For more than a century, humans have built structures with sand and gravel. Inorganic. Lifeless. Carbon dioxide-intensive and environmentally unfriendly.
But what if buildings could come alive instead? What if they were constructed with hybrid materials that exhibit both structural and biological function? A building that could heal itself rather than decay? A structure that would reduce atmospheric carbon rather than contribute to it?
This futuristic vision drives Civil, Environmental and Architectural Engineering Professor Wil Srubar, whose lab has been developing a variety of next-gen building materials inspired by nature. His research has shown that particles like sand can provide the rigid framework for a biological component like bacteria to grow and thrive. Combine the two and you end up with a living material that has not only a structural load-bearing function, but also a beneficial biological one.
“We use bacteria to help grow the bulk of the material needed for construction,” Srubar said. “We know bacteria grow at an exponential rate, so rather than manufacturing bricks one-by-one, you may be able to make one brick and have it split into two, then four and so on. That would revolutionize not only what we think of a structural material, but also how we fabricate structural materials at an exponential scale.”
The project centers around cyanobacteria, a species of photosynthetic saltwater bacteria that can sequester carbon dioxide. By placing genetically-altered versions of these bacteria into the building material to create “bio-bricks,” the researchers lowered carbon emissions compared to traditional manufacturing materials and lent their creations the ability to self-heal from damage.
For the first time we are questioning the paradigm of cementitious materials, and that is incredible because cement technology hasn’t changed in 100 years.” –Wil Srubar
Srubar, a faculty member in the Materials Science & Engineering Program, said the possibilities for his work are endless and especially interesting in extreme environments and military applications. Bricks could regenerate after natural disasters, for example, or act as alarms by changing color when there are toxins in the air.
He feels as though his lab is truly innovating a new field despite being deeply rooted in fundamental disciplines.
“For the first time we are questioning the paradigm of cementitious materials, and that is incredible because cement technology hasn’t changed in 100 years,” Srubar said. “While we are still some years away from seeing a true application, we do feel we are creating this new discipline.”