What Is the World’s Lightest Metal?

In 2015, Boeing announced the creation of the lightest metal ever, a microlattice material that the aerospace company describes as being 99.99% air. It was developed by HRL Laboratories, a joint venture between Boeing and General Motors, in collaboration with Caltech and UC Irvine. The microlattice weighs only about one-tenth as much as carbon fiber, and is said to be slightly lighter than air itself.

The material will probably be used first on space rockets that Boeing plans to build in the near future. After that, it’s expected to be incorporated into the design of commercial airplanes. When the cost of manufacturing comes down, it may be feasible for use in automobiles.

Like floating on air:

• Boeing describes the metallic microlattice as an "open cellular polymer structure." The material would be ideal for structural components, such as sidewall or floor panels of planes.
• Microlattice looks like a sponge, or a mesh, and is simultaneously flexible and strong.
• The breakthrough’s bottom line: A lighter aircraft requires less fuel, which is an airline’s largest expense.