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PrintDisplay: DIY Displays and Touchscreens Anyone Can Print

Posted by samzenpus on from the print-and-watch dept.

Zothecula writes For years now, we've been promised miraculous new flexible touchscreen displays, but the deployment of such technology in big consumer products, like say the LG G Flex, hasn't started any revolutions just yet. That could soon change thanks to a team of computer scientists from Germany's Saarland University who have developed a technique that could allow anyone to literally print their own custom displays, including touchscreens."

14 comments

  1. What's the voltage? by Ungrounded+Lightning · · Score: 2

    "Electroluminescent"? Is this REALLY thin? Or is the voltage substantial, like approaching three digit volts? (Or some third option, like a very low voltage electroluminescent material?)

    (I'd check the referenced paper but can't get the time for that for another 12 hours, so if someone else gets to it, please follow up.)

    Regardless, this looks very promising. Even if it turns out not to be practical, it should put the pressure on manufacturers to get a move on with commercial products at reasonable price points and improved form factors - or lead to the rise of disruptive competitors.

    --
    Bantam Dominique roosters crow a four-note song. Once you've heard it as "Happy BIRTHday" you can't NOT hear it that way
    1. Re:What's the voltage? by Anonymous Coward · · Score: 1

      From the paper: 1.0 mA at 220 Vpp, 230Hz to 390Hz. The display adds 110 m to the substrate.

    2. Re:What's the voltage? by killkillkill · · Score: 2
      Relevant excerpt

      For mobile applications, our prototypical controller uses a small driver IC (Model Durel D356B, sine wave, 220 Vpp, 230Hz to 390Hz). This driver IC generates the high-voltage AC signal from a 1.0-7.0V DC power source. If a higher luminance is required, a stronger 0-12.0V driver IC with a slightly bigger footprint can be used (Model Sparkfun DC12V10M, sine wave, 220Vpp, 800Hz to 3.5KHz). A microcontroller (ATmega2560) triggers optocouplers (MOC3063) for multiplexing the high-voltage signal between display pins.

  2. Electroluminescent display by monkeyxpress · · Score: 3, Informative

    Interesting project, and some of their samples look quite cool. Only issue I see is that it is EL tech, which requires a rather annoying high voltage step up inverter to drive (around 200V). You used to be able to buy EL sheets that you could cut holes and stuff in to create custom displays, which was quite cool, so this is sort of just a variation of that. EL fell out of favour once LED took over as it was harder to drive and not particularly efficient. Anyway looks like it could be quite a cool system for getting people enthused about engineering/electronics if they can make the print system cheap enough.

    1. Re:Electroluminescent display by ColdWetDog · · Score: 1

      This is pretty interesting. From a brief perusal of TFA, it seems like the only thing hard to DIY is the special ink and paper - both of which could be manufactured by any company considering commercializing this (the authors made the stuff). The electronics are pretty simple assuming that you can avoid electrocuting yourself on 220V.

      I would certainly buy a kit even if I have no practical use for it.

      --
      Faster! Faster! Faster would be better!
    2. Re:Electroluminescent display by Rei · · Score: 1

      I wonder how cheap it is. Because, couldn't something like this really be first step towards all of those "everything is a computer screen" techs you always see in sci-fi, like fliers with full motion animation and the like? If a whole display can be laid out with an affordable ink, then the only issues in the way of ubiquity are 1) power, and 2) the input signal. A flexible printable battery could enable #1 (just have it as the first layer of your screen), and/or a printed solar cell. #2 would require either low cost computing hardware... or conversely, perhaps just a simple rf receiver for some protocol which cell phones can transmit and a unique broadcast code for the content to be displayed on the screen. The user's cell could thus function as the computing hardware, downloading the appropriate code to run in a sandbox, like javascript on a website, with the trigger being the user touching the product.

      We've grown accustomed to products having what's written on them be fixed but the potential for what they could display is almost unlimited - if the cost of the display, computing, and basic sensors could be kept low enough. A milk carton letting you know when it's gone bad. A piece of cable warning you that it's corroded on the inside and its resistance has gone outside of design parameters. A cereal box having its product information printed in the language you speak. A simple mechanical wrench that nonetheless tells you how much force you're applying. Etc.

      If the cost of adding that sort of stuff drops far enough below the cost of the product, people will start to add it everywhere (sort of like what happened with LED indicator lights). And yeah, of course just like with LEDs some manufacturers will overdo it and get annoying. But overall it'll still be a good thing. Let's not forget that LED indicators lights can be very useful. I have an old MIG welder from the 1960s or 1970s. I thought it was broken for a couple days until I discovered that the torch just wasn't pushed in far enough and wasn't getting a good connection. There was not a light or any other sort of indicator showing that the thing was even getting power, let alone working - I had to go in with a multimeter and probe one connection after another until I saw that everything was fine except for the trigger connection. A handful of indicator LEDs would have told me that immediately. They could have of course used small incandescent bulbs back then, or other such lighting technology. But we all know those would have burned out long ago and nobody would have bothered to replace them, and they would have cost a lot more more than modern LEDs - so they didn't bother.

      One day, cheap low-cost displays may be as ubiquitous as indicator LEDs have become.

      --
      "Are you hungry? I haven't eaten since later this afternoon." -- Primer
    3. Re:Electroluminescent display by MouseTheLuckyDog · · Score: 1

      Haven't read the original article, but if this is true then the technology is doomed to the buzz of the elecrical driver, which many find to be annoying.

    4. Re:Electroluminescent display by sherr · · Score: 1

      High voltage is only dangerous because it can enable large amounts of current to flow through your body (assuming large amounts of current are available), the current is what actually kills you. The IC that drives the display is only capable of driving 1 mA which is only barely at the threshold of perception and not in any way dangerous. http://www.allaboutcircuits.co...

    5. Re:Electroluminescent display by Aighearach · · Score: 0

      No, "it is the current that kills you" is only true for static electricity.

      For circuits, you can't separate the voltage and the current in that way, and the current isn't the variable. You have voltage, resistance, and current. The current is determined by the voltage and the resistance. In an electrocution setting, the resistance is fixed; whatever the resistance of your skin is doesn't change based on what you touch. However much current your body can draw, it will, based on... the voltage. Because the resistance isn't a variable that has to do with the current source you accidentally connect yourself to, the voltage is what tells you how much current will be drawn.

      The only exceptions are where the risk is from inductors, which will try to maintain the current. But that doesn't apply here.

      To learn more about this dangerous idiocy, see: https://www.youtube.com/watch?... "While there is some truth to it, it is basically a load of crap, and dangerously misleading." Status: busted

    6. Re:Electroluminescent display by Anonymous Coward · · Score: 0

      In an electrocution setting, the resistance is fixed; whatever the resistance of your skin is doesn't change based on what you touch

      This is the part that is false and why some high voltage systems can be a lot less hazardous than they their voltage would naively imply. It is not just the resistance of the person, but the output impedance of the voltage source. A lot of low power, high voltage sources have a rather high output impedance and can never directly exceed some current. I have hipot and diode testing equipment that can generate thousands of volts, but are limited in current to microamps considering they are used to test things even more sensitive to damage than the human body. You can touch the terminals and not feel anything. Unless you hook the output up to a capacitor (one much bigger than the self-capacitance of a human body) and wait a long time for it to charge, you won't get a lot of current out.

      Also, for very short discharges, there is shift from danger from current levels to danger from certain energy of discharge. A fast static discharge from a human body can reach 5 A for a very small fraction of a second, but the total energy involved is small. Things like the nerves in the heart react on timescales on order of milliseconds, and many discharges can be much faster than that and require substantially more current to have a biological impact.

  3. 220V by monkeyxpress · · Score: 1

    From the paper.

    1. Re:220V by ihtoit · · Score: 1

      all my EL gear is 1100V or 1500V :x

      --
      Political debates have me rolling my eyes so much I think I got optical whiplash. I should sue. - Foamy The Squirrel
  4. T-shirts? by Anonymous Coward · · Score: 0

    Just thinking out loud here.

    .

  5. BS by user.aaaaa · · Score: 0

    BS as usual