Hasta La Ideas

Researchers at ETH Zurich are developing an alternative to 3D printing with concrete. They’ve devised a system called impact printing, where an overhead robot rig fires chunks of a clay mixture straight down at the ground. It fires these chunks in a prearranged pattern, and as each chunk hits another, they bond. In this manner, structures are built up.

Once all of the material is deposited, a robotic arm using a circular trowel can be used to do a final pass, smoothing the surface.

“Unlike concrete 3D printing, the process does not require any pauses during which the material can solidify,” the researcher write. “A mixture of excavated materials, silt, and clay is currently used,” though they add that “very minimal additives are required.”

“Entire houses can be built from clay or excavated earth. The material is cheap, abundant, and sustainable as it does not require cement.”

There is one mystery ingredient, which the researchers don’t disclose; they say 75% of the mixture contains “a common waste product” from industry partner Eberhart AG, a company that makes automation and assembly systems.

Here’s a look at the process: