HRL Laboratories collaborating with researchers at Caltech and UC Irvine have developed the lightest metal material yet: it's called microlattice, and it is just what the aerospace industry needs. Microlattice can sit on a dandelion and not crush the seeds, yet it can bear a 50% compression stress load. It's secret is a series of tubes.
The key structural component is a series of hollow tubes. In a study published last November in Science, the researchers exposed a light sensitive liquid to UV light through a patterned mask, which created a three-dimensional photopolymer lattice. They then deposited a layer of nickel-phosphorous onto the polymer lattice, which was then etched. The remaining structure was a macroscopic material with hollow tubes as the base structural elements. The resulting material had a density of .9 mg/cm3. By comparison, ultralight silica aerogels are 1 mg/cm3.