Now we are excited to meet aerographite, a sponge grown of carbon nanotubes that's the least dense solid ever: a cubic centimeter of it weighs just two ten-thousandths of a gram.
The substance can also be compressed, sponge-style, by a factor of 30, and it springs right back without losing integrity. It's electrically conductive, which means it may be used in new batteries and supercapacitors; it's also highly resistant to chemical attack, hydrophobic, a terrific insulator, opaque to X-rays -- great stuff.
Here's a video of two black morsels of aerographite dancing in static electricity.
Five amazing, clean technologies that will set us free, in this month's energy-focused issue. Also: how to build a better bomb detector, the robotic toys that are raising your children, a human catapult, the world's smallest arcade, and much more.