Microlattice

...the "lowest-density material" ever.  Pretty amazing!  This is how it's made:

The lattice is constructed through several steps, Carter said. First, beams of ultraviolet light shine through a holes in a mask into a reservoir containing a resin that forms polymer fibers when the light hits it. The fibers follow the path the light takes, and using multiple beams creates multiple interconnected fibers.
Next, the rest of the resin is washed away, the polymer fibers are coated with a very thin layer of nickel, and the polymer fibers are then dissolved, leaving only the metal lattice.