Made-to-order materials: Engineers focus on the nano to create strong, lightweight materials
(Phys.org) —The lightweight skeletons of organisms such as sea sponges display a strength that far exceeds that of manmade products constructed from similar materials. Scientists have long suspected that the difference has to do with the hierarchical architecture of the biological materials—the way the silica-based skeletons are built up from different structural elements, some of which are measured on the scale of billionths of meters, or nanometers. Now engineers at the California Institute of Technology (Caltech) have mimicked such a structure by creating nanostructured, hollow ceramic scaffolds, and have found that the small building blocks, or unit cells, do indeed display remarkable strength and resistance to failure despite being more than 85 percent air.