Disney's Paper Generators

Didn't you just love listening to those singing/talking cards you got for your birthday? Maybe instead you were more inclined to tear the card up and play around with the guts inside. Or maybe you just wanted to take a hammer to those awful melodies after hearing a kid play them for the gazillionth time… Regardless of your approach, researchers at Disney have developed a new paper-like energy harvesting technology which may change the way these fun cards, and many other low-power electronics, power themselves.

Via lifehacker.com

Energy harvesting is a term that defines any means of capturing small amounts of energy to use in wireless devices. Those solar lights on your walkway and that self-winding watch your weird uncle wears are examples of autonomous devices that harvest outside energy (solar and kinetic, respectively) to power themselves. This means no wires, no charger, and no battery replacement- nice! As long as sufficient energy can be captured, the device will run forever (or rather, until the device itself fails). This is a luxury I wish my dress watch had, but alas, the battery is dead and I am too lazy to replace it…woe is me.

But back to Disney's work: they've developed a means to utilize rubbing, tapping, and other simple hand/finger motions to transfer kinetic energy to power small devices like LEDs for a short time. Their approach uses electrets, which are dielectric materials which like act like magnets, holding a quasi-permanent electric charge ("electret" ~= electric magnet). Electrets already have uses in microphones, copy machines, and air filters which collect particles electrostatically. Disney's application aims to make printed materials (books, posters, etc.) interactive via electrets-powered "Paper Generators," removing the need for a battery.

Tap the button to light up the LEDs - Via phys.org

The approach involves taking the electret material, in this case a thin and flexible layer of polytetrafluoroethylene (PTFE, aka Teflon), and placing it in between two conductive layers that serve as electrodes. The PTFE builds up charge as paper is rubbed against it, and the outer layers then create a tiny alternating current when moving relative to each other against the PTFE. By arranging the layers in different ways, these paper generators can be designed to capture energy from different movements (tapping, touching, rubbing, or sliding). The current produced by these devices is very small, measured in hundreds of microamperes, but the voltage (up to 1000 volts) is ideal for the small application e-paper displays.

Disney's vision is to use this technology to bring books and other printed materials to life via LED arrays, e-ink displays, small speakers, and more. The possibilities seem as limitless as the imagination, which fits the Disney company very well. And it's not going to cost a pretty penny either, since these devices are very simple. "There's nothing here that I can't build by hand in five minutes," says Mustafa Emre Karagozler, one of the team's researchers. Paper Generators can even be printed using conventional ink-jet printers equipped with conductive ink cartridges.

It's not a save-the-world breakthrough by any means, but Disney's new development may open the door for a new realm of simple interactive posters, books, and cards. Perhaps years from now I'll be buying a new sort of musical card for my niece or nephew.

Via craftjuice.com

Source: Phys.org