Researchers think we might need to live in cities of 'bone'

As our population skyrockets towards 9 billion, a group of researchers in the UK think the only way we can realistically keep up with building demands is to look to materials like artificial bone to construct the cities of the future.

While the idea of living inside a 'bone skyscraper' might sound terrifying, right now, concrete and steel are responsible for 10 percent of worldwide carbon emissions. Instead, natural materials such as bone and eggshell manage to achieve similar strength with far less resources.

A team from the University of Cambridge is now studying these materials further to try and figure out whether we can mimic the process to create our own bone-like materials as efficiently as the human body.

"What we’re trying to do is to rethink the way that we make things," says team leader and bioengineer Michelle Oyen. "Engineers tend to throw energy at problems, whereas nature throws information at problems - they fundamentally do things differently."

Her lab has already created artificial bone and eggshell in the lab in small doses, but the process can be done at room temperature and is cheap, energy efficient, and easy to scale up, she explains.

They do this by taking animal collagen - the most abundant protein in the world - and then simply templating on layers of minerals. 

The 'bone' they've created is pretty much made up of equal portions of mineral and protein - the mineral gives the bone stiffness and hardness, while the protein makes it more resistant to fracture.

The artificial eggshell, on the other hand, has around 95 percent mineral to 5 percent protein, which means it's thinner and lighter, but also more fragile.