A new kind of steel, inspired by the structure of bone, could go a long way toward making our buildings stronger and saving money. This material is stronger than what we have now, and it might even be able to heal its own cracks.
To create a stronger kind of steel, scientists thought about the design of bones, which are lightweight but (thankfully) don’t crack that easily. This is because, internally, bones are structured like a lattice, with all these different patterns and connections that can resist different forms of pressure being put on them. (This feature is called “hierarchical microstructure.”) So, the researchers engineered steel to be designed in a similar way, according to a study published today in the journal Science.
We use steel in everything from building infrastructure to trains to airplanes. It’s a very common material, but it can only take so much, and, after a while, develops tiny cracks that can cause it to suddenly fracture. Don’t worry: this doesn’t mean that everything is unsafe, just that builders are extra cautious when using steel, which makes it more expensive to build anything with it.
That’s why the researchers were so interested in creating more-resilient steel. This new form of steel is built out of overlapping layers. This means that even if a crack begins in one layer, it might not spread to the other ones. Different parts of the layers have different hardnesses, too, which works together to make the material stronger. This design can even contain a crack to keep it from spreading more.
Of course, you can’t really test this new material in a realistic environment — the risk of danger is too high. But the researchers compared this steel with other types, and found that it was the most resistant to developing the microcracks from repeated use. As with many new materials, it might be a while before we can make a lot of it and before it becomes widely used. The material would be more expensive than regular steel, though it might save money in the end because you’d need to use less of it, the researchers say. But in the meantime, this new structural technique can be helpful for others doing similar research into how to make the things around us stronger and stronger.