Could Artificial Bones One Day Replace Steel?
Concrete and steel have allowed us to build some of the most impressive structures on Earth. The industries responsible for manufacturing them also account for nearly one-tenth of the world’s carbon emissions. As both the threat of climate change and our need for urban development continue to rise, scientists at the University of Cambridge’s Department of Engineering are looking into a possible alternative: artificial bones and eggshells.
As Geek reports, the team, led by Michelle Oyen, is using biomimetics—the field of building materials based on elements from nature—to recreate two super-strong materials that occur organically. For their weight, bones are remarkably strong. A comparable bar of steel weighs four to five times as much as a human bone, making bones the stronger material ounce-for-ounce. Eggshells are also capable of supporting considerably heavy loads despite their thin structure.
To recreate these elements in the lab, Oyen and her team are templating layers of minerals onto collagen, the most abundant animal protein on Earth. The mineral components make the structure stiff, while the protein helps it withstand breakage. The artificial bone and eggshell materials are made from different combinations of minerals and protein, and the team recently discovered that the two materials form perpendicularly to one another. This may open the door for growing a lattice hybrid structure that’s stronger than either element individually.
In contrast to all the work that goes into steel production, these materials can be made at room temperature and require much less energy to manufacture. The technology could potentially be used to make medical implants, or it could be scaled up and incorporated into low-carbon construction projects.
"All of our existing building standards have been designed with concrete and steel in mind," Oyen told the University of Cambridge. "Constructing buildings out of entirely new materials would mean completely rethinking the whole industry. But if you want to do something really transformative to bring down carbon emissions, then I think that’s what we have to do."
She’s currently looking into using non-animal–derived or synthetic proteins or polymers as a possible replacement for the collagen in her structures. Mimicking the self-healing properties of bone in building materials is also something engineers are hoping to achieve down the road.