Engineers have created the world's lightest material. It's called a microlattice and is made of tiny metal tubes crisscrossed to form a mesh. "The trick is that the tubes are hollow," says Lorenzo Valdevit, an engineer at the University of California, Irvine. That makes the structure 99.99 percent air.
The material is formed by coating a plastic model of the structure with a thin layer of nickel alloy, or a mixture of metals. The plastic is then dissolved away from the inside, leaving behind empty metal tubes. "The walt of each tube is only 1/1000th the thickness of a human hair," says Valdevit. The lightweight and spongy flexible structure is perfect for use in batteries and shock absorbers.
DENSITY OF MATERIALS
The world's lightest material has a density (mass over volume) of 0.9 milligrams/ [centimeter.sup.3]. About how many times lighter is it than Styrofoam?