Making Big Things Out of Small, 3D Printed Pieces

(MIT News) MIT researchers have developed a lightweight structure whose tiny blocks can be snapped together much like the bricks of a child’s construction toy. The new material, the researchers say, could revolutionize the assembly of airplanes, spacecraft, and even larger structures, such as dikes and levees. The new design combines three fields of research, fiber composites, cellular materials (those made with porous cells) and additive manufacturing (such as 3D printing, where structures are built by depositing rather than removing material).

The concept arose in response to the question, “Can you 3D print an airplane?” While the researchers realized that 3D printing was an impractical approach at such a large scale, they wondered if it might be possible instead to use the discrete “digital” materials that they were studying. The new approach to construction is described in a paper appearing this week in the journal Science, co-authored by postdoc Kenneth Cheung and Neil Gershenfeld, director of MIT’s Center for Bits and Atoms.

Gershenfeld likens the structure — which is made from tiny, identical, interlocking parts — to chainmail. The parts, based on a novel geometry that Cheung developed with Gershenfeld, form a structure that is 10 times stiffer for a given weight than existing ultralight materials. But this new structure can also be disassembled and reassembled easily — such as to repair damage, or to recycle the parts into a different configuration.

The individual parts can be mass-produced; Gershenfeld and Cheung are developing a robotic system to assemble them into wings, airplane fuselages, bridges or rockets — among many other possibilities.