Expanding the list of material that can be produced by 3-D printing, researchers at Massachusetts Institute of Technology (MIT) have designed a system to print the basic structure of an entire building.

Structures built with this system could be produced faster and less expensively than traditional construction methods allow, the researchers said. 

"Our system points to a future vision of digital construction that enables new possibilities on our planet and beyond," said Neri Oxman, Associate Professor of Media Arts and Sciences.

Ultimately, the system is intended to be self-sufficient. It is equipped with a scoop that could be used to both prepare the building surface and acquire local materials, such as dirt for a rammed-earth building, for the construction itself. 

The whole system, detailed in a paper published in the journal Science Robotics, could be operated electrically, even powered by solar panels. 

The idea is that such systems could be deployed to remote regions, for example in the developing world, or to areas for disaster relief after a major storm or earthquake, to provide durable shelter rapidly.

The ultimate vision is "in the future, to have something totally autonomous, that you could send to the moon or Mars or Antarctica, and it would just go out and make these buildings for years," Steven Keating, who led the development of the system as his doctoral thesis work, said.

But in the meantime, he said, "we also wanted to show that we could build something tomorrow that could be used right away." 

The system consists of a tracked vehicle that carries a large, industrial robotic arm, which has a smaller, precision-motion robotic arm at its end. 

This highly controllable arm can then be used to direct any construction nozzle, such as those used for pouring concrete or spraying insulation material, as well as additional digital fabrication end effectors.

Unlike typical 3-D printing systems, most of which use some kind of an enclosed, fixed structure to support their nozzles and are limited to building objects that can fit within their overall enclosure, this free-moving system can construct an object of any size, the researchers said. 

As a proof of concept, the researchers used a prototype to build the basic structure of the walls of a 50-foot-diametre, 12-foot-high dome — a project that was completed in less than 14 hours of "printing" time.