Diagram of Aircraft Wing
Smart skin starts with carbon nanotubes and their unique ability to change their fluorescence under stress. When attached to a surface, they can be used to monitor stress over time through spectroscopy. (Courtesy of the Satish Nagarajaiah Group/Weisman Research Group)

Thanks to one peculiar characteristic of carbon nanotubes, engineers will be able to measure the accumulated strain in an airplane over the entire surface or down to microscopic levels. They’ll do so by shining a light onto structures coated with a two-layer nanotube film and protective polymer.

Strain in the surface will show up as changes in the wavelengths of near-infrared light emitted from the film and captured by a miniaturized hand-held reader. The results will show engineers and maintenance crews whether structures like aircraft have been deformed by stress-inducing events or regular wear and tear.