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Carbon fiber has been named the “building material of choice” by several industry experts, and is traditionally produced in large, continuous pieces, requiring big machines and facilities to support them. Smaller carbon fiber pieces have been created by 3D printing, but 3D printing, at this point, is highly impractical for large objects like bridges, rockets, and airplane wings. But what if it were possible to 3D print components of a large structure, and then combine them together to create a complete object? MIT’s Neil Gershenfeld and Kenneth Chueng asked this question, sparking the development of a new carbon fiber building system that could, quite possibly, revolutionize the way we build everything.

 When combined together, carbon fiber "cubocts" can create infinite design possibilities. Photo credit: Extreme Tech

When combined together, carbon fiber “cubocts” can create infinite design possibilities. Photo credit: Extreme Tech

MIT’s revolutionary new design combines three fields of research: fiber composites, cellular materials (those made with porous cells), and additive manufacturing (such as 3D printing, in which objects are built by depositing, rather than removing, material). From the smallest objects to the largest structures, here on Earth and potentially in Space, MIT’s new carbon fiber “cubocts” can be combined to create airplanes, rocket fuselages, bridges, levees, and anything else you can think of. The interlocking carbon fiber blocks, reminiscent of the K’Nex or Legos of our childhood, are 10 times stiffer than comparable lightweight materials, creating very strong building materials with a very low density.
MIT's "cubocts" are flat, X-shaped pieces of carbon fiber that can combine to build huge structures. Photo Credit: Phys.org
MIT’s “cubocts” are flat, X-shaped pieces of carbon fiber that can combine to build huge structures. Photo Credit: Phys.org

The bricks are constructed with carbon fiber that has been impregnated with epoxy resin and then formed into the shape of a flat “X”. Each “X” has a hole in the middle, which the leg of another “X” fits into, resulting in an extremely stiff structure of vertex-connected octahedrons, known by the researchers as “cubocts.” The cubocts can be added, removed, or re-oriented to build different structures with different strengths. For example, one structure could be built for resistance to twisting, while another could be geared more towards impact resistance. When tested for strength, the carbon fiber bricks were able to withstand an impressive 12.3 megapascals of pressure, with a very low density of only 7.2 milligrams per cubic centimeter. But the cubocts’ extreme strength isn’t even their greatest advantage.
The legs of each "X" are fitted into the centers of other X's to create any desired shape. Photo Credit: Extreme Tech
The legs of each “X” are fitted into the centers of other X’s to create any desired shape. Photo Credit: Extreme Tech

Where MIT’s new technology really advances past other building materials is in the cubocts’ flexibility. While the individual X’s are very stiff and physically inflexible, they can be readily assembled, disassembled, re-oriented, and replaced if needed, resulting in a building application with limitless possibilities. Weaving different blocks together also allows for the creation of structures that are strong in multiple directions. Ideally, robots will mass-produce the carbon fiber blocks, and then combine them together to build any structure in mind. And eventually, the goal is to build carbon fiber materials that can reassemble themselves on the fly, depending on the given situation and which forces they need to endure.
In a weight test, the cubocts successfully withstood 12.3 megapascals of pressure. Photo Credit: Extreme Tech
In a weight test, the cubocts successfully withstood 12.3 megapascals of pressure. Photo Credit: Extreme Tech

While carbon fiber is considered to be a supreme building material, it can be expensive to manufacture and difficult to repair if damage occurs. MIT’s cubocts achieve the same lightweight strength that carbon fiber is famous for, without requiring the huge machines and facilities, likely reducing manufacturing costs significantly. And since individual components can be easily replaced if damaged, the cubocts provide even more cost savings and design flexibility. Pound for pound, the new technology requires much less material than traditional concrete and steel to carry a given load, reducing construction and assembly costs. Vehicles built with the new cuboct technology would have significantly reduced weight, resulting in lowered fuel use and operating costs.

The applications are infinite. The only question now is: will it work?

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