3D printed everything from shoes to aircraft components

German scientists have used 3D printing technology to print some very fine and complex objects with glass, including a pretzel. This technology may be used in the future for more useful 3D printing, such as composite lenses, filters, and even decorative objects that usually require highly skilled craftsmen to make.

According to a study published today in Nature, researchers use a "liquid glass" to make complex shapes that are smooth, transparent, and extremely high-resolution. More importantly, these glass items are made using standard, ordinary 3D printers. But this technology also requires the use of a high-temperature stove, which you may not need when you bake at home. Regardless, this study opens up the possibility of using one of the most revolutionary technologies of our time to make very important materials.

Today, 3D printers can be used to make everything from shoes to aircraft components. Of course, the materials used are different, usually plastic, but sometimes metal and ceramic are also used. Glass has some quite unique properties, high hardness, durability, heat insulation, and insulation, and it is the key material for manufacturing high-quality lenses used in glasses and cameras. But this material is difficult to use for 3D printing because it melts at extremely high temperatures.

"Glass is one of the oldest materials known to man, and it has been ignored by the 21st century 3D printing revolution," said Bastian Rapp, a researcher at Karlsruhe Institute of Technology.

Scientists have also previously 3D printed glass objects. MIT scientists have made transparent glass objects using a special 3D printer that can raise the temperature to 1900 degrees Fahrenheit (about 1038 degrees Celsius). Scientists in other places have also made attempts in this area. As a result, the manufactured glass articles have low strength and poor transparency. However, Leiper said that the technology mentioned in the research report published by Nature magazine today is somewhat different, because the 3D printing technology it uses is already very popular.

The secret is the material used by Lepp and his team. The "liquid glass" they use is a mixture of glass powder and liquid polymer. Here's how it works: Standard 3D printers use liquid glass to print items. Then put the object in a high-temperature furnace for processing, and the glass particles will fuse together and become transparent. Researchers have used this technology to make many items, such as castle gates, pretzels, and honeycomb structures in the millimeter series. If you use a higher resolution 3D printer, the resolution of items made with this technology will also be higher. These items can also withstand high temperatures of 1472 degrees Fahrenheit (about 800 degrees Celsius).

"This allows us to use an oldest machining material with the most amazing optical, mechanical and physical properties to give it an artistic appearance under the treatment of modern 3D printing equipment. Our goal is to fill the material gap."

Laip said the technology could be used in the future to 3D print composite lenses in smartphone cameras and components for next-generation microprocessors. But its application potential is really limitless, from glass decorations to glass panels of various complex shapes used in buildings.