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The technique could revolutionise the assembly of aircraft wings
Researchers have developed a system of tiny, identical and interlocking parts that clip together to create a composite material. Structures created by the technique are tenfold stiffer than existing ultralight materials of the same weight
The technique could revolutionise the assembly of aircraft wings and fuselages, rockets or bridges, said the researchers from the Massachusetts Institute of Technology Centre for Bits and Atoms. Neil Gershenfeld, director of the centre, said the structure is similar to chainmail.
The parts have a special geometry devised by Gershenfeld with colleague Kenneth Cheung. The pieces are flat, cross-shaped composites that clip into a cubic lattice of octahedral cells to form a structure called a ‘cuboct’, which is similar to the crystal structure of the mineral perovskite.
The system is useful for “anything you need to move, or put in the air or space,” said Cheung.
Forces are conveyed through the structures inside each of the tiny pieces and distributed across the entire lattice. The new technique allows less material to carry a specific load than with conventional methods, which could reduce the weight and fuel consumption of vehicles, for example. The structure can be disassembled and reassembled easily to repair damage, or to recycle parts into a different configuration, and the parts can be mass-produced.
Manufacturers make conventional composites as one continuous unit. Large structures such as aircraft wings require big factories where the fibres and resins can be assembled and cured. Joints between large composite components can be liable to cracking and structural failures.
But the new technique sees many small composite fibre loops linked together. This allows the structure to behave like an elastic solid, with a stiffness equal to that of much heavier structures. Gershenfeld and Cheung have shown that by combining different types of part together, they can create structures that morph. These can bend in different ways in response to loads. Instead of moving only at fixed joints, for example, the wing of an aircraft or arm of a robot could change shape.
Gershenfeld and Cheung’s approach combines the fields of fibre composites, cellular materials and additive manufacturing.