Materials engineers at MIT have created the carbon fiber equivalent of Lego bricks or K'Nex -- interlocking carbon fiber blocks that can be formed into large structures that are 10 times stiffer than comparable ultralight materials. These structures could be mass-produced by automated robots, and fashioned into airplane and rocket fuselages, wings, and bridges, among other things. Interestingly, unlike almost every other object made from composite materials, objects made from MIT's new structure can be easily disassembled or have individual "bricks" replaced when they break.