UV sensor based on polyurethane foam

Abstract

Ultraviolet light (UV) present in solar radiation has an important effect on the health of human skin. For that reason, we developed a disposable and easy-to-manufacture UV light sensor based on surface color change of a polyurethane (PU) film and examined its performance against radiation received from a lamp or from the sun. The chemical modification after UV exposition and the consequent color variation from light yellow to brown in PU sensor were studied by using RGB image analysis and a reflectance prototype containing an Arduino board. It was found that the photochemical modification of PU films increases absorption of visible radiation in the blue spectrum range. Furthermore, PU surface was more sensitive to UV (<390) than that found in visible light when exposed to sunlight, which was associated with the presence of a chromophore in the material modified. In addition, it was found that the extract obtained from irradiated PU showed its maximum absorption at 309 nm. Hence, the use of this economical light radiation sensor seems to be a very promising tool to determine exposure to UV light from the solar spectrum.