According to the American Cancer Society approximately 5.4 million basal and squamous cell skin cancer cases arise each year. Yet, exposure to sunlight does contribute to the production of Vitamin D, which is necessary for bone health and even bone cancer prevention. So how does one know how much sun exposure is enough? Scientists at USC Viterbi School of Engineering have developed a color-changing wearable that can notify users of their total exposure, allowing them to achieve a balance.
It's a patch, much like a Band-aid and very easy to wear. It also requires no power, it doesn't run out of "juice" or need to be re-charged. The sensors have been created by the Armani Lab and can still function when wet and can even adjust their responses when sunscreen is applied. Furthermore, the sensors can be stored for a period of up to five weeks. These sensors are made of material patented by Armani and Lee and were constructed of FDA-approved non-toxic polymers for human use and food contact. Their innovation is documented in "Flexible UV Exposure Sensor Based on UV Responsive Polymer," in the journal ACS Sensors.