“Good buildings come from good people, and all problems are solved by good design.”
Stephen Gardiner

Years ago, when I was in graduate school, an IT technician was repairing the lab internet. He asked me, “So when will we be able to grow cars?”  The first thing that popped into my mind was how complex a modern car is.  According to Toyota, a modern car is made up of 30,000 parts if you count down to the bolts.  Electric vehicles don’t have as many “parts” according to an article in Handelsblatt Today, an electric car has 200 parts while a gas or diesel car has more than a 1000 parts.  I answered, “It will be quite some time before we can grow a car.  There is still a lot of work to do.”

It might seem strange to ask “about growing cars”; however, writers fill science fiction with the unbelievable.  In the television show Earth: final conflict, the alien Taelons grew buildings. The Leviathans are living spaceships in the television series FarScape. While a science fiction show is not the best barometer for what is possible, it’s not a measure of the imposable either.  When the television show Star Trek debut in 1966, most of the technology seemed imposable.  However, a lot of “Star Trek” technology exists now.  Google translate, while not perfect, makes a passable universal translator.  We also have handheld communicators (cell phones) and tablet computers.  There is even a subset of 3D printers that focus on food (the replicator.)

Technology tends to make truth out of our imagination. That technology is often driven by challenging scientific endeavors.  One of the most complex scientific efforts currently being pursued is sending people to Mars.  One of the biggest problems is providing astronauts with safe housing.  Beyond the extremely thin atmosphere on Mars, the surface of the planet has two other significant issues, the temperature, and the surface radiation.  The average daily temperature of Mars is -81° F (-63° C).  While the average yearly surface radiation on Mars is eight rads, on earth, its 0.63 rads.

The surface of Mars is lethal to astronauts.  Currently, the “best” idea for providing protective habitats for astronauts is to bury the habitat under several feet of Martian soil.  The Martian soil would provide insulation and protect against radiation.   However, burying the habitats would require large equipment so that the astronauts can move large quantities of soil. Alternatively, we could send prebuilt habitats with walls that are highly insulated and resistant to radiation.  The exact thickness and weight of the habitats would depend on the material used.

The biggest problem with these ideas is the weight. Either the habitat or the equipment to build the habitat weighs a lot.  It is both expensive and difficult to transport heavy objects.  According to NASA, it currently costs $10,000 per pound to put an object into earth orbit.

So, what does science fiction technology, questions about growing cars, and visiting Mars have to do with each other?  Well, science is again working towards making science fiction reality.  NASA scientists are researching the possibility of using fungus (mushrooms) to grow buildings.  When we think of fungus, especially mushrooms, what you generally picture is just a small part of the whole organism, the fruiting body.  The fruiting body of the mushroom produces mushroom spores and allows the fungus to spread.

The bulk of the mushroom grows underground or inside a decaying log and is called the mycelium, which is a fibrous material composed of hyphae fibers.  The idea is that engineers will seed lightweight shells with spores and dried food.  Then when the structures reach their destination water, collected from the local environment would activate the spores, which grow filling the shell creating rigid, durable, and insulated buildings.

When the building is full-grown, withholding water and nutrients will stop the growth.  Later if the structure is damaged, astronauts can add water and nutrients, and the building will repair itself. Using biologicals materials like funguses to build buildings would have an additional advantage for places like Mars.  If you want to expand a building, add another shell filled with water and nutrients, the mycelium from the old structure will grow into and fill the new one.

The final advantage of biological buildings is that once they are no longer needed or reach the end of their life, they can be composted and used to either make new buildings or grow crops.  Reusing the fungus as nutrients will reduce the production of waste materials and make the site more efficient.

Additionally, using techniques like CRISPR, the Mycelium could be engineered to secret natural resins or rubbers, turning them into complex composite materials. It is even possible that eventually, we could engineer the fungus to grow into specific shapes.   Imagine a giant puffball mushroom engineered to grow into a hollow sphere 10-12 feet in diameter.

In addition to using fungus, other groups are exploring the use of other organisms to build buildings.  A group out of the University of Colorado at Boulder has developed a method using cyanobacterium.  The researchers’ mix cyanobacterium, gelatin, and sand together into a brick-shaped mold.  The bacteria grow into the gelatin, where it uses light and CO₂ to produce calcium carbonate.  The result is a rigid cement-like brick after all calcium carbonate is one of the components of cement. 

Additionally, the bricks can heal themselves if cracked or even reproduce themselves if broken in half.   The researches cut bricks in half placed half back in the mold with more gelatin and sand, and the bacteria reformed the brick.

While I don’t expect to be living in a house, I grew myself anytime soon. It is starting to look like science will again make science fiction a reality.  While most of what scientists are developing is for use in resource-poor areas like the moon or Mars. We will see offshoots of this technology in use here on earth.  For instance, the bricks created by cyanobacterium absorb CO₂ from the environment, unlike regular cement, which produces CO₂.

Additionally, the company Basilisk out of the Netherlands is already selling self-healing concrete, which uses calcium carbonate producing bacteria.  For schools and universities, there is a tremendous research opportunity.  While researchers have established the basic idea behind biological building materials, there is still a lot to learn.  For example, there are large numbers of microorganisms that deposit minerals, which ones work best.  Does a mix of multiple microbes work better than one?  What is the most efficient sand size is it only one size or various sizes? This type of research that involves testing thousands of small permutations is perfect for undergraduate researchers and undergraduate classes.

I don’t know what effect all these biological materials will have on construction, but I’m sure it will be fascinating.  Maybe next time someone asks me, “when will we grow cars?” I will tell them, “I’m not sure, but I can grow your garage.”

Thanks for Listing to My Musings
The Teaching Cyborg