In the future, it is possible that damaged aircraft could repair themselves automatically, even during flight. The inspiration? Healing processes found in nature.
One method could be as simple as a resin that oozes into cracks on demand. Not only might such a breakthrough lead to safer airplanes, it could also lead to lighter craft that would save fuel, drop costs, and reduce global warming gas emissions. Nowadays, aircraft designs that help cope with damage end up adding weight. And the heavier the plane, the more fuel is consumed.
Planes routinely suffer damage from day-to-day use. Researcher Ian Bond, a materials scientist at the University of Bristol in England, says, “You would be surprised how often trucks drive into aircraft when parked at airports. And then you have tools dropped on planes at maintenance hangers, or hailstones when flying through storms. Very subtle damage, little dings and cracks and bangs that, if left undetected, could grow into something serious. At aircraft hangers, a lot of time is spent trying to find these defects.”
The solution would be hollow fibers loaded with epoxy resin and hardener. Such vessels could be embedded in any part of the structure of the plane, and would “bleed out” when cracked to seal any hole, mimicking scabs over a wound. The epoxy is colored, making it easy for mechanics to spot the repairs and make a permanent fix.
Scientists are also working on systems where the healing agent is not contained in individual fibers, but can actually move around in a network of tubes which is, according to Bond, “just like the circulatory systems found in animals and plants.”
Bond and his colleagues are currently developing a custom-made resin optimized for use in the system. Bond suggested that a working system could be up in the next five years.