Printed glass

Many believe that 3D-printed serial components can potentially revolutionise the global economy. Whenever an object is built up layer by layer, using plastic, ceramics, metal or other raw materials, 3D printing has two benefits: on the one hand, complex shapes suddenly no longer need to be optimised for manufacturing purposes, and, on the other, it becomes cost-effective to produce single items.

3D-printed products are a particularly promising option in medical engineering and the pharmaceutical industry. According to a survey by the management consultancy firm Ernst & Young, 28 per cent of companies in twelve – mostly Western – countries have already gathered some experience with additive layer printing. Hearing aids are now almost entirely 3D-printed, and manufacturers also benefit from this new technology in the production of tablets and dental implants. Moreover, market forecasts are showing a rising trend in other industries.

Not surprisingly, therefore, 3D printing is also used more and more in the packaging industry. For the first time researchers have now developed a technically usable 3D printing process for glass. Individual pieces of glass can be produced through an additive layering process for medical, biotech, optical and IT applications. According to the science magazine Nature, this has been achieved by developers at the Karlsruhe Institute of Technology (KIT). Before applying a process called Three-Dimensional Printing of Transparent Fused Silica Glass, Bastian E. Rapp and his team pulverised some quartz glass into particles the size of a nanometre, i.e. 1 millionth of a millimetre. Liquid plastic is hardened as a base material under the impact of light, and the resulting mush is spread thinly on a surface. It is then possible to create any shapes of components, layer after layer.

A similar and equally amazing process had previously been developed by Markus Kayser in 2011. He, too, created 3D-printed glass objects, using sand, after the sand had been transformed into glass under a 3D printing process with the help of concentrated sunlight. At the time, the resulting shapes were still rather rough, and the glass was porous, so that the material was not yet fully transparent.

The researchers from Karlsruhe achieve the required transparency through extremely high temperatures, in a process called sintering. The plastic is burnt, and the fine glass particles are fused. The resulting glass components, says Rapp, will largely be relevant to IT hardware. He believes that, two generations down the line, computers will be using light to perform their work. Instead of electrons, computation will apparently be handled by glass components. This printing process will of course become increasingly attractive to the packaging industry, for example, to make glass ampoules for the pharmaceutical industry.