We write a lot about 3D printing on TreeHugger because the technology is just so promising, but so far most of the objects created are on a small scale and built with plastic. A new machine called the Stone Spray uses natural sand or soil to build solid objects and aims to be the starting point for building much larger infrastructure like buildings or even bridges through 3D printing.
According to Gizmag, the Stone Spray works much like your typical 3D printer in that it uses a computer to follow a 3D design and uses a mechanical arm to build objects by layering material. The device was developed by architects Petr Novikov, Inder Shergill, and Anna Kulik who wanted to bring 3D printing concepts to construction work and with eco-friendly materials.
The device sprays sand or soil that has been mixed with a solidifying agent from a nozzle attached to the arm. Now this is where it has a leg up on regular 3D printers. The Stone Spray doesn't just layer the material upward, it can build in multiple directions, even outwards from vertical surfaces, creating arches and other shapes. After the material has been deposited, it takes several hours for the objects to dry. When finished, they look kind of like coral, but are as solid and strong as concrete.
Right now, the Stone Spray creates objects on a small scale, but the machine proves that this type of digital construction could be done on a larger scale in the near future, illustrated by the image above. Even better, this process utilizes local, natural materials and uses so little energy that it could easily run on solar power.
Below is a video of the Stone Spray building a tower out of sand on the beach.