According tomedia reports, we have heard of the experimental self-healing concrete, which can repair cracks inside it. Now, scientists have used bacteria to create building materials that can grow in the field, and the material can be “regenerated” when broken. The team at the University of Colorado, Boulder, led by Associate Professor Will Srubar, first combined sand with a clear glue gel. The mixture is then placed in a brick mold and blue bacteria are added to the polyglob blue bacteria. The internal structure of the mixture acts as a scaffold in which microorganisms can “inhabit”.
Bacteria begin to grow when they absorb carbon dioxide gas from the surrounding environment and produce calcium carbonate in the process. The latter mineralizes the hydrogel into a mortar that binds the sand particles together to form a solid brick.
In tests conducted so far, the researchers found that after 30 days of brick formation, about 9 to 14 percent of bacterial colonies are still alive – if the bricks are placed in polyglobula- friendly humidity levels in an environment where success is also possible. This is a challenge because when bricks are completely dry, they are the most intense. With that in mind, scientists are now studying microbes that can survive in more arid conditions.
Ultimately, the researchers hope the technology will be useful in building materials that can grow in place from supplied ingredients and have self-healing capabilities.
In fact, experiments have shown that if half of a “fixed” brick is placed in a mold with more gel and sand, half of the bacteria will migrate out and settle in the new material, eventually forming another brick. Eventually, a “mother brick” (initially divided into two pieces) can be used to produce up to eight other bricks.
In addition, building materials made from bacteria will actually help isolate excess carbon dioxide gas from the environment. Conventional concrete is the opposite, as the production of the cement used is one of the main sources of man-made CO2 emissions.
“We’ve used biomaterials in buildings, such as wood, but they’re no longer alive, ” says Srubar. We’re asking: Why can’t we let them survive and let this biology do good things? “
The study was presented in a paper published this week in the journal Matter.