The newest passenger jets are made primarily from advanced composite materials such as carbon fiber reinforced plastic — extremely light, durable materials. But composite materials are also surprisingly vulnerable: the many layers in composites can break apart due to relatively small impacts. MIT aerospace engineers have found a way to bond composite layers in such a way that the resulting material is substantially stronger and more resistant to damage than other advanced composites.
The researchers embedded tiny “forests” of carbon nanotubes within a glue-like polymer matrix, then pressed the matrix between layers of carbon fiber composites. The nanotubes, resembling tiny, vertically aligned stitches, worked themselves within the crevices of each composite layer, serving as a scaffold to hold the layers together. The team found that, compared with existing composite materials, the stitched composites were 30 percent stronger, withstanding greater forces before breaking apart.