Steel beams are pretty uniformly strong, but they're all run of the mill, literally. If you start 3D-printing custom beams for the exact purpose they're intended to serve though, you've got a regular space-age material on your hands. It's lighter than steel and orders of magnitude stronger.
The process, developed byYong Mao of the University of Nottingham, UK and colleagues, isn't just the product of one innovation, but rather a whole bunch of them wrapped up into one bundle. First, you start out withF a hollow beam and you test it with the load it needs to bear. When it inevitably fails, you use some sophisticated software to analyse that sucker and 3D print an internal fractal structure to provide support, kind of like what's inside your bones. Then lather, rinse, and repeat. With each iteration of ever-smaller fractal innards, the beam can gain strength by the order of magnitude, with practically negligible weight gain. Third generation beams, about as far as we can hope to go with current tech, are 10,000 times stronger than steel.
There is one big limitation to how strong you can get with this stuff however, and it all depends on printer fidelity. Since these sorts of beams are specifically designed, there's not much extra support to carry your load, so if the mesh isn't perfect, you could be in trouble. As 3D printers get better however, imperfections won't be a problem on the larger scales, and more and more iterations will be possible, making for structures that are both incredibly strong and incredibly light. Now if only they could figure out how to 3D print some new bones for us. [Physics World]