We've told you how plastic can become fuel and form flexible batteries and transparent solar cells. Now, Wake Forest University scientists have created a new type of lighting made from thin layers of light-emitting polymer combined with nanomaterials that glow.
Based on alternating current (AC) field-induced polymer electroluminescent (FIPEL), the lighting device emits a soft, white light, unlike the harsh light from either fluorescents or LEDs. The light is similar to sunlight, and also flicker-free. The device itself is shatter-proof, avoiding broken glass and the hazardous mercury contained in compact fluorescent (CFL) bulbs.
Wake Forest University scientists have devised a shatterproof, white light, flicker-free lighting device based on field-induced polymer electroluminescent (FIPEL) technology. (Source: Wake Forest University)
The new lighting devices are also long-lasting, said David Carroll, professor of physics and director of the university's Center for Nanotechnology and Molecular Materials, in a press release. He owns one that has worked for about 10 years. The device has about the same efficiency as LEDs and is twice as efficient as CFLs. In addition to applications in office and home lighting, Carroll envisions the technology being used in large display lighting, such as signs on buses and subway cars, as well as store marquees.
The research team, which Carroll heads, made the lighting device from three layers of moldable, light-emitting polymer. Multi-walled carbon nanotubes (MWNTs) are dispersed in the active layer's polymer, sandwiched between two dielectric layers. The team described its work in an article in Organic Electronics.
According to the article:
An asymmetric device structure, using one dielectric layer, was used to study band alignment effects of carbon nanotubes in charge injection from a contact. The presence of MWNTs within the emissive layer facilitates effective internal charge generation in the symmetric devices, as would be expected if they acted as a charge source. The MWNTs effectively doped the polymer, modifying energy level alignment in the device and increasing field-induced polarization currents. Increase in light emission of five times is achieved in composite devices compared with the device without MWNTs.
The device is inexpensive to make, and the materials can be formed into many shapes and colors, from regular bulbs that fit household lamp and fixture sockets, to large 2-feet x 4-feet panels for office lighting. The team is working with a company to commercialize and manufacture the technology, and Carroll expects it to be available sometime this year.
This looks like a winner. Making a softer light than LEDs or CFLs would get a majority of the female market. My wife's biggest complaint about non-incandescent lights are the harshness of their light. As they say, happy wife happy life
The very fact that it has lasted ten years is fantastic. I'm use to screwing in a bulb and having it blow due to voltage surges. I went on the Wake Forest web site hoping to pull up specifications and none were there; i.e. watts, lumens, etc etc. This is a real breakthrough and certainly seems to be a viable alternative to what we have now in the market place. I think it is also gratifying to see nanotechnology applied to everyday uses. Great Article Ann and thank you for the information.
Scott, good point. I, too, hope that there aren't any hidden safety hazards associated with this new technology. Two things have disappointed me hugely about CFLs. First, the safety hazards associated with mercury, and second, the fact that they are meant to stay on for a long time, and not be switched on and off, as is usual in household, not office, use. That switching on and off lowers their lifespan tremendously. And of course, long lifespan was supposed to be part of the big draw in the first place--so you could amortize the much higher costs while you were saving energy.
I'm not sure how much of the world's electricity budget goes to lighting - but I'll bet it's a lot. If we can get our light for less energy, I'm all for it. Just as long as it doesn't pose a health hazard in the bargain (mercury in CFL's - I can't believe those are even allowed as a consumer item.)
William, thanks for your comments. FIPEL (field-induced polymer electroluminescent) is the technology discussed here, invented by Carroll of Wake Forest U, the head of the research team mentioned in this article. Since FIPEL hasn't been commercialized yet, I suspect the EL you're talking about is not at all the same thing.
Seems like this would be a good application for Christmas lights. When I was taking the tree down the other day it I thought about the market for wireless lights. Wifi Christmas lights that clip on. Program them any way you like or download you favorite after seeing it on utube. Write messages on the tree in lights for arriving guests.
My wife was house sitting in Princeton NJ, big house, big tree, and she heard a creak. Yes, the tree fell over as she was looking at it. All that heavy wire...
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