According to a release from Rice University scientists and students in a research group call their mixture “strain paint” and are hopeful it can help detect deformations in structures such as buildings, bridges and airplane wings.
Their study, published online this month in Nano Letters details a composite coating they invented—containing dilute individualized single-walled carbon nanotubes embedded in a polymeric host and applied to form a thin coating (description from the abstract)—that could be read by a handheld infrared spectrometer.
One of the collaborators, Satish Nagarajaiah, a Rice professor of civil and environmental engineering and of mechanical engineering and materials science, says the system could provide an easy method to measure strain in critical applications, such as aircraft. “For an airplane, technicians typically apply conventional strain gauges at specific locations on the wing and subject it to force vibration testing to see how it behaves,” Nagarajaiah says. “They can only do this on the ground and can only measure part of a wing in specific directions and locations where the strain gauges are wired. But with our non-contact technique, they could aim the laser at any point on the wing and get a strain map along any direction.” He also says the paint could be further customized and given additional multifunctional properties for specific applications, noting that the “paint” could also be a corrosion-fighting film or could be made to improve the strength of the underlying material.