Solar powered, wearable device to measure exposure to UV Light

Scientists at McCormick School of Engineering, and Northwestern Medicine have developed a tiny, wearable, solar powered device that enables scientists to monitor therapeutic UV light in clinical phototherapy booths for psoriasis and atopic dermatitis, and blue light phototherapy for newborns with jaundice in the special care baby unit. The device is also capable of monitoring UVB and UVA exposure, individually and precisely, for people at high risk of melanoma. It works when light passes through a window in the sensor and strikes a millimetre-scale semiconductor photodetector. It then produces a minute electrical current with a magnitude proportional to the intensity of the light, which passes to a capacitor where the associated charge is captured and stored. A communication chip embedded in the sensor reads the voltage and sends the result to the user’s smartphone. It discharges the capacitor simultaneously and thus resets the device.
Co-senior author, Dr. Steve Xu, instructor in dermatology at Feinberg and a Northwestern Medicine dermatologist, said: “We hope people with information about their UV exposure will develop healthier habits when out in the sun. UV light is ubiquitous and carcinogenic. Skin cancer is the most common type of cancer worldwide. Right now, people don’t know how much UV light they are actually getting. This device helps you maintain an awareness and for skin cancer survivors, could also keep their dermatologists informed.”