Material research and development for 3D printers is probably as important, if not more important than the development of new additive manufacturing techniques. Stronger, lighter materials will let us build more effective components and products, to further satisfy a customer or projects needs. Industries such as the aerospace industry are constantly looking for new materials.
German scientists at the Karlsruhe Institute of Technology in Germany have been using a Nanoscribe laser lithography printer, to develop 3D printed microscopic structures that are less dense than water, but stronger than steel. Phd student Jens Brauer and his team behind the material claims, “This is the first experimental proof that such materials can exist.”
Water has a density of 1000kg/m3 and most solid materials, unless they are porous, are heavier than water (see the chart above for further details). Porous materials tend to be weaker, while solid materials, such as steel, can withstand much higher pressures and forces. There are exceptions, however. Bone and wood have a high tensile strength while maintaining lightweight properties. The team took design cues from the structure of bone and wood to produce a 3D structure with similar properties.
Bauer and his team developed microscopic trusses out of a ceramic material and 3D printing, to create the structures you see above. A coating of aluminum oxide was applied using atomic layer deposition (ALD) to further increase the stiffness of the structures. The teams strongest structure was both lighter than 1000kg/m3 and could withstand pressures of up to 280 MPa, making it lighter and stronger than steel. They achieved this via a honeycomb arrangement and an aluminium coating 50 nanometers thick.
You can find the full paper on the Proceedings of the National Academy of Sciences here.