Slashdot Mirror

← Back to Stories (view on slashdot.org)

Chameleon Liquid Could Replace LCDs

Posted by Zonk on from the i'm-made-of-liquid-metal dept.

InvisblePinkUnicorn writes "NewScientist reports on a color-changing liquid that could cheaply replace the color components of standard LCDs. According to researchers at UC Riverside, the liquid 'contains tiny iron oxide particles coated with plastic. It is cheap and easy to make, and could also be used in flexible, rewritable, electronic paper.' From the article: 'The opposing forces of electrostatic repulsion [in the plastic] and magnetic attraction [in the iron oxide] result in the particles arranging themselves into an ordered structure, known as a colloidal "photonic crystal". The colloidal crystal reflects light because the spacing between neighboring particles in the structure is equivalent to the wavelength of light. Also, tuning the spacing slightly alters the exact wavelength, or colour, of light that is reflected. This can easily be done by varying the strength of the magnetic field applied to the crystal.'"

17 of 175 comments (clear)

  1. lets get to it by Anonymous Coward · · Score: 3, Insightful

    I'm tired of these new technologies that never make it out to the customer. Stop telling me what we could do, and do it already!

    1. Re:lets get to it by Aladrin · · Score: 4, Insightful

      The ones that 'never make it out' are the ones that are tragically flawed and you don't want, anyhow. Too expensive, too cancer-causing, too impossible, etc.

      On the other hand, if you don't want to know the cutting-edge tech that -might- come out soon, you are probably on the wrong site. Geeks tend to value new ideas, even if they are impractical.

      --
      "If you make people think they're thinking, they'll love you; But if you really make them think, they'll hate you." - DM
    2. Re:lets get to it by Glith · · Score: 4, Insightful

      Of course we do. New, practical ideas don't come into existence without brainstorming through plenty of new, impractical ideas.

    3. Re:lets get to it by daskinil · · Score: 2, Insightful

      I agree, its not that these technologies never come out either, but the upstream technologies and research often take 6-10 years to be engineered into products. So the consumer doesn't see technology thats developed today until 2015 or so.

    4. Re:lets get to it by catbutt · · Score: 4, Insightful

      Have you considered not reading technology sites and just going to the mall, if all you are interested in is finished products?

  2. Magnets by hack++slash · · Score: 3, Insightful

    I remember having fun with powerful magnets and CRTs, does this mean LCD panels made with this new liquid be susceptible to magnetic fields too?

    --
    To do something right, you often have to roll up your sleeves and get busy.
    1. Re:Magnets by Anonymous Coward · · Score: 1, Insightful

      . . . does this mean LCD panels made with this new liquid be susceptible to magnetic fields too?

      From the article: 'The opposing forces of electrostatic repulsion [in the plastic] and magnetic attraction [in the iron oxide] result in the particles arranging themselves into an ordered structure, known as a colloidal "photonic crystal".

      I'm not sure. What do you think?
  3. Re:Response time? by MontyApollo · · Score: 2, Insightful

    Slow response time would be fine for websurfing, photo albums, PIMs, etc. The display could be used for certain PDA's, smart phones, electronic books/newspapers, etc... I think it still would be cool.

  4. Probably not. Too many electromagnets by Animats · · Score: 4, Insightful

    It sounds cute, but it's another minor advance in materials science, and a long way from being a new display technology.

    The basic problem is that it requires a big array of electromagnets, one per pixel. Fabricating large arrays of electromagnets is expensive; it's hard to fabricate coils using an IC process. And it doesn't scale down well; tiny coils are tough to make. It's also hard to contain a magnetic field in a small space. So electrostatic devices, like LCDs, and emission devices, like plasma panels, tend to win out.

    Previous technologies shot down by this fact include magnetic bubble and magnetic core memories. They worked, but they never got either cheap or tiny.

  5. Color changes with viewing angle? by G4from128k · · Score: 2, Insightful

    The variation in color around the tubes shown in the photos seem to suggest that the color is angle-dependent (not surprising given the photonic crystal design). One would see a redder (longer-wavelength) when viewing straight on to the panel than from any angle to the side. This is NOT acceptable for most applications.

    I do hope they can create angle-independence -- perhaps microlenses or shaping of the cell well would help in some way.

    --
    Two wrongs don't make a right, but three lefts do.
    1. Re:Color changes with viewing angle? by Anonymous Coward · · Score: 2, Insightful

      No, I think it's because the field strength varies across the tube. They just put magnets behind the tubes (you can see one of them) -- not very precise or high-tech, but it shows how simple the technology is, which is a good sign IMO.

  6. Re:What if you dropped a magnet on it? by SQLGuru · · Score: 2, Insightful

    And a magnet didn't make your CRT go all "wonky" rainbow colored?

    Layne

  7. Re:Need a heck of a magnetic field controller.. by Anonymous Coward · · Score: 1, Insightful

    Its one thing to move a magnet to and from a tub of liquid and watch it change colors, which is cool, but its another to have millions little magnetic fields inside of a display, not only switching on and off, but varying in intensity.


    It's one thing to detect a magnetic field, quite another to detect millions of them spinning on platters! at 15,000 rpm!
  8. Re:Response time? by tomstdenis · · Score: 1, Insightful

    I love you.

    --
    Someday, I'll have a real sig.
  9. Re:Response time? by SnowZero · · Score: 3, Insightful

    As opposed to an LCD which truly is at a given level, there is no fade out. Wrong. Go to Tom's hardware and look at any of their LCD reviews. The response curve is not square, nor is it likely to be anywhere near the quoted speed, which is usually describing the best case rather than the worst case. You're also neglecting the common "overdrive" method used to get sub "16ms" response times, which means the LCD takes a long time to actually converge on a level; Contrary to your claim, for video it really is almost never is at the right level, rather it wobbles around it and looks grainy. So, CRTs are still better at response time (in particular rise time) and flatness of a shade, but suck for all the other reasons that CRTs do (size, weight, flicker, etc). It's a trade-off, please don't try to pretend it isn't.

    If you want a good waveform, you'll need an OLED. Those can respond in a few ms from/to any brightness level (just like an LED). Once those take off in popularity, they will probably rule the roost for gaming and video, if not everything.
  10. The implications... by nadamucho · · Score: 2, Insightful

    Another issue with this, which has yet to be addressed, is that the pixels in this display aren't made up of RGB subpixels. This means that when color is processed by the computer, it needs to be transmitted as a color, rather than shades of RGB. Should this technology come to market, it seems that it would be too impractical to take an RGB signal from the computer, analyze it, convert it to a color, and then display it. It would require an entirely new video driver (possibly new graphics hardware) to output a "color" signal, rather than an RGB signal.

    As far as brightness is concerned, this is "easily" solved by backlighting the display with white OLEDs. This way, you have a color and a brightness, everything you need for a pixel.

  11. Re:Response time? by eggnoglatte · · Score: 2, Insightful

    Sorry, you are wrong on two counts:

    a) modern LCD panels do not have a square pulse. In order to achieve fast switching times, the frame-to-frame differences are actually overdriven. Say you are currently at pixel value 100, and want to go to 150. You would actually drive the pixel at 170 or so, such that at the end of the new frame, the time-averaged transmission over the frame interval is the desired 150. The numbers are made up of course, but the principle holds.

    b) CRT phosphors have a non-zero decay period, but they are actually fairly fast. So much so, that you can measure easily where the electron gun is at any given point in time. This is how light pens work (used to be the input device of choice before the mouse and touchscreens, now http://www.fastpoint.com/ seems to be the only manufacturer), or how security researchers manage to read the screen content from a reflection on the wall: http://www.cl.cam.ac.uk/~mgk25/ieee02-optical.pdf