A metallic microlattice is a synthetic porous metallic material, consisting of an ultra-light metal foam. With a density as low as 0.9 kg/m³ (0.00561 lb/ft³), it is one of the lightest structural materials known to science. It was developed by a team of scientists from California-based HRL Laboratories, in collaboration with researchers at University of California, Irvine and Caltech, and was first announced in November 2011. The prototype samples were made from a nickel-phosphorus alloy. In 2012, the microlattice prototype was declared one of 10 World-Changing Innovations by Popular Mechanics. Metallic microlattice technology has numerous potential applications in automotive and aeronautical engineering.