A team of Australian and Spanish scientists, these belonging to the University of Granada (UGR), has created a bracelet that warns whoever wears it on their wrist of the damage of solar radiation to which they are exposed. The key to its operation lies in a sensor that detects and distinguishes the degree of ultraviolet (UV) radiation . Within the spectrum of UV rays include UVA, which are the least energetic, UVB and UVC, which emit more energy, are much more dangerous and can cause skin cancer .
Four smileys with sad and happy faces appear on the bracelet, depending on the radiation damage to which we are exposed. The device contains an invisible polyoxometalate liquid that turns colored when affected by ultraviolet rays. The ink can be printed on paper and incorporated into disposable wristbands which, by means of emoticons with four face gradations (from happiest to saddest), indicate that 25%, 50%, 75% and 100% have been exceeded, respectively. , UV sun exposure limits considered safe for people.
The article in which this invention is reported has been published in the journal Nature Communications . As explained by its main author, the researcher from the Inorganic Chemistry department of the University of Granada José Manuel Domínguez Vera, to date there were only sensors for UV radiation in the market as a whole , without discriminating A, B or C (UVA, UVB and UVC).
“ UVB and UVC radiation are retained by the ozone layer . This sensor is especially important in the current context, where the hole in the ozone layer causes us to be exposed to such harmful radiation ”, explains the researcher.
The sensor designed by the authors is based on a photochromic molecule called PMA (which changes color depending on its redox state) and lactic acid. “ We have built different inexpensive devices that allow us to use PMA and lactic as an ink that is absorbed on a conventional paper . This paper turns blue depending on the type of UV radiation and its intensity ”.
In addition, the researchers have adapted the device to simulate different skin types, since the damage from UV radiation depends on the skin type. The work is the result of a collaboration between two members of the UGR research group BIONanoMet (FQM368), Ana González and José Manuel Domínguez-Vera, and the group of Dr. Vipul Bansal (from RMIT University of Melbourne (Australia).
