Scientists in Hong Kong have developed a method to construct Martian shelters using bioengineered yeast and gelatin mixed with dirt, potentially eliminating the need for energy-intensive heating processes. A paper published Thursday by researchers from The Hong Kong University of Science and Technology and The Hong Kong Polytechnic University describes a 3D-printing technique that turns regolith into building material through freeze-drying rather than heat. The approach could dramatically reduce the energy and heavy machinery required for construction on the red planet.
The process combines yeast engineered to produce adhesive proteins with artificial gelatin hydrosol that acts as a growth medium, then mixes in Martian dirt before extruding the blend through a 3D-printing nozzle. When exposed to Mars's cold, dry atmosphere, the mixture forms a foamy substance that freeze-dries as ice turns to vapor, leaving behind a lightweight, porous material. The hardened result achieved compressive and flexural strengths of roughly 12 and 6 MPa respectively, comparable to low-grade concrete found on Earth. The energy required is one to two orders of magnitude lower than heat-processing Martian or lunar dirt into building blocks, and the material can be broken down and reused if at least one yeast cell survives the process.
Senior author Jishen Qiu, an associate professor at The Hong Kong University of Science and Technology, told the paper's publisher that his inspiration came from freeze-dried fruits that become harder. The team tested tiny beehive-shaped structures measuring just 45 mm tall in simulated Martian conditions. "Is there any physical law or fundamental mechanism that prevents us from doing this?" Qiu asks. "I can't see any at this point in time." The researchers say they're confident the technology can scale, though testing pressure retention and gas tightness fell outside the research scope.
The report notes that a functional lunar or Martian habitat must integrate pressure retention, gas tightness, mechanical support, thermal regulation, radiation shielding, dust protection, repairability, and resource recycling. These demands will likely require hybrid architectures that combine the yeast foam with more traditional structures, the authors write. Still, sidestepping the need to heat Martian dirt could cut the energy and heavy equipment necessary to build shelters there, which becomes critical if humans ever actually reach Mars. The biological approach offers a glimpse of how extraterrestrial construction might draw on living systems rather than brute-force industrial methods, though the gap between laboratory demonstrations and survival-ready habitats remains vast.