Inspired by nature.
Humans often look to nature to solve real world problems through biomimetics — from the Latin for “imitating life”. After all, natural selection has generated numerous incredible, well-adapted structures and materials over the course of evolution.
Scientists are now drawing inspiration from nature to build the cities of the future, with the goal of supporting an ever-expanding population, while keeping carbon emissions under control.
The cities of today are built with concrete and steel, which are unsustainable materials because they get processed at extremely high temperatures that require a lot of energy. Bioengineers like Michelle Oyen from Cambridge University are searching for environmentally friendly solutions.
“What we’re trying to do is to rethink the way that we make things,” she says in a press release. “Engineers tend to throw energy at problems, whereas nature throws information at problems — they fundamentally do things differently.”
In her lab, Oyen is constructing small samples of artificial bone and eggshell, which could eventually be scaled up and used as low-carbon building materials.
The minerals in bone and eggshells give them their stiffness and hardness, while protein (present in smaller amounts in eggshells) offers resistance to fracture. Though bones can break, it is relatively rare, and they are able to self-heal — another feature engineers are trying to reproduce with biomimetic materials. Even eggshells are remarkably tough considering how thin they are.
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Scientists believe mixing artificial bone and eggshells could make a material that is even stronger.
Because the process of making these artificial materials in the lab — which involves ‘templating’ the mineral components directly onto collagen, the most abundant protein in the animal world — is done at room temperature, it requires very little energy.
But it still might be a while before we are living in bone and eggshell houses.
One problem is that the collagen needed to make these materials comes from animal sources. Non-animal-derived or synthetic collagen would be required to scale up production to the point where it could be used as a building material.
As Oyen explains, another major stumbling block is that the construction industry is a conservative one. With existing building standards designed with concrete and steel in mind, 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 says. “If we’re going to make a real change, a major rethink is what has to happen.”
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