WHEN you hear the word “biotech”, it normally conjures up images of agriculture, food production and medicine. You don’t normally think of buildings. Yet biotech is something that can help enhance buildings of the future.
We’re not talking about plants that help to green up a building but the use of fungi and bacteria in building materials to enhance the quality of the structure.
Mycelium, the root network of fungus, grows very easily and over a short period of time. All it requires is some form of nutrient – sugar, for example – from pieces of wood or wood chips, and it will grow very quickly.
It’s like yeast except instead of growing as a single cell, mycelium is multi-cellular and can grow into something quite big. It assembles a network of long, tiny fibres that are very strong. The most typical example of this is a mushroom.
Of course, if you want to use it for building materials, you won’t be looking to grow mushrooms. Rather than allow it to grow into its natural form, the mycelium can be shaped into various structures by controlling the temperature, the amount of carbon dioxide it receives, and the humidity and the airflow around it.
Mycelium's fast-growing fibres produce materials that can be used for packaging and construction. Best of all, the technology to do this is already here so this isn’t something we’re looking at happening in the future. And many academic institutions have programmes that look into incorporating mycelium into construction materials so that they can literally grow over time.
The best example of a mycelium-based structure is the Hy-Fi installation in New York, which was on display in 2014. It consisted of a 13-metre tower made completely out of 10,000 mycelium bricks that were naturally grown from shredded corn stalks and specially-developed mushroom mycelium.
The structure temporarily diverted the natural carbon cycle to produce a building that grew out of nothing but earth, and required no energy and produced no waste or by-products. After three months, the structure was disassembled and the bricks decomposed to compost.
Cracks in a building’s concrete spell trouble. If not fixed, rain would seep in and damage the structure, including causing the steel to rust. A research group at Delft University of Technology is looking to fix that through mixing bacterial spores into the concrete mix. When water seeps into such concrete, it will animate the bacteria which in turns triggers a chemical process causing new calcite crystals to grow and heal the concrete.
Henk Jonkers, project leader at Delft, says what makes this limestone-producing bacteria so special is the fact that they’re able to survive in concrete for more than 200 years and come into play when the concrete is damaged. “For example, if cracks appear as a result of pressure on the concrete, the concrete will heal these cracks itself,” says Jonkers.
One can easily imagine how useful self-healing concrete would be for buildings of the future. Says Benoit Battistelli, the president of the European Patent Office: “This innovation is clearly looking towards the future. Bacterial concrete will extend the service life of bridges, streets and tunnels and give a completely new perspective to concrete production.”
MICROBIAL FUEL CELLS
Most buildings are constantly taking in waste that needs to be removed and treated. How about using such waste to generate energy instead?
That’s exactly what a team of researchers on an EU project called Living Architecture is working on. They hope to develop a new type of microbial fuel cell, which takes domestic waste and generates small amounts of power. These fuel cells would be integrated into the bricks of the building, which take in waste water and bacteria and convert them into energy.
The Living Architecture project aims to transform bathrooms, kitchens and commercial spaces into environmentally-sensitive, productive sites, with wall sections in the rooms being replaced with bioreactors (or self-contained microbial systems). |
One type of bioreactor is a fuel cell that houses anaerobic bacteria to produce electricity and clean water. Another is an algae photo-bioreactor that produces biomass for fuel or food. The third type is a synthetic bioreactor that can make alcohol or other plant-based materials.
A good, practical example of use of microbial fuel cells is the BIQ (Bio-Intelligent Quotient) House in Hamburg, Germany. It is an apartment building that’s the world’s first algae-powered structure.
The two sides of the building have an outer shell where microalgae grow. Sunlight and carbon dioxide combine to produce enough biomass to generate electricity. The translucent tanks that contain the algae also regulate the building’s temperature by absorbing more sunshine as the biomass increases.
The trend today is to create a smart building or smart home. Usually this refers to the Internet of Things (IoT), but a smart building or home could also incorporate biotech to make it smart, ecologically-sustainable and behave like an eco-system of sorts. When you combine biotech with IoT, you have really built a building for the future.
Oon Yeoh is a consultant with experiences in print, online and mobile media. Reach him at email@example.com.