The world is grappling with various environmental issues like global warming and pollution, and this is how we talk about sustainable buildings. Recently, much research has been conducted on the development of “living materials” for buildings that can combine biology, polymers and cement chemistry to create biomimetic materials that are inspired by nature and can help fight against climate change.
What are living building materials?
Living building materials are also called biological building materials in which microorganisms participate in the manufacture of the material. In this process, bacteria or other microbes function as mini-factories that develop building materials capable of living, multiplying, healing cracks and also absorbing harmful toxins from the air. Note that although wood is a biological material, it is not alive.
How can living building materials fight pollution?
The main function of these materials is to replace conventional buildings that emit carbon emissions. According to studies, cement is the most widely used construction material and one of the biggest sources of industrial pollution. Therefore, if cement can be replaced with living building materials, it can help reduce the environmental impact caused by the construction industry.
How did nature inspire the development of this material?
Scientists are inspired by solutions from nature and organisms such as corals that secrete limestone. One of the finest examples is that of coral reefs formed by colonies of coral polyps held together by calcium carbonate. According to Wil Srubar, materials scientist and director of the Living Materials Laboratory at the University of Colorado at Boulder, “nature has figured out how to do a lot of things smartly and efficiently, we just need to pay more attention to it.”
How are living building materials produced?
Wil Srubar and his team experimented with cyanobacteria belonging to the genus Synechococcus to create building blocks of different shapes. They are photosynthetic organisms that use carbon dioxide, sunlight, and water to grow and make building material. In this way, this new invention will play a key role in absorbing carbon from the atmosphere and mitigating climate change.
Colonies of cyanobacteria are introduced into a solution of sand and gelatin. Under proper conditions, these microbes absorb carbon dioxide which helps them grow and produce calcium carbonate or limestone. A chemical reaction occurs due to which the calcium carbonate mineralizes the gelatin and binds with the sand to create biocement or microconcrete which is a hard living brick.
The most interesting part of this process is that the living brick can reproduce under ideal conditions and become a new brick. Therefore, if these materials can grow biologically, they can be made exponentially. However, a major drawback is that living building materials need humid conditions to survive and cannot multiply in an arid climate.