MIT Explores Ways to Strengthen Carbon Fiber

One old stumbling block appears surmountable.

MIT Researchers

MIT Researchers

** Richard Li and Stephen Steiner**

The promise of carbon fiber’s great strength and low weight has never been fully realized, at least when compared with aluminum. But a research project at the Massachusetts Institute of Technology may be on the verge of a breakthrough that could deliver on that potential.

It has long been known that carbon fibers coated with tiny tubes of crystalline carbon called nanotubes could be hundreds of times stronger than steel at one-sixth the weight. But until now, coating carbon fiber with nanotubes has degraded the main carbon fibers, resulting in no net gain in strength advantage.

Brian Wardle, associate professor of aeronautics and astronautics at MIT said, "Up until now, people were basically improving one part of the material but degrading the underlying fiber, and it was a trade-off. You couldn’t get everything you wanted."

A pair of graduate students at MIT working with Wardle, however, have published a paper on how to successfully coat carbon fiber with nanotubes without degrading the underlying fibers. Postdoc candidate Stephen Steiner and graduate student Richard Li authored the paper published in the journal ACE Applied Materials and Interfaces, and lead the team that has been working the problem.

A side benefit of the nanotube coating is that it improves the material’s electrical conductivity – one of the early barriers to incorporating carbon fiber in airframe applications due to concerns over lightning strikes.

Steiner said, "There are a lot of people innovating materials chemistry for advanced aerospace structural applications. I think this is particularly exciting and has a very real possibility to make a large-scale impact on the environment, and on the performance of aerospace vehicles."