Boeing has revealed the world’s lightest metal structure, which it claims is 99.99% hollow.The revolutionary breakthrough claims to be 100 times lighter than Styrofoam and could be the future for aeronautical design, and is so light that is can sit atop a dandelion.Called a microlattice, it is so strong the firm says an egg wrapped in the material would survive a 25 story drop .It is a 3D open-cellular polymer structure made up of interconnected hollow tubes, each with a wall 1,000 times thinner than a human hair.