can be in the range of several centimeters.

An application example for 3D-shaped glass is data technology. “The next generation but one will calculate with light, which requires complex processor structures. With the help of 3D technology, for example, small, complex structures can be produced from a large number of very small, differently oriented optical components,” explains Rapp. In biological and medical technology, for example, the smallest analysis systems could be made from miniature glass tubes. In addition, it would be possible to use 3D-shaped microstructures made of glass in a wide variety of optics applications, from spectacle lenses with special requirements to the lens of a camera in notebooks.

The development of the researchers around the head of the junior research group, Bastian E. Rapp, is a result of the “NanoMatFutur” promotion of junior researchers, with which the Federal Ministry of Education and Research (BMBF) supports the development of material innovations for industry and society. The work of the research group led by Rapp has been funded by the BMBF for a total of four years with around 2.8 million euros since 2014. (Stefan Girschner)

The original article about the new printing process was published in the journal Nature with the title "Three-Dimensional Printing of Transparent Fused Silica Glass". Authors: Frederik Kotz, Karl Arnold, Werner Bauer, Dieter Schild, Nico Keller, Kai Sachsenheimer, Tobias M. Nargang, Christiane Richter, Dorothea Helmer and Bastian E. Rapp. DOI: 10.1038 / nature22061