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Stretchable OLEDs for Displays, Lighting

9/27/2013 00:00 AM EDT
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LarryM99
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Feedback or Silly Putty?
LarryM99   9/27/2013 7:35:41 PM
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This is cool! Are they anticipating incorporating feedback as to the distortion so that the image can be adjusted or does it just distort? I can think of applications for both cases, but it seems like serious applications would be likely to benefit from the feedback. I am thinking of a screen folded into 1/4 size initially. Unfold it and the image scales accordingly to take up the entire view. Stretch it horizontally and it expands in that dimension with a wider image.

R_Colin_Johnson
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Re: Feedback or Silly Putty?
R_Colin_Johnson   9/27/2013 7:58:29 PM
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Good ideas all, thanks, but the researchers biggest priority right now is finding a stretchable encapsulaiton method to protect it from exposure to air--which deteriorates all OLEDs. And secondly, to engineer a flexible thin-film transistor (TFT) so the display can be made active--the prototype is passive. Others are also working on these problems as well, in particular professor Zhenan Bao at Stanford University is also working flexible TFTs.

 

 

stcarmic
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Re: Feedback or Silly Putty?
stcarmic   10/22/2013 10:41:35 AM
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Note that this demo is NOT actually an OLED. It's a "LEC" or "LEEC". https://en.wikipedia.org/wiki/Light-emitting_electrochemical_cell  

Pei said it in the article: "The second key development is an OLED architecture that we call light-emitting electrochemical cell [LEC]. The LEC devices use a thin luminescent layer that is actually a mixture of electronic semiconductor and an ionic conductor." These devices are not like traditional colour display pixels; they don't have addressability and they don't have multi-colours (i.e. RGB) so cannot display any reasonable gamut of colour range. So these are essentially lighting panels, and the particular ones shown here are yellow. The light emission comes from the polymer, phenyl substituted poly(para-phenylene vinylene) known as "Super Yellow," (you can purchase it and make your own). Even though they show "pixels", note they are not able to light them individually, and a screen made of these would really resemble something very old! -> https://en.wikipedia.org/wiki/Monochrome_monitor

 

Caleb Kraft
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Re: Feedback or Silly Putty?
Caleb Kraft   9/28/2013 9:57:47 AM
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The unfolding scenario is completely feasible, however making the image adjust to a stretched screen will require some magic.

When you stretch the screen, you're not increasing the resolution, merely distorting the existing pixels (making them longer, or possibly just spreading them out).

While it would be theoretically possible to simply lower the resolution of the image at that point, you would have to drop to the lowest resoltution capable at that moment. Basically, your image would get blurrier the bigger you stretched the screen if you wanted to maintain the initial aspect ratio.

Kinnar
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Seems that again a new era is about to start
Kinnar   9/28/2013 4:43:46 AM
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CRTs, then LCD/LED/OLED and now it seems that flexible displays will be in the retail market very soon, and that will again start a revolutionary thing, really a remarkable work and achievement by UCLA scientists.

_hm
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How to define optical properties?
_hm   9/28/2013 8:54:18 AM
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This is looks very good news and it has so many new applications. However, in more demanding applications, optical properties are also equally important. Once OLDEs are stretchable, how one defines optical properties? It must be challenging for designer and user.

 

wilber_xbox
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Re: How to define optical properties?
wilber_xbox   9/29/2013 1:41:29 PM
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_hm, which optical properties are you talking about? For comsumer applications, the optical properties which need to be there are related to image distortion, blurr, sharpness, color contrast etc. Until we solve these problems in stretchable devices we cannot introduce stretchable or flexible displays but i donot know how much progress has been there already.

_hm
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Re: How to define optical properties?
_hm   9/29/2013 2:21:44 PM
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@Wilber: Yes, I am wondering about similar properties and user experience.

 

Caleb Kraft
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damage
Caleb Kraft   9/28/2013 9:59:19 AM
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While the idea of a foldable and stretchable screen is neat, I think the biggest impact here will be durability. A flexible screen isn't going to break when you drop it. When your phone flexes, you don't risk a shattered screen.

R_Colin_Johnson
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Re: damage
R_Colin_Johnson   9/28/2013 12:22:18 PM
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@Caleb Kraft "the biggest impact here will be durability"

Brilliant observation! I had not thought of the durability aspect, probably because the researchers did not mention it, but I think you are right. Everybody wants a more durable display, and making one would merely mean using these more durable materials, whereas a display that is intended to be viewed in its stretched state has the engineering hurdles that you and others in this thread have mentioned.

Caleb Kraft
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Re: damage
Caleb Kraft   9/28/2013 12:38:02 PM
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yeah, imagine how many screens were smacked by wiimotes that could have survived if they weren't so brittle!

elctrnx_lyf
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Re: damage
elctrnx_lyf   9/29/2013 11:53:11 AM
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We are going to see all new range of lifestyle devices by using these latest technologies.

wilber_xbox
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Re: damage
wilber_xbox   9/29/2013 1:38:05 PM
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I might be wrong but i think glass is used because of the touch screen purpose and not due to limitations of the LED/OLED. But if we can basically provide two most impotant aspect (transparency and conductivity) in stretchable material then we will have undistructable or more durable screen.

stcarmic
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Re: damage
stcarmic   10/22/2013 10:28:21 AM
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Q.Pei's group is not the only one working on this problem, but they are the biggest and so they get the press. Check out a stretchable oled-type device (LEEC) that works at room temperature published from 2012  http://onlinelibrary.wiley.com/doi/10.1002/adma.v24.20/issuetoc   .

Very rough prototype of a "pixel" stretching can be found here:

 http://www.youtube.com/watch?v=3ENjrtbWGaM

Also this year the same group from Canada published a coating that adds transparent electrical function with great flexibility, AND is very durable! http://pubs.acs.org/doi/abs/10.1021/am402847y

Commercial products are years away of course, but some very interesting research is happening in this field!

Being_On_Board
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Display Prototype and Potential Applications?
Being_On_Board   9/30/2013 9:33:16 AM
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This article appears to be about a research project and a working prototype - producing a reliable, high volume product that is commercially viable seems a long way off. Could someone enlighten me as to the potential real-world applications that flexible displays will find?

R_Colin_Johnson
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Re: Display Prototype and Potential Applications?
R_Colin_Johnson   9/30/2013 12:05:19 PM
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Yes, this particular research project is a proof-of-concept, but the market for flexible and curved displays is estimated to grow from $388 million today to $27 billion over the next decade. The flexible display applications listed in the  Touch Display Research report for today include Lexar's memory devices using flexible electrophoretic displays from E Ink, flexible LED displays used in Nike+ FuelBand and flexible LED signages used in public venues. The report speculates on all sorts of flexible wearable displays for the future, such as smartwatches that wrap aroung the wrist to provide more surface area.

Being_On_Board
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Re: Display Prototype and Potential Applications?
Being_On_Board   9/30/2013 12:45:23 PM
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I think that until the technology - whatever that maybe - for curved and flexible displays becomes commercially viable the the discussion of which applications will benefit is somewhat premature. Sure, flexible display technology will come at some point in the future...consider that the first LCDs were prototyped 40-50 years ago and perhaps only now have they become ubiquitous.

chanj0
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Re: Display Prototype and Potential Applications?
chanj0   9/30/2013 2:20:02 PM
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I can see a lot of applicable area and I do agree that the talk of application may be premature until the technology is commerically viable. Nonetheless, who knows how soon the technology can be commerically viable? I have noticed lately that technology is widely available sooner than before. Just look at OLED itself, the pace is far exceeded that of LCD. The market welcomes small OLED display on mobile device, then large TV.

wilber_xbox
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Re: Display Prototype and Potential Applications?
wilber_xbox   9/30/2013 3:05:20 PM
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chanj, i agree that some technologies are faster to integrate in consumer market but other such as 3D LED have failed despite all the hype and maturity. Sometime the price at which the technology is sold is not enough and technology support and peripherial support is more than necessary.

docdivakar
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Re: Display Prototype and Potential Applications?
docdivakar   9/30/2013 3:58:43 PM
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It seems like the technology shows good promise. There are many open  questions for this before product designs can start. I would be curious to know if there are any optical behavioral shifts with stretch ratios? And does it vary with time?

We are witnessing another type of display technology take shape -light-emitting electrochemical cell (LEC)...

MP Divakar

R_Colin_Johnson
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Re: Display Prototype and Potential Applications?
R_Colin_Johnson   9/30/2013 5:09:53 PM
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@docdivakar I would be curious to know if there are any optical behavioral shifts with stretch ratios? And does it vary with time?

I believe most of the stretching durability tests were performed on the light panel rather than the display prototype, so no data on optical behavior shifts or time variance properties yet. Also the researchers next concentration is finding an encapsulation method that can stretch as easily as the LEC.

docdivakar
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Re: Display Prototype and Potential Applications?
docdivakar   9/30/2013 8:49:24 PM
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@R_Colin_Johnson  Thanks for the follow up. I suppose one can compensate algorithmically any chromatic shift with a corrector.

It seems like the UCLA team is focusing on the right challenge to work on in the encapsulation method.

MP Divakar

stcarmic
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Re: Display Prototype and Potential Applications?
stcarmic   10/23/2013 9:35:16 AM
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I'm surprised that the Samsung YOUM has not popped up here anywhere with all this talk of flexible displays! This video is from Jan 2013, and showcases an absolutely amazing flexible OLED colour display. At the 0:40 mark prepare to be astounded! http://www.youtube.com/watch?v=N3E7fUynrZU . The main problem is of course, the encapsulation. The lifetimes on these are shorter than they will be once we have flexible/stretchable encapsulation. For curved displays they can still use glass, but how many of us want to fit a 72" curved display in our home? http://www.dailytech.com/Samsungs+55inch+Curved+OLED+TV+Ships+for+Only+9000/article33166.htm

 

R_Colin_Johnson
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Re: Display Prototype and Potential Applications?
R_Colin_Johnson   10/23/2013 9:40:42 AM
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Thanks for including the Samsung link--I've been meaning to include them in the discussion--and you're right on both counts: their demo was very impressive, but of course the encapsulation technology will be the critical factor in how soon they can come to market.

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