Concrete and steel make up the bulk of today’s skyscrapers and city buildings. But both materials require huge amounts of energy to process, accounting for nearly 10 percent of global carbon emissions. University of Cambridge researchers led by Michelle Oyen are pursuing a solution in the lab: they think materials like bone and eggshell could offer a greener alternative.
Knowing that the production of steel and concrete results in more carbon emissions than air travel, Oyen, a bioengineer, decided to tackle the problem from a new angle, drawing inspiration from nature for new building materials. She works in the field of biomimetics or “copying life.” With US Army Corps of Engineers funding, she’s made artificial eggshell and bone in the lab, materials that could be used for medical implants – or for constructing buildings.
In a press release Oyen said, “What we’re trying to do is to rethink the way that we make things. Engineers tend to throw energy at problems, whereas nature throws information at problems – they fundamentally do things differently…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. If we’re going to make a real change, a major rethink is what has to happen.”
The process to fabricate bone and eggshell happens at room temperature, and thus requires far less energy than processing concrete and steel. Proteins and minerals lend hardness and toughness. The researchers are also working to incorporate natural properties of bones – notably the fact that they can heal themselves – into the lab-made materials. According to the team, their process could be easily scaled up.
But we probably won’t start building with eggshells and bones tomorrow. Oyen’s team is still using animal collagen to make bones and eggshells, though they are looking for a way to use synthetic material, perhaps a polymer or synthetic protein, instead. The construction industry would also have to rewrite building standards to accommodate the new materials.