Eco-Friendly Robot Builds Structures from Soil

Building walls and columns without using concrete or waiting for layers to dry. Researchers from ETH Zurich made this possible with a new technique called impact printing. This method uses earth materials like soil, silt, and clay from construction sites. A special robot shoots these materials at high speeds to create strong, durable structures. The best part? It's eco-friendly and faster than 3D printing, which often uses cement, a major source of carbon emissions. The scientists hope to make this technology widely available in the next few years, reducing the construction industry's carbon footprint. Impact printing works by depositing small portions of an earth mixture at high velocities. The robot quickly builds up walls and structures by extruding and shooting the material downward, bonding it strongly without extra adhesives. This earth mixture uses only 1-2 percent of mineral stabilizer compared to the cement in conventional concrete. The process allows for faster construction because it doesn't need pauses for the material to solidify. Plus, it can create complex designs and geometries.3D printing in construction may not be as sustainable. It often uses cement, which contributes significantly to global carbon emissions. Additives in 3D printing mixtures can also make recycling the materials difficult. Impact printing, however, avoids these issues. The team at ETH Zurich has already built walls and columns up to 2 meters tall using this technique. Their next goal is to integrate reinforcement methods for larger and more varied structures. The researchers want impact printing to be used for both off-site prefabrication and on-site construction. They designed the system to work with autonomous construction machines, like their custom excavator called HEAP. The aim is to make the process fully circular, allowing structures to be deconstructed and reused. The project has already won an award, and the team plans to set up a prefabrication facility soon. They believe impact-printed building products could hit the market within three years.