The device can optimize treatment of neonatal jaundice, skin diseases, and seasonal affective disorder (SAD) and reduce risk of sunburn and skin cancer.

The miniaturized, battery-free wireless devices accurately monitor exposure to the Sun or to lamps for phototherapy. (John Rogers Group/Northwestern University)


The wearable, battery-free device measures — separately and accurately — UVB and UVA exposure for people at high risk for melanoma; for recreational users, the sensor can help warn of impending sunburn. It can record multiple forms of light exposure during outdoor activities, even in the water. The device is always on, yet never needs to be recharged. It weighs as much as a raindrop, has a diameter smaller than an M&M®, and has the thickness of a credit card. It is waterproof and can be mounted on a hat or glued to sunglasses. Currently, physicians don't know how much blue light a jaundiced newborn is actually absorbing or how much white light a patient with seasonal affective disorder (SAD) gets from a light box. The new device will measure this for the first time and allow physicians to optimize therapy by adjusting the position of the patient or the light source. A communication chip embedded in the sensor reads the voltage across the capacitor and passes the result digitally and wirelessly to the user's smartphone. At the same time, it discharges the capacitor, thereby resetting the device.

The wearable sensor is 12 x 6 mm and can be attached to clothing or accessories. (John Rogers Group/Northwestern University)


Northwestern Medicine and Northwestern University's McCormick School of Engineering, Evanston, IL

The new device monitored therapeutic UV light in blue light phototherapy for newborns with jaundice in the neonatal intensive care unit. (John Rogers Group/Northwestern University)


My Skin Track UV, the UVA version of the platform, is commercially available at apple.com and some US Apple stores (it seamlessly integrates with the Apple HealthKit). This version was co-developed with L’Oreal's Technology Incubator and L’Oreal's skincare brand, La Roche-Posay.


The device has demonstrated the ability to monitor therapeutic UV light for psoriasis and atopic dermatitis, blue light phototherapy for newborns with jaundice, white light exposure for SAD, and Sun exposure as well as providing insights into humidity, pollen, and pollution levels.