New Construction Material Is Lighter Than Water, Stronger Than Steel

Courtesy Jens Bauer/Karlsruhe Institute of TechnologyAnother honeycomb-inspired hexagonal microtruss structure. Compressive loads corresponding to 7823 pounds per square inch may be carried at a density less than half that of water.

Researchers in Germany have made a significant advance in creating lightweight, tough materials by taking a note from bone, wood and honeycombs.

A Karlsruhe Institute of Technology team fabricated polymer and alumina composites in a regular framework structure using 3-D laser lithography. Their hierarchical microarchitecture achieved extremely porous materials with strength-to-density ratios higher than bone, aluminum or steel.

"The novel lightweight construction materials resemble the framework structure of a half-timbered house with horizontal, vertical, and diagonal struts," said Jens Bauer, a microarchitecture expert who lead the research, in a statement.

Their samples contained 45 percent to more than 90 percent air, making them extremely lightweight while also withstanding more than 46,000 pounds per square inch of pressure. They published their work recently in the journal Proceedings of the National Academy of Sciences.

Courtesy Jens Bauer/Karlsruhe Institute of TechnologyCompression test of a polymeric truss structure coated with 10 nm of alumina. It is almost 88 percent air, less than a fifth the density of water and withstands more than 870 psi of pressure.

Courtesy Jens Bauer/Karlsruhe Institute of Technology.Compression test of a polymeric truss structure coated with 10 nm of alumina. It is 66 percent air, less than half the density of water and withstands more than 15,800 psi of pressure.