The other piece to this puzzle is longevity. In order to protect the PLEDs from the elements, the researchers devised a special protective film made from silicon oxynitrite and parylene layers. The material keeps oxygen and water vapor from getting to the electronics, which means it can go on lighting up for more than a day. Right now, the proof of concept needs to be hooked up to electrodes for power, and it isn't doing any sensing. But, in the future, it might be able to harvest power from body heat, or use flexible batteries.