Researchers at MIT have designed a system that can 3-D print the basic structure of an entire building. It's a strategy toward building that could radically lower the costs of construction. MIT's program is able to print a basic structure in one go.
The system comprises a tracked vehicle mounted with a large robotic arm. At the end of this robotic arm is a smaller, precision-motion robotic arm, used to extrude concrete or spray insulation material. It's free moving, can be customized to print on any suitable surface and is intended to be self-sufficient.
MIT engineers successfully constructed an 11.5-foot high, 50-foot diameter dome in under 14 hours. It included a foam-insulation framework, which was then used used to form a finished concrete structure. It's similar to the building techniques used by traditional builders.
The system can also be modified to re-use locally available resources, such as sand or rock in the construction process itself. Eventually, the aim is to develop a fully autonomous system that can construct houses in remote locations.
Ultimately, the researchers say, this approach could enable the design and construction of new kinds of buildings that would not be feasible with traditional building methods.
MIT is not the first to build a livable structure out of 3-D printing. Chinese construction companies have been using 3-D printing since 2005, and a company called Apis Cor has built a home in 24 hours for $10,000. But unlike "typical 3-D printing systems," MIT says in a press release, "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." That flexibility allows for the MIT system, known as the Digital Construction Platform, to be used in all sorts of environments.
Steven Keating, a mechanical engineering graduate who was lead researcher on the project, says the "construction industry is still mostly doing things the way it has for hundreds of years," using the same materials and built with saws and nails.
"With this process, we can replace one of the key parts of making a building, right now," he says. "It could be integrated into a building site tomorrow."
The goal is a system that is entirely self-sufficient, and can be placed in nearly any environment and start building structures.
The aim 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," said lead author Stephen Keating.