Researchers at ETH Zurich have introduced a new robotic 3D printing method for cement-free low-carbon materials for a circular economy. 

Using a technique called 'impact printing,' the team demonstrated a mixture of excavated materials, silt, and clay that was less dependent on additives for its structural strength due to the high-velocity deposition process. Their aim was to "increase the cost competitiveness of sustainable building materials through efficient and automated production."

First, a custom printing tool was developed that can be integrated on multiple high-payload robotic platforms. The tool was then integrated with a high-payload Gantry system within the ETH's Robotic Fabrication Laboratory. The hardware is also compatible with an autonomous legged excavator system called HEAP, also developed by the Robotic Systems Lab. It has shown capabilities to build structures as tall as up to 10 feet high and works at a pace equal to roughly 32 feet per second.

The ETH says that in the future this will enable "the construction process to be deployed directly in unstructured sites with variable terrain to realize wall structures and infrastructure such as acoustic barriers."

The robotic process enables the production of freestanding and highly customizable wall and column structures. Novel software and computational design methods were developed to design these structures and control the robotic construction process. It joins a host of other research projects into 3D printing undertaken by the ETH recently, including last year's development of recycled foam insulation materials and the new 'Fluid Forms' sculpture from the Digital Building Technologies group.

The process won the 3D Pioneers Challenge in 2023 in the Architecture  category. The ETH is now planning to leverage the ETH Spin-off to commercialize its latest breakthrough. Similar developments in automation have combined with labor shortages to propel the market for robotics construction north of $383 million in 2024 in the U.S. alone, according to Mordor Intellegence.