World's Lightest Material

In November researchers showed off the lightest material ever created: 
a strong metal mesh about 25 percent less dense than the wispiest aerogel, a foamlike material that was the 
old record holder. A brick-size piece of the new mesh would weigh less than a paper clip.
Faced with a U.S. Department of 
Defense charge to manipulate well-known materials in new ways, Alan Jacobsen, a research scientist at HRL Laboratories in California, constructed delicate lattices of polymer fibers 
less than a millimeter thick. He then coated the lattices with nickel and dissolved the polymer, leaving behind the spindly metal mesh.
Surprisingly, minimizing weight does not mean sacrificing strength and resilience. “I was playing with it, marveling at the weight, and I squished it between my fingers,” materials scientist Tobias Schaedler says. “It bounced right back to its original size.” The lattice can recover after being compressed to half its volume. The mesh’s low weight and high durability, Jacobsen says, make it promising for use in airplane wings and automobile shock absorbers.