Disney Research, Pittsburgh and Carnegie Mellon University have released details of another one of their collaborative projects, this one involving thin, flexible generators that can be built into paper items such as the pages of a book. By simply rubbing or tapping one of these pages, users can illuminate LEDs, prompt applications on linked computers, or even activate e-ink displays – no batteries or outlets required.
In the demonstrator prototypes, one labeled section of a page contains the Paper Generator. The generator itself consists of a thin sheet of polytetrafluoroethylene (or PTFE, better-known to you and I as Teflon) that is sandwiched between two sheets of conductive material such as silver-coated polyester. These act as electrodes.
Those sheets have a paper backing that forms part of the page. They can also be made from paper with conductive ink printed on their facing surfaces.
Thin strips of adhesive foam join the two electrode sheets together face-to-face, while maintaining a small gap between them in which the PTFE sheet is located. That foam also allows all three sheets to wiggle around a bit relative to one another, while still holding them all in place.
When the user rubs the paper face of the top sheet, it creates an electrical charge that is stored on the PTFE. The rubbing motion also causes the electrode sheets to move relative to one another against the PTFE, which results in an alternating electrical current being generated.
Wires embedded in the page then carry that low-amp, high-voltage electricity to power one or more LEDs, an e-ink display, a tiny motor, a buzzer, or something else built into the page. The current can also be used to power an infrared transmitter, which causes actions to take place on a wirelessly-linked computer.
Along with books, the Paper Generators could conceivably find their way into any number of other applications, such as interactive posters. More information is available in the following video, and in the research paper that can be freely accessed via the link below.
Source: Disney Research