Technology now plays a major role in the entertainment and interactions we experience on a daily basis. And that inevitably means the things we are interacting with require a power supply or battery be attached. But Disney Research has managed to replace the need for a power supply in some instances with a paper generator.Disney has been experimenting with electrels–types of material that have special electrical properties and carry a “quasi-permanent electric charge.” A group of researchers working out of Disney Research and Carnegie Mellon University has created paper generators that work by placing a sheet of Teflon (polytetrafluoroethylene or PTFE) in between two conducting layers. Those conductive layers can be something as simple as metallized polyester.That sandwich of sheets is thin and light enough to be attached to a sheet of paper and is capable of producing an electrical charge when paper is rubbed over it. The charge generated is enough to light up an array of LEDs, trigger wireless communication with another device like a PC, or sound a buzzer, for example.The video below shows a few examples of how these paper generators can be used:The generators can respond to rubbing, tapping, or a number of gestures. Obvious uses include interactive posters and children’s books, but any sheet of paper can easily be modified to carry some form of battery-free interaction–you can even print parts of the generator using conductive ink. And because they are created from such simple materials, they are very cheap to produce.As this is Disney, there’s every chance the company will incorporate these paper generators into the posters and books they sell. But as they are so simple to create, I don’t see why their use won’t spread to lots of different types of books and even paper kits that let kids experiment with making their own interactive sheets.