It is important to understand when to get out from the sunlight – or at least, when to apply sunscreen as any dermatologist will tell you. Consequently, nowadays there are numerous ultraviolet exposure-monitoring devices that would reveal the shade. Not everybody really wants to purchase one, nevertheless, and some of those single-use models that include ecologically dangerous materials. With that in mind, researchers have developed cheap, disposable eco-friendly sensors that are made of paper.
Through an inkjet printer, non-toxic titanium dioxide and a food dye are equally put on a paper substrate. While exposed to ultraviolet lighting for long enough, the titanium dioxide acts as a photocatalyst, creating color to alter and degrade the coloring. That color-change which can easily be detected by the unaided eye, allows customers realize that they truly are at risk of getting sunburned.
Furthermore, by making use of materials to the paper that act as UV neutral density filters, it is possible to find out just how much sunlight coverage is needed to trigger the colour-change to occur. For customers’ various skin shades, as well as their utilization of various SPF levels of sunscreen, developers of the sensors may account in this manner.
The study was conducted at Australia’s University of New South Wales, and it is explained in a document which was recently printed within the journal ACS Sensors.