2.0. This strange biomaterial could be used to build the homes on Mars

Creating a closed-loop, zero-waste artificial system using minimum energy and equipment — with Chitin.

Although none of us have ever been to Mars, we know it’s a dead place. Space aficionados who dream of colonizing the red planet will eventually need to face the scarcity of basic resources on the Martian surface. We already face this issue on Earth, where our rate of consumption has reached a point to where we would need an extra 0.6 of another Earth to continue to sustain ourselves. So moving into an environment where there’s nothing is going to be challenging for humans.

Current construction material isn’t feasible

NASA has hopes to get people on Mars by the end of 2030, but the path of how we plan to transport material from planet to planet is incredibly tricky.

Concrete, for instance, requires a substantial amount of added water in order for it to be usable. But the only form of water available at Mars is at the poles, which isn’t enough to make concrete upon concrete buildings. Considering we need to build entire Martian villages, this plan certainly isn’t feasible and to even transfer any form of building material (wood, steel, stone, sand, etc.) to Mars is a challenge, as it costs around $10,000 to transport a singular pound of material out of Earth.

In order for us to actually set up a habitable base on Mars, we need to consider integrating Mars’s regolith (loose rocky material covering the surface) into the technological manufacturing process. But at the same time we would also need to find a way to cut the cost of the bill as current manufacturing methods require specialized equipment and a substantial amount of energy.

Turning to Martian soil

At Singapore University of Technology and Design, Javier Fernandez and his colleagues may have found the perfect material — chitin. This is an organic polymer present in the exoskeletons of insects and crustaceans and is the primary component of fish scales and fungal cell walls. Because it’s so abundant in nature and can form durable substances through natural processes, people have realized it can be transformed into viable building material for Martian habitats and tools.

“Nature presents successful strategies of life adapting to harsh environments. In biological organisms, rigid structures are formed by integrating inorganic filler proceed from the environment at a low energy cost (e.g., calcium carbonate) and incorporated into an organic matrix (e.g., chitin) produced at a relatively high metabolic cost.” — Fernandez

Obtainable on The Red Planet

Fernandez’s team experimented with the potential of this material by extracting a form of chitin from a shrimp’s exoskeleton and treating it with sodium hydroxide. In fact, sodium hydroxide is easily attainable on Mars through a process called electrolytic hydrolysis: the process of using electricity to decompose water into oxygen and hydrogen gas (if you’ve read The Martian by Andy Weir, this is how the protagonist creates his oxygen while stranded on Mars).

The chitin was then dissolved in a low concentration of acetic acid, and the chitin solution was combined with a sand-like material, similar to the loose substance found on Mars’s land. A thick sediment was formed, and the last ingredient was water; however, compared to concrete, it required very minimal amounts, so the quantity readily available in Mars’s subsurface ice is an ample amount.

Building a model with a 3D-printed lander module illustrates a possible scenario of fabricating habitats on Mars. Retrieved from arsTECHNICA.

From here the chitin material was molded with various casting techniques, producing cartoon figures and tools like functional wrenches which they tested by tightening a hexagonal bolt. It was acknowledged that this wouldn’t be durable enough to replace metallic tools for specific critical space application, but it proved to be a material strong enough to build rigid protective structures around inflatable habitats.

Reaching zero-waste

Chitin was originally devoted to creating circular ecosystems (where manufacturers design products to be reusable) in urban environments, considering we are facing a shortage of materials here on Earth. But due to its high efficiency, it creates a scalable minumum energy and equipment method to produce zero-waste material in closed artificial ecosystems on lifeless planets as well.

All life waste material would decompose into Mars’s regolith, which would be collected and combined with sodium hydroxide, acetic acid and water to form a workable sediment. This then would be molded using various casting techniques. The structures and tools built with the chitin material can decompose back into the regolith when it is no longer necessary or is in poor condition, again creating the basis of material for new products. Retrieved from arsTECHNICA.

“Bioinspired manufacturing is not a substituting technology for synthetic polymers, but an enabling technology defining a new paradigm in manufacturing, and allowing to do things that are unachievable by the synthetic counterparts. We have demonstrated that they are key not only for our sustainability on Earth but also for one of the next biggest achievements of humanity: our transformation into an interplanetary species.” — Fernandez

• Ashley