Courtesy Bruce WeismanScientists at Rice University developed a new type of paint, infused with carbon nanotubes, that can detect strain in bridges, buildings, and airplanes before the signs of deformation become visible to the naked eye.
This is how it works: The paint is applied to the desired structure and allowed to dry. A laser beam is then focused on the structure, which excites the carbon nanotubes, and in turn, causes them to fluoresce in a way that indicates strain. Finally, a handheld infrared spectrometer is used to measure this fluorescence.
The advantage of strain paint over conventional strain gauges is that the gauge (the paint, in this case) and the read-out device don't have to be physically connected. Also, strain paint allows you to measure strain anywhere on the structure, and along any direction. This product is not yet on the market, but it will benefit all of us, as I'm sure we all find the structural integrity of our planes, bridges, and buildings to be pretty important.