The Living Concrete that Can Grow Itself

Scientists have developed a new ‘living concrete’ that regenerates and can even reproduce on demand. The new material holds great potential for the construction industry with its high-fracture toughness and biological capabilities, meaning new bricks can be ‘grown’ on site. With concrete being the second most used substance on the planet after water, could this new material revolutionise construction as we know it?

The incredible new material, pioneered by scientists at the University of Colorado Boulder, is created by mixing sand with bacteria. The result is a hybridised living building material: strong and structurally stable while dry, it can self-repair cracks and even reproduce entirely with minimal additional resources.

Blocks of Potential

Image courtesy of University of Colarado Boulder

Although the material is weaker than conventional concrete, it is sturdy enough for a person to stand on, and its creators are positive their new discovery could help transform the industry, leading to evermore innovative applications of concrete:

“We already use biological materials in our buildings, like wood, but those materials are no longer alive. We’re asking: Why can’t we keep them alive and have that biology do something beneficial, too?” said senior author Dr Wil Srubar, head of the aptly named Living Materials Laboratory.

“We envision this material could be used as a building block for many applications, including carbon-sequestering mortar, lightweight concrete in buildings, biologically active surfaces, temporary disaster-relief shelters, or roadways.” added Dr Srubar.


The Science

Image courtesy of University of Colarado Boulder

To ensure the bacteria take hold and thrive, a ‘scaffold’ solution is first created by combining sand and a water-based gel. This provides the structure around which the bacteria mineralise and harden – an organic process similar to how seashells form out at sea.

Perhaps the most incredible property of the new hydrogel-sand bricks is their ability to reproduce – a biological function activated by a precise increase in temperature and humidity, effectively bringing the bricks to life. Dr Srubar demonstrated how a ‘parent’ brick can reproduce up to eight bricks after three generations, meaning new materials could be grown on-site and formed into any shape and size, just by adding a little extra sand, hydrogel, and food for the bacteria.

“We’re trying to create something that stays alive. A Frankenstein-type material.”

The team believes the material could be industry ready within five to 10 years and that the technology may provide a platform to work with other forms of bacteria. For instance, similar techniques could be applied to reduce pollution levels by creating living building materials that absorb harmful toxins from the air.


Biology is The Future

Image courtesy of University of Colarado Boulder

There is even talk it could be used in hostile environments with limited resources, such as on the surface of Mars or the Moon. “We believe this material is particularly suitable in resource-scarce environments, such as deserts or the Arctic – even human settlements on other planets.”

“It’s going to happen one way or another, and we’re not going to be trucking bags of cement all the way to Mars. I really do think that we’ll be bringing biology with us once we go. The sky is the limit, really, for creative applications of the technology.”

It's clear that the team at the Living Materials Laboratory has high hopes for this material and its future applications. CCL will be keeping a close eye on its development.