Carbon Nanotubes in Advanced Composites Enable Detection of Aircraft Defects

I have made light of some efforts to use carbon nanotubes in the filler materials for carbon fiber composites. It always struck me as more a marketing ploy than an effort to produce a carbon composite that was significantly stronger than typical varieties.

But researchers at MIT may have devised an additional way to have it make sense to include carbon nanotubes in these composites by developing a simple, hand-held device capable of detecting internal damage to composites…just as long as the composite contains carbon nanotubes.

Brian L. Wardle, associate professor of aeronautics and astronautics at MIT, along with his colleagues have developed a solution that requires only a small current be applied to the material of the aircraft that quickly heats up the carbon nanotubes and allows the use of thermographic camera for detecting flaws without the cumbersome need for heating the entire surface of the aircraft.

"It's a very clever way to utilize the properties of carbon nanotubes to deliver that thermal energy, from the inside out," says Douglas Adams, associate professor of mechanical engineering at Purdue University, in an MIT press release.

The research, which was initially published in the March 22^nd online edition of the UK’s Institute of Physics journal Nanotechnology, depends on carbon nanotubes being included in the material matrix in order for it to work.

This could be a way in which carbon nanotubes will become more widely used in these advanced composites. It allows for a much cheaper inspection method than is currently available, which alone could offset the extra costs of use CNTs in the fillers for these materials.

It certainly should benefit one of the main aims of Wardle’s work, which is “to improve the performance of advanced aerospace materials/structures through strategic use of carbon nanotubes (CNTs).” 

While the US Air Force and Navy are reportedly interested in the technology, it will be interesting to see if commercial aircraft become involved. It seems now CNTs are no longer only selling their strength in composites but their ability to cheapen inspection.