University Engineer Develops Bio-Bricks
A civil engineering student from the University of Waterloo has recently developed carbon-neutral masonry units with bacteria.
Inspired by a co-op work term as a project manager for construction crews laying asphalt, Adrian Simone told the University that he was concerned about the potential health impacts of the work being conducted.
“I started thinking there has to be a better way to do this,” he recalled.
Currently in his fourth year of the civil engineering program, after Simone completed his co-op work he launched his own research efforts into how recycled aggregate could form masonry units through a natural microbial process.
The resulting material would also have to maintain the same strength and durability as regular bricks.
“The solution came from research on self-healing cement where microbes were used to fill gaps in cracked concrete,” Simone explained. “By readjusting this process, we can create supplies with similar properties and a competitive price that makes the manufacturing process completely sustainable.
“There is a microbial process in which certain bacteria, in the right conditions, can create stone out of easy-to-find minerals. These bacteria are suspended in an aggregate and saturated using these minerals suspended in water.”
The university went on to note that the resulting material tackles two industry problems: reducing carbon emissions and removing the need for new raw materials in a carbon-neutral solution.
Industry Support, Upcoming Competition
Since his discovery, Simone co-founded startup MicroBuild Masonry to submit what are now called “Bio-Bricks” into the 2022 James Dyson Award competition.
Rania Al-Sheikhly, a master of business, entrepreneurship and technology (MBET) student at Waterloo is the other co-founder of MicroBuild Masonry. In previous competitions, Al-Sheikhly shared that the university had enjoyed success in pitch contests through the Velocity incubator and the Conrad School of Entrepreneurship and Business.
Recently, Simone’s bricks were announced as a national runner-up in the contest. The innovative material will now go up against other student inventions from 28 other countries for two top prizes of US $45,000.
A short list of 20 international finalists is slated to be announced in October from an initial field of almost 1,700 entries.
“Having exposure on this level is incredibly helpful,” Simone said of its success so far in the Dyson contest. “It tells us that what we are doing is something that people are interested in learning about and that can lead to a lot more opportunities.”
The Dyson competition was launched by James Dyson, inventor of the popular bagless vacuum cleaner, to challenge university students to develop innovative products that solve problems.
“Young design engineers have the ability to develop tangible technologies that can change lives,” he said. “The James Dyson Award rewards those who have the persistence and tenacity to develop their ideas.”
Other Bio-Brick Research
Back in 2018, researchers from the University of Cape Town’s civil engineering program created the first bio-brick grown from human urine. According to Dyllon Randall, a senior lecturer in water quality engineering, the bricks were created through a natural process called microbial carbonate precipitation, which is similar to how seashells are formed.
Not only do the bio-bricks produce less carbon dioxide (they are made in molds at room temperature instead of being kiln-fire), but their byproducts (nitrogen, phosphate and potassium) can also be used as components for commercial fertilizers.
Those fertilizers are produced as part of the phased process used to make the bricks, the university said, ultimately resulting in a zero-waste process.
The next question for the researchers would be how to optimize the process and make it profitable with the obvious logistic hurdle of urine collection.
Some years later, in 2020, researchers from the University of Colorado Boulder published a study in the journal Matter describing a new approach to designing more sustainable buildings.
In the publication, engineer Wil Srubar and his team outlined the strategy for using bacteria to develop building materials that “live and multiply.”
The crux of the research was cyanobacteria. Under the right conditions, the university says, the microbes absorb carbon dioxide and grow to make calcium carbonate.
In terms of manufacturing, the researchers add cyanobacteria into a solution of sand and gelatin. The calcium carbonate mineralizes the gelatin, which binds with the sand and creates a brick. This process also removes carbon dioxide from the air, as opposed to creating it like the manufacturing of standard bricks.
The team’s research included strength tests and found the “living bricks” to have the same strength as regular mortar.
And in March 2021, scientists from Montana State University were reported to be working on sustainable alternatives to concrete, focusing on microorganisms. MSU’s Center for Biofilm Engineering, Assistant Research Professor Erika Espinosa-Ortiz led the charge, along with Mechanical Engineering Professor Chelsea Heveran.
At the time, the team received a half-million-dollar grant from the National Science Foundation and was experimenting with an approach that would allow bacteria to grow within the materials, sort of like a fibrous scaffold.“We have tested these with bacteria, and we are in the process of testing with the fungus,” Espinosa-Ortiz said. “We fill the syringes with sand. We have all sorts of different kinds of sand. This is coarse sand and then fine sand.”
Tubes were attached to either side of the syringes, through which researchers pumped in a liquid that includes a fungus. The fungus then spread into branched networks known as mycelium. The calcium and bacteria activate a chemical reaction to form calcium carbonate, the main mineral found in seashells and pearls, which is the center of the research.
“Once I break that cement into pieces, I have very, very limited ability to reuse those pieces for anything else, and I can’t grind it back down and just pour it as new cement. The neat thing about calcium carbonate is that we can potentially break that down and use it as new inputs into other building materials,” Heveran said.
For this project, which was estimated to take about two years, the team focused on creating blocks and that be glued together with a biocement, taken apart and then reassembled.