According to a paper recently published in the journal Matter, bacteria have been used to create building materials that live, multiply and cut the carbon footprint of construction.
“We already use biological materials in our buildings, like wood, but those materials are no longer alive,” said Wil Srubar, assistant professor of Civil, Environmental and Architectural Engineering at the University of Colorado Boulder and author on the paper.
In Srubar’s lab, all of that has changed.
According to reporting by the University of Colorado, Srubar and his fellow researchers have been using the bacteria Synechococcus, a green microorganism that absorbs carbon and produces calcium carbonate, to create a new kind of brick.
In experiments, researchers inoculate preformed blocks of sand and gelatin with Synechococcus. As the bricks age, the bacteria begin to colonize the gelatin binder of the brick structure, transforming the form into a solid mass of mineralized calcium carbonate and sand. The result is a construction material that is as strong as mortar with the added bonus of being a carbon sink.
Although Srubar’s bio-brick design is still in the nascent stages of development, the engineer has big dreams for this living construction material.
Given that the catalytic element of the bio-brick is a living, growing bacterial colony, the Colorado team believes that by engineering Synechococcus, it will be able to create a building material that can heal itself if it fractures, and possibly grow, lending the labor of building to a biological process that has developed over millions of years of evolution.
“We know that bacteria grow at an exponential rate,” Srubar said. “That’s different than how we, say, 3Dprint a block or cast a brick. If we can grow our materials biologically, then we can manufacture at an exponential scale.”