New Optical Technique to Test Paint and More
Many people probably do not realize it, but paint is a very important material. Beyond its ability to color and personalize objects, it also forms a protective layer, which can prevent metals from rusting. Testing paint jobs to ensure they will provide the necessary and expected protection normally requires damaging the paint, but researchers have developed a new, non-damaging technique, as reported by the Optical Society.
This new method employs terahertz imaging. Terahertz radiation falls in the electromagnetic spectrum between infrared light and microwaves, and is already something many are interested in. By firing terahertz beams at a painted object, the researchers found the reflections of the beams can be used to determine the paint's thickness, and potentially more. Many companies are adding nanoparticles to paints for a number of reasons, and terahertz reflectometry can actually detect them, if they are larger than 25 nm.
Potentially this technique could also be used for diagnosing skin cancer, especially if spectroscopy is added to the system. As terahertz radiation is not ionizing, it should pose no threats to humans, as opposed to X-rays or gamma rays which can damage molecules by causing electrons to go flying.
Source: The Optical Society