My skeptic senses are tingling a bit here… Perhaps unfairly; let’s see.
Energy harvesting is a big deal these days, with folks off trying to scavenge enough power to do useful things without the need for an external connection or a battery. Is it possible to take an old party trick and rebrand it as energy harvesting?
Disney has been getting a fair bit of attention over their “paper energy harvester.” Here’s the deal: paper and Teflon are rubbed together, creating a field via the triboelectric effect. The Teflon takes electrons from the paper, setting up an electret. It’s high voltage, low power: around 1000 V open circuit, 40-50 mW through 1 MΩ.
Let’s switch around the language and materials a bit and see if looks at all familiar. Tribozeau the Clown comes to a kids’ birthday party with balloons aplenty. He dazzles them by taking a balloon and rubbing it on his baggy pants. He holds it near a child’s hair; the hair sticks out, yearning for contact with the balloon. He then sticks the balloon to the wall, where it dutifully remains in defiance of gravity. He explains this (as if anyone is listening) as “static electricity.”
Once I watched the demos of the paper harvester, I couldn’t help feeling like all we’re seeing there is good old-fashioned static electricity (which is what the hoi polloi would call it; “triboelectricity” seems so much more elegant).
Depending on the mechanical configuration, you can tap, rotate, rub, or slide the surface with your fingers to generate the effect. The difference from the party trick appears to be that they’ve harnessed it to do something: activate e-paper, blink some lights, whatever might be possible with the given power budget.
It’s a real-time thing only; no energy is being stored. Use it or lose it. My sense is that it’s interesting for interactive displays; Discovery Museum kind of stuff. I can’t decide if it’s more than a gimmick. Granted, for an entertainment company like Disney, there could be something here. But beyond that?
Perhaps it could serve as an actuator – you know, for, say, a light switch. Just enough to kick on the mains juice. But does it have benefits over alternative approaches? Part of what’s touted is its simplicity – you could build it at home. But again, that’s Science Fair stuff – does it matter commercially?
What do you think? Am I missing something here? Is this more than I’m seeing? And are there significant use opportunities that are whooshing madly over my head?
Click here to see their original paper (as PDF).
