Paper Keyboard Is Self-Powered

Building a keyboard isn’t a big project these days. Controller chips and boards are readily available, switches are easy to find, and a 3D printer can do a lot of what used to be the hard parts. But engineers at Purdue have printed a self-powered Bluetooth keyboard on an ordinary sheet of paper. You can see videos of the keyboards at work below.

The keyboards work by coating paper with a highly fluorinated coating that repels water, oil, and dust. Special inks print triboelectric circuits so that pressing your finger on a particular part of the paper generates electricity. We were skeptical that the Bluetooth part is self-powered, although maybe it is possible if you have some very low-power electronics or you manage the power generated very carefully.

Conductive nanoparticles are involved and — supposedly — they keyboards cost less than $0.25 to print. We presume that is after the fixed costs of setting everything up.

What would you use this for? It seems like paper isn’t going to be a good choice for long-term durable goods like laptops or cell phones. We can imagine a deli menu with buttons on it, perhaps, but it seems like it will be a while before that’s truly practical.

Still, if it is as robust as it looks, it should be interesting for something. We just aren’t sure what yet. Triboelectricity from key strikes probably isn’t going to run much electronics for very long, but it is fine for energizing some wires for a keypress. This isn’t the first paper generator we’ve seen, oddly enough.

11 thoughts on “Paper Keyboard Is Self-Powered

    1. Um, there actually *are* electronics involved, you don’t get bluetooth from just some printed wires. The claim isn’t that there’s no need for electronics, the claim is that there’s no need for a *battery*.

    1. According to the paper: …the rectified triboelectric voltage peaks generated by a 1 cm^2 triboelectric area … are efficiently regulated by a custom-made synchronized switch harvesting on inductor (SSHI) module. This SSHI module is calibrated so that only triboelectric peaks greater than 4.9V result in the generation of steady 3.3V signals capable of activating a low-power wireless microcontroller equipped with a Bluetooth module.

      There is a figure showing what must be a BLE transaction because it is very short with no association.

    2. The 2nd paragraph of this article mentioned “pressing your finger on a particular part of the paper generates electricity”, which made me initially think of an action similar to piezoelectric properties. Have to do more research on it an mull…

  1. At first blush. I agree this looks like BS. Especially when you look at the volume control video.

    When I read their website on the other hand, I can buy 50% into the idea. The paper is just the medium that they are printing a new type of circuit-medium. They use the phrase “highly fluorinated molecules” which is a fancy way of saying insulator, that appears to be transparent. Then they use conductive inks to create the circuit.

    As to the triboelectric, interesting but I have enough trouble getting recognized by capacitive touch sensors that I do not look forward to this being real.

    The implication of triboelectric power is the keyboard will work for a while, then as you dissipate your charge the keyboard will become unreliable. Forcing you to charge up again to get it to work. I do not fancy having to rub a glass rod in some wool to make a keyboard work. Which makes me wonder if they had a Wimshurst Machine attached to the person in the video.

    Then I found this paragraph…
    “Martinez and his team have worked with the Purdue Research Foundation Office of Technology Commercialization to patent some of his technologies related to robots and other design innovations. ”
    …which makes this announcement a funding/cash grab. So, they can do more research.

    Possibilities are always enticing. Realities are usually a smack in the face.

    So, I am betting this is real but really difficult or given the “highly fluorinated molecules” stupid-expensive.

    1. Well, all publications of preliminary research results are ultimately a bid for more funding; it’s the publish-or-perish paradigm at work. And I was under the impression that it’s a keypress-generated triboelectric effect, and not dependent on whatever static electricity you’re bringing to the paper — though that’d actually be a lot more fun. I want to see the proposed deli menus in a stack next to a sign pointing out the shag carpeting and imploring customers to shuffle their feet a bunch.

      Paper keyboards remind me — anybody else remember the Fly Fusion smart pens? One of the “educational” toys from Leapfrog, it depended on special paper and a camera in the pen to track pen position, so you could cover a page in the notebook with writing or scribbles, and then upload the ink to your computer — but the salient bit is that with certain cartridge programs, you could draw glyphs and activate them, so you could, say, draw a calculator keypad in your notebook and then tap out your calculations. The only output was audio and a couple of LEDs. I picked up one when they were being remaindered and still have it someplace.

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