What is special about this technology used is that it doesn't require any power nor radioactive part at all. The UV is collected using an LED, then the energy gets stored in the capacitor. To communicate with your phone to track the UV exposure, it uses NFC (near-field communication) technology., which only requires one side (which in this case is your cell phone) to be powered to communicate, instead of using Bluetooth or WiFi. This is why the sensor can be so small as well!
- Answered by Haruna P from San Francisco
- Flag as inappropriate Answer (How it the sensor run if it doesn't need charging? Does it have a radioactive part?)