D-Shape is a large 3-dimensional printer that uses a binder-jetting, a layer-by-layer printing process to bind sand with inorganic seawater and

magnesium Magnesium is a chemical element; it has Symbol (chemistry), symbol Mg and atomic number 12. It is a shiny gray metal having a low density, low melting point and high chemical reactivity. Like the other alkaline earth metals (group 2 ...

-based binder to create

stone In geology, rock (or stone) is any naturally occurring solid mass or aggregate of minerals or mineraloid matter. It is categorized by the minerals included, its Chemical compound, chemical composition, and the way in which it is formed. Rocks ...

-like objects. Invented by Enrico Dini, founder of Monolite UK Ltd, the first model of the D-Shape printer used

epoxy Epoxy is the family of basic components or Curing (chemistry), cured end products of epoxy Resin, resins. Epoxy resins, also known as polyepoxides, are a class of reactive prepolymers and polymers which contain epoxide groups. The epoxide fun ...

resin—commonly used as an adhesive in the construction of skis, cars, and airplanes, as a binder. Dini

patented A patent is a type of intellectual property that gives its owner the legal right to exclude others from making, using, or selling an invention for a limited period of time in exchange for publishing an enabling disclosure of the invention."A ...

this model in 2006. After experiencing problems with the epoxy, Dini changed the binder to the current magnesium-based one and patented the printer again in September 2008.

Technical description

The D-Shape 3-D printer sits in a 6 m by 6 m

aluminum Aluminium (or aluminum in North American English) is a chemical element; it has chemical symbol, symbol Al and atomic number 13. It has a density lower than that of other common metals, about one-third that of steel. Aluminium has ...

frame. The frame consists of a square base that moves upwards along four vertical beams during the printing process.

Stepper motor A stepper motor, also known as step motor or stepping motor,Clarence W. de Silva. Mechatronics: An Integrated Approach (2005). CRC Press. p. 675. "The terms ''stepper motor'', ''stepping motor'', and ''step motor'' are synonymous and are often u ...

s on each beam control this movement, allowing precise positioning and holding at specific heights. A printer head, spanning the full 6-meter horizontal length of the base, contains 300 nozzles spaced 20 millimeters apart. An aluminum beam runs perpendicular to the printer head, connecting it to the base.

Process

Before printing, a 3-D model of the object to be printed must be created using CAD, a software that allows a designer to create 3-D models on a computer. Once the model is finished, the CAD file is sent to the printer head. The printing process begins when a layer of sand, 5 to 10 mm thick, mixed with solid

magnesium oxide Magnesium oxide (MgO), or magnesia, is a white hygroscopic solid mineral that occurs naturally as periclase and is a source of magnesium (see also oxide). It has an empirical formula of MgO and consists of a lattice of Mg2+ ions and O2− ions ...

(MgO), is evenly distributed by the printer head in the area enclosed by the frame. 3-D printing software slices the 3-D model into 2-D layers for printing. Then, starting with the bottom slice, the head moves across the base and deposits an inorganic binding liquid made up of a solution that includes magnesium chloride, at a resolution of . The binder and sand chemically react to form a sandstone material. It takes about 24 hours for the material to completely solidify. The material resembles, by composition, Sorel cement. An electric piston moves the printer head perpendicular to the motion to fill gaps and ensure uniform binder application. D-Shape completes each layer with four forward and backward strokes. Stepper motors on the vertical beams adjust the base upwards after a layer is completed. The hollow framework above the printer head is refilled cyclically, distributing new sand into the frame to form the next layer. During the printing process, excess sand supports the solidifying material and can be reused for subsequent printings. The process continues uninterrupted until the desired structure is fully printed. After the printer is done with this process, the final structure must be extruded from the sand. Workers use shovels to remove the excess sand and reveal the final product. The magnesium oxide in the sand chemically reacts with the binder, forming a microcrystalline mineral-like material. Compared to concrete, which has low resistance to tension and, as a result, needs iron reinforcement, D-Shape's structures have relatively high tension resistance and do not need iron reinforcement. The building process is reported to take a quarter of the time and a third to a half of the cost of building the same structure with traditional means using

Portland cement Portland cement is the most common type of cement in general use around the world as a basic ingredient of concrete, mortar (masonry), mortar, stucco, and non-specialty grout. It was developed from other types of hydraulic lime in England in th ...

, the material currently used in building construction.

Awards and achievements

NYC Waterfront Construction Competition

In the fall of 2012, D-Shape entered into the NYC Waterfront Construction Competition hosted by the New York City Economic Development Corporation (NYCEDC) in which competitors had to create a solution to help strengthen New York City's deteriorating piers and coastline structures. D-Shape's idea called, "Digital Concrete," was to take 3-D scans of each piece of pier or infrastructure and then print a support jacket for each specific piece. D-Shape won first place and received $50,000 for the idea, and estimated that it could save New York City up to $2.9 billion.

Radiolaria

In 2009, D-Shape printed a large 3-D sculpture, Radiolaria. The sculpture was created by Italian architect Andrea Morgante and inspired by radiolarians, unicellular organisms with intricate mineral skeletons. The original version of the sculpture was a 3 x 3 x 3 m scale model of the full-size Radiolaria that was planned to be put in a roundabout in Pontedera, Italy.

Recent Developments

Currently, Jake Wake-Walker and Marc Webb are working on a documentary titled ''The Man Who Prints Houses'', about Enrico Dini and his invention. D-Shape is still in development. It has printed a

trullo A trullo (plural, trulli) is a Vernacular architecture, traditional Apulian dry stone hut with a conical roof. Their style of construction is specific to the Itria Valley, in the Murge area of the Italian region of Apulia. Trulli were generally ...

, but the printer is unable to print larger structures.

Lunar bases

Because of D-Shape's capabilities, the

European Space Agency The European Space Agency (ESA) is a 23-member International organization, international organization devoted to space exploration. With its headquarters in Paris and a staff of around 2,547 people globally as of 2023, ESA was founded in 1975 ...

(ESA) has taken interest in using the printer to build Moon bases using lunar regolith. D-Shape has been successful in printing components for the lunar bases with a simulated regolith and has tested to see how the printer will work in the environment on the Moon.

References

{{Reflist

External links

* Discovery Channel Covering D-Shape https://www.youtube.com/watch?v=RYaRUVTwIV

2006 introductions Construction Building technology