The aerospace engineers at US-based Massachusetts Institute of Technology have found a new method of strengthening materials that could make airplane frames lighter and more damage-resistant.

The new technique bonds composite layers that creates a significantly stronger and more damage-resistant material when compared with other advanced composites.

In the new method, the researchers fastened the layers of composite materials together using carbon nanotubes, which are extremely strong atom-thin rolls of carbon.

The researchers implanted tiny ‘forests’ of carbon nanotubes within a glue-like polymer matrix and pressed the matrix between layers of carbon fiber composites.

The nanotubes that look like tiny, vertically aligned stitches worked themselves within the crevices of each composite layer, serving as a scaffold to hold the layers together.

"We are really positive that this will lead to stronger, lighter planes."

In experiments to test the material’s strength, the team led by Spain's IMDEA Materials Institute researcher Roberto Guzman found that stitched composites were 30% stronger than the current composite materials.

Guzman said: “More work needs to be done, but we are really positive that this will lead to stronger, lighter planes.

“That means a lot of fuel saved, which is great for the environment and for our pockets.”

MIT’s aeronautics and astronautics (AeroAstro) professor Brian Wardle said that today’s composite materials feature a very weak and problematic area as they are composed of layers, or plies, of horizontal carbon fibres, held together by a polymer glue.

Wardle said: “A stitch or nail is thousands of times bigger than carbon fibres.

“So when you drive them through the composite, you break thousands of carbon fibres and damage the composite.

“Size matters, because we’re able to put these nanotubes in without disturbing the larger carbon fibres, and that’s what maintains the composite’s strength.

“What helps us enhance strength is that carbon nanotubes have 1,000 times more surface area than carbon fibres, which lets them bond better with the polymer matrix.”

Aerospace groups such as Airbus Group, Boeing, Embraer, Lockheed Martin, Saab, Spirit AeroSystems, Textron Systems are also involved in the research.

Image: MIT aerospace engineers have found a way to bond composite layers, producing a material that is substantially stronger and more resistant to damage than other advanced composites. Photo: courtesy of MIT.