What’s Strong as Steel and Lighter than Water?
Courtesy Lucas Mearian, ComputerWorld.com
An example of the nanostructures created with 3D laser lithography (Source: Karlsruhe Institute of Technology)
Computerworld – A team of German scientists used 3D laser lithography to print microscopic trusses and shells that are as strong as steel — and lighter than water.
The objective of the research is to someday create materials stronger than anything yet produced, yet lightweight enough for use in products such as aircraft or armor.
The honeycomb-like structures, made of ceramic-polymer composite material, are only about 50 nanometers thick. A nanometer is one billionth of a meter.
To give you an idea of how small the microarchitectures are, consider that a strand of human DNA is 2.5 nanometers in diameter and a human hair is about 80,000 to 100,000 nanometers wide.
The German team recently published a paper on their research.
The "polymer composites … exceed the strength-to-weight ratio of all engineering materials, with a density below 1,000 kilograms per meter (kg/m)," said Jens Bauer, a materials scientist leading the research at the Karlsruhe Institute of Technology in Germany, in the paper.
The Nanoscribe Photonic 3D Professional printer from Nanoscribe GmbH, is a table-top laser lithography system used for creating three-dimensional photonic structures (Source: Nanoscribe)
The scientists took their inspiration from nature, which has produced materials far stronger, yet less dense than those created in a lab. For example, natural cellular materials such as bone and wood are strong and yet have considerably lower densities than aluminum alloys, Bauer stated.
The team used a 3D printer from Nanoscribe GmbH to create the nanostructures they hope can someday enable the creation of super-strong materials.
"Applying 3D laser lithography, which allows for producing almost arbitrary structures with sub-micron resolving power, micro-truss and -shell structures may be manufactured," he stated in a recently published paper. "Ratios comparable to those of advanced metallic alloys or technical ceramics have been obtained."
The nanostructures are created by placing a small amount of photocurable resin on a glass slide. Then a stereolithography 3D printer projects a laser in a grid-like pattern on the liquid material, hardening it where the light strikes. The resulting hardened structure is then coated with alumina, or aluminium oxide.
Nanoscribe’s stereolithography 3D printers are unable to as yet create structures larger than micrometers in size.