A technique pioneered at Bristol University in England and funded by the Engineering and Physical Sciences Research Council will allow for aircraft built with fiber-reinforced polymer (or FRP), which most commercial planes use, to automatically repair minor wear and tear during flight. It'll also make that damage far more visible for ground crews. It doesn't do away with the need for maintenance, but rather it helps keep planes in the air and make repairs more thorough.
The technique involves injecting the hollow glass fibers in FRP structures with colored resin and hardener. When a break in the fibers occur, the resin bleeds out to fill the gap (pictured above), restoring 80-90% of the structure's original strength — just as cells in your blood work to heal cuts.
The damage being addressed is often too small to see with the naked eye, but small nicks can mean big problems for aircraft traveling hundreds of miles an hour. The colored resin will allow ground crews to be able to easily spot these flaws before they become serious threats.
Fiber-reinforced polymers are used in a variety of other applications where the self-repairing technique could be applied, including wind turbines, cars and even spacecraft.