They found that sublimation drying, which is typically used for preserving perishable products, could serve as the basis for durable and recyclable Martian structures created with 3D printing. The main components are gelatin and yeast. The results are published in Chem Circularity. The method requires so little energy that it surpasses most existing space construction technologies. And yeast can be grown anew, even if part of it dies. The first people on Mars will immediately have to decide where to live. Building anything on the Red Planet is much more complicated than on Earth. There is almost a vacuum, constant radiation, and temperatures that often drop to −60 °C. The composition of the mixture turned out to be simple: sand and a sticky binder. To reliably bind the small stones, the team combined gelatin with laboratory yeast. When mixed, the microorganisms are coated with sticky proteins similar to those that help mussels cling to underwater rocks. The mixture is then extruded through the nozzle of a 3D printer in an environment with low temperature and reduced pressure. Water instantly freezes and transitions from ice to vapor, resulting in a lightweight porous material resembling foam, yet strong enough. The strength is sufficient to construct a building one or two stories high on Earth, where the gravitational force is three times greater than on Mars. This means that on the Red Planet, it would be easy to erect a multi-story building from such material. This was stated by Zhishen Qiu, an engineer at the Hong Kong University of Science and Technology.
