The world’s smallest wearable, battery-free device has been developed by Northwestern Medicine and Northwestern Engineering scientists to measure exposure to light across multiple wavelengths, from the ultra violet (UV) to visible and even infrared parts of the solar spectrum. It can record up to three separate wavelengths of light at one time.

The device’s underlying physics and extensions of the platform to a broad array of clinical applications are reported in a study published December 5 in Science Translational Medicine. These foundational concepts form the basis of consumer devices launched in November to alert consumers to their UVA exposure, enabling them to take action to protect their skin from sun damage.

When the solar-powered, virtually indestructible device was mounted on human study participants, it recorded multiple forms of light exposure during outdoor activities, even in the water. The device monitored therapeutic UV light in clinical phototherapy booths for psoriasis and atopic dermatitis, as well as blue light phototherapy for newborns with jaundice in the neonatal intensive care unit. It also demonstrated the ability to measure white light exposure for seasonal affective disorder…. Continue reading.