Disney Research, in Pittsburgh, is demonstrating a paper generator, powered by vigorous hand-rubbing. That eliminates the need or plugging in. In their video, the Disney Research team shows the paper generator as the power source for interactive picture books and for lighting up LEDs. There’s enough voltage in the circuit to drive displays, control e-ink and even send signals to remote devices and run small motors.
The technology, being demonstrated at the at the ACM Symposium on User Interface Software and Technology (UIST), in St. Andrews, Scotland, is relatively simple. All it takes is some polytetrafluoroethylene, or PTFE — better known to most as Teflon and a material that can act as an electrode.
The researchers used two approaches. In one, they rubbed the Teflon sheet to build up a static charge. They then placed it between two sheets of silver-coated polyester. One of the polyester sheets can flex just a little, so the thickness of the “sandwich” can vary. When they tapped the polyester, it generated a voltage and a small current.
The second method is to simply rub the conductive sheet with the Teflon. That creates voltage, too. The voltages are up to 1,000 volts, but the current is tiny — measured in tenths of a milliamp.
The reason both methods work is that some materials, Teflon being one, carry a kind of permanent static charge, which itself has an electric field. When someone moves a conductive material through an electric field, it produces a current.
Since the electrode can be anything, as long as it conducts electricity, it’s simple to build; using conductive inks you can even print paper generators on an desktop.
Credit: Disney Research
via Disney Research