Self-Healing Hulls

In the 2008 November issue of IEEE Spectrum, there is an article that talks about self-healing hulls. The carbon-fiber composition of a yacht can considerably heal itself after a collision. You can improve the healing process by inducing a little electric current. The work is being done by Eva Kirkby, a graduate student from EPFL. The main idea is that carbon-fiber is composed of carbon fibers and epoxy; the problem is that in case of impacts, these materials tend to separate internally causing cracks parallel to the surface of the material. In order to counter this problem, the material is infused with hundreds of very small bubbles filled with liquid-monomer molecules plus some small particles of catalyst. The outcome would be a hardening of the material. In order to keep the concentration and size of the bubbles to a minimum, Kirkby incorporated into the composition wires of a smart alloy, an alloy that can return to its initial shape after being deformed by applying heat (electricity) through it. Great idea!