Researchers at Northwestern University have developed a “virtually indestructible” solar-powered UV sensor. Described as the world’s smallest wearable, the battery-free device is thinner than a credit card and smaller than an M&M candy, but can warn people about UV over-exposure and help clinicians to optimize dosing during light therapy.
Not knowing of Northwestern’s role in this technology, we recently covered the now available sensor when it was released as a L’Oreal product through Apple stores.
Light therapy has numerous applications, including blue light therapy for jaundiced newborns and UV therapy for people with psoriasis. However, accurately measuring the dose of light has been tricky, highlighting the need for accurate sensors. “We know that the lamps for phototherapy are not uniform in their output – a sensor like this can help target problem areas of the skin that aren’t getting better,” said Steve Xu, a researcher involved in the study.
Moreover, measuring UV skin exposure is important to help mitigate the risk of skin cancer. “We hope people with information about their UV exposure will develop healthier habits when out in the sun,” said Xu. “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.”
A small window in the sensor allows light to enter, where it strikes a tiny photodetector. A communication chip in the device transmits the light data to the user’s smartphone, and also allows the sensor to access weather and UV index information, which it combines with the light data to calculate when a user has had enough sun. A smartphone alert then informs the user that they may need to get into some shade.
The sensor is battery-free, water-proof, and solar powered. As it is “always on,” the sensor can perform more accurate measurements than currently available dosimeters, which sample light intensity periodically. It is also significantly lighter and less expensive.
“From the standpoint of the user, it couldn’t be easier to use – it’s always on yet never needs to be recharged,” said John Rogers, another researcher of the study. “It weighs as much as a raindrop, has a diameter smaller than that of an M&M and the thickness of a credit card. You can mount it on your hat or glue it to your sunglasses or watch.”
Here’s a promo video for the La Roche-Posay My Skin Track UV:
Through a collaboration with L’Oreal, a version of the device is already available commercially…
Study in Science Translational Medicine: Wireless, battery-free, flexible, miniaturized dosimeters monitor exposure to solar radiation and to light for phototherapy…