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Technology Science

Nanotech Could Make Incandescent Light Bulbs As Efficient As LEDs (sciencemag.org) 338

sciencehabit writes: Thomas Edison would be pleased. Researchers have come up with a way to dramatically improve the efficiency of his signature invention, the incandescent light bulb. The approach uses nanoengineered mirrors to recycle much of the heat produced by the filament and convert it into additional visible light. The new-age incandescents are still far from a commercial product, but their efficiency is already nearly as good as commercial LED bulbs, while still maintaining a warm old-fashioned glow.
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Nanotech Could Make Incandescent Light Bulbs As Efficient As LEDs

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  • Great! (Score:5, Insightful)

    by Anonymous Coward on Monday January 11, 2016 @05:49PM (#51281889)

    I can't wait to get back to the days of changing each light bulb in my house a couple of times each year.

    • The reason you are changing the bulbs so frequently is because the factories have engineered them to fail. When they were selling the bulbs for 0.25 a-piece, making them last 100 years would have been financial suicide.

      Filament bulbs can last 5+ years, if you engineer them to, especially at the "warmer feeling" lower temperatures.

      • They'll also last far longer if you undervolt them.

        Fun fact: The EU incandescent lightbulb ban only affects bulbs of certain shapes, so retro style carbon filament-style (without an actual carbon filament) hipster bulbs that are even less efficient than normal incandescent bulbs have gained popularity 'round these parts
      • Re:Great! (Score:5, Informative)

        by Firethorn ( 177587 ) on Monday January 11, 2016 @06:22PM (#51282209) Homepage Journal

        Filament bulbs can last 5+ years, if you engineer them to, especially at the "warmer feeling" lower temperatures.

        They can make them last centuries. The current longest lasting filament bulb is at 114 years and over 1M hours.

        The 'trick' is that the heavier and cooler the filament it, the longer it lasts - but the less efficient it is at making light.

        So a .25 cent bulb that is engineered to last about 3-6 months in normal usage is at a sweet spot - you could make it last longer, but it'd use more than .25 cents worth of extra electricity in that time. So it's cheaper to make it a bit more energy efficient at the cost of life span.

        Of course, equations change as the price of electricity goes up.

        • Re: (Score:3, Interesting)

          I'm old enough to remember taking our burnt out bulbs down to the local Edison to exchange for free new ones.

          Needless to say they lasted a hell of a lot longer.

          Then Phillips sued, arguing restraint of trade, and won, and that was when I first encoutered rent seeking.

          • Re:Great! (Score:5, Informative)

            by Firethorn ( 177587 ) on Monday January 11, 2016 @07:52PM (#51282949) Homepage Journal

            I'm old enough to remember taking our burnt out bulbs down to the local Edison to exchange for free new ones.

            Electric company, I take it? Consider what I said, the electric company could have been 'rent seeking' in a completely different way than Phillips. Sure, they're perfectly happy handing you 75W bulbs that last darn near forever, but produce the same amount of light as the Phillips 60W that doesn't last as long.

            That extra 15W could garner them an extra $13/year if the light's on all the time. Not bad for a giveaway of an under 25 cent bulb, bought in bulk. Cost differences for varying light output and longevity amount to a rounding error given how small the tungsten element is and that 'power' depends on the shape. Thicker element = longer lasting higher power bulb. Shorter element = shorter lasting higher power bulb. Thinner/longer = lower power. Balance to fit.

      • by tlhIngan ( 30335 )

        The reason you are changing the bulbs so frequently is because the factories have engineered them to fail. When they were selling the bulbs for 0.25 a-piece, making them last 100 years would have been financial suicide.

        Filament bulbs can last 5+ years, if you engineer them to, especially at the "warmer feeling" lower temperatures.

        Not to mention I the early 20s the Phoebus Cartel [wikipedia.org] got together to deliberately limit the lifespan of lightbulbs to around 1000 hours or so. The argument was making them last longer

        • Back when bulbs cost more than the labor to change them, that made some sense overall. It is a great example of "free enterprise" gone wrong in today's world.

    • And here I bought these vintage-incandescent LED bulbs with warm glowy yellow "filaments" for nothing. They were right on the shelf and everything, and I didn't even read a cool headline about 'em. What a rip-off! ;)

    • I can't wait to get back to the days of changing each light bulb in my house a couple of times each year.

      I've typically found that they either fail quickly or last a really long time...still, avoiding CFLs though and going straight to LEDs. I still buy incandescent though when I can for lamps, etc as they just work better.

      We have some CFLs that we got from Sam's Club for $0.99 for a pack of 10 or so; not a big fan and they cause a lot of problems, especially with lamp shades that expect a certain bulb size, or if one of the kids knocks it over and breaks the bulb (releasing the mercury); LEDs and incandesce

  • The point of the point of the invention is to reflect the infrared light back at the filament, so the warmth should be pretty much absent if they succeed.

    • Re:Not a "warm glow" (Score:5, Informative)

      by Junta ( 36770 ) on Monday January 11, 2016 @05:57PM (#51281963)

      They mean warm in the sense of color temperature (yellowish).

    • As others have mentioned: color, not actual heat produced.

      One thing that LEDs aren't emulating (yet) is the nature of a dimming incandescent where the color gets more yellow-red as you dim the light. LEDs will pick a "color temperature" and that's it, regardless of dimming. I think this nano-enhanced incandescent will probably do the color shift with dimming thing. Now, can they make it last a couple of years and cost less than LED bulbs?

      • Why would you want the bulb to change color when it is dimmed? I ever saw that as a feature on the dimmers I've used.

        • by AndroSyn ( 89960 )

          When you dim an LED bulb, the amount of light reduces, however the color temperature is the same. The best thing I can compare it to is moonlight. An incandescent when you dim it, it runs cooler and as a result it goes to more of a red color instead of the yellow white color it normally runs at. Most people generally find this shift towards red rather pleasing when dimming a light bulb. It's not a "feature" of the dimmer, but a function of the physics of an incandescent bulb.

          • by zieroh ( 307208 )

            An incandescent when you dim it, it runs cooler and as a result it goes to more of a red color instead of the yellow white color it normally runs at.

            A shift toward red is warmer, not cooler.

            Most people generally find this shift towards red rather pleasing when dimming a light bulb.

            Citation needed. Actually, no, don't bother. That's just bullshit.

            It's not a "feature" of the dimmer, but a function of the physics of an incandescent bulb.

            It's not a feature of anything. That's a bug.

            • by AndroSyn ( 89960 )

              A shift toward red is warmer, not cooler.

              Color temperature yes, thermal temperature, no. They're sort of backwards from each other :(

              Most people generally find this shift towards red rather pleasing when dimming a light bulb.

              Citation needed. Actually, no, don't bother. That's just bullshit.

              It's a pretty subjective thing, I agree. It's the same subjectiveness that most people like "warm white" bulbs(2000-3000K) instead of daylight(5500K or above).

              It's not a "feature" of the dimmer, but a function of the p

            • by lgw ( 121541 )

              Citation needed. Actually, no, don't bother. That's just bullshit.

              Never had a romantic evening? I mean, yes, this is Slashdot and such lack of experience is expected, sure, but usually people at least understand the concept.

            • by cdrudge ( 68377 )

              An incandescent when you dim it, it runs cooler and as a result it goes to more of a red color instead of the yellow white color it normally runs at.

              A shift toward red is warmer, not cooler.

              I think he means that when you dim an incandescent, it's thermodynamic temperature is cooler. The filament shifts from a shade of white towards the red, creating a color temperature that is warmer.

          • When you dim an LED bulb, the amount of light reduces, however the color temperature is the same.

            No it isn't. One of many reasons displays use crappy PWMs to dim backlights.

        • by markus ( 2264 )

          There actually is a good argument to be made for changing the color temperature with the amount of light output.

          Take a look at the Kruithof Curve: https://en.wikipedia.org/wiki/... [wikipedia.org]

          Humans are used to see higher color temperature (i.e. more bluish light) in brighter environments. This naturally mimics the light around noon time. We are also used to see lower color temperatures (i.e. more yellow'ish light) in darker environments. This would mimic the light during dawn and dusk.

          If the color temperature indoors

        • I can't give a citation to this, but I did read something to this effect before: The mind / eye is calibrated for color temperature vs light intensity. They share a linear relationship (maybe not linear but you get the idea. Higher intensity = higher color temperature).

          Going 200 years ago, before electric light, at the brightest point in the day (noon) the color temperature is 6000K+. At sunrise/ sunset (when the intensity low) it is 1850K. A candle or fire would be 1700K at an extremely low intensity.

          So a

      • As others have mentioned: color, not actual heat produced.

        One thing that LEDs aren't emulating (yet) is the nature of a dimming incandescent where the color gets more yellow-red as you dim the light. LEDs will pick a "color temperature" and that's it, regardless of dimming.

        Not necessarily true. I recently bought some dimmable LED bulbs that feature getting redder as you dim them. I assume they do this by monitoring the incoming waveform and tweaking the power to different colored elements inside.

        I didn't even notice the feature on the package until after I got them home, but I tried one in a dimmable fixture to test it out, and it worked better than I expected (although the bulb still couldn't be dimmed down quite as far as a real incandescent before dropping to zero output).

        • As others have mentioned: color, not actual heat produced.

          One thing that LEDs aren't emulating (yet) is the nature of a dimming incandescent where the color gets more yellow-red as you dim the light. LEDs will pick a "color temperature" and that's it, regardless of dimming.

          Not necessarily true. I recently bought some dimmable LED bulbs that feature getting redder as you dim them. I assume they do this by monitoring the incoming waveform and tweaking the power to different colored elements inside.

          I didn't even notice the feature on the package until after I got them home, but I tried one in a dimmable fixture to test it out, and it worked better than I expected (although the bulb still couldn't be dimmed down quite as far as a real incandescent before dropping to zero output).

          Had to happen, eventually - I haven't seen those yet. We've got probably too many lights in our house (PO installed 4 ceiling cans in each bedroom, 12 in the kitchen), so we tend to run our dimmers way down - and that's kinda funky looking with the un-changing color bulbs.

  • by CastrTroy ( 595695 ) on Monday January 11, 2016 @05:55PM (#51281939) Homepage

    What's the lifetime of the new incandescent bulb? Do they still burn out as fast as they used to? Or does recycling the heat cause them to take longer to burn out. The major advantage I find in LEDs is that they last a long time. And with the plummeting prices (picked some up for $3.50 a piece at Walmart last week), It's going to be hard for incandescent bulbs to compete. If this was such a good solution, it could probably be used for LED lights as well, since they throw off a non-negligible amount of heat as well.

    • Re: (Score:3, Interesting)

      If this was such a good solution, it could probably be used for LED lights as well, since they throw off a non-negligible amount of heat as well.

      Unfortunately that is mostly in the form of heating of the LED semiconductor die, relatively little in the form of infrared radiation. So the method presented in the article would have only a small effect on a LED's efficiency (if at all).

      And yes, there's a relation between the temperature of an object and how much IR it radiates. But unlike glowing-hot-wires, operating temperatures of LEDs are not in a range where this is a big factor.

    • Keep buying those Wal-Mart bulbs and tell me how your actual lifetime performance works out. The cheap CFLs burned out almost as fast as incandescents, while still costing 4-20x as much (yeah, $3.50 is cheap for an LED bulb, but try equating that to the 8 for $1 cheap incandescents...)

    • What's the lifetime of the new incandescent bulb? Do they still burn out as fast as they used to? Or does recycling the heat cause them to take longer to burn out.ll.

      Cycling is the greatest contributor to degradation, but the quality of bulb varies so much that their is no good answer. As you say, LED bulbs have now gotten cheap enough that its a no brainer. But we don't know the lifetime yet. While the LED chips are likely going to last, the cheap drivers are more likely to be what fails. I have my doubts they'll last as long as the claims.

    • What's the lifetime of the new incandescent bulb? Do they still burn out as fast as they used to? Or does recycling the heat cause them to take longer to burn out. The major advantage I find in LEDs is that they last a long time. And with the plummeting prices (picked some up for $3.50 a piece at Walmart last week), It's going to be hard for incandescent bulbs to compete. If this was such a good solution, it could probably be used for LED lights as well, since they throw off a non-negligible amount of heat as well.

      It'll be interesting to see how LEDs fare in a couple years. When CFLs first came out, they really did last as long as advertised, but as time went on they started to burn out faster and faster. Now they don't last any longer than the old incandescents did. One of my three original CFLs purchased in the 1990's is still working. CFLs I purchase nowdays last maybe a year to 18 months.

      I just purchased my first LED three months ago. As the CFLs fail I intend to replace them with LEDs. I expect the first b

    • by GPS Pilot ( 3683 ) on Monday January 11, 2016 @09:22PM (#51283489)

      If this was such a good solution, it could probably be used for LED lights as well

      No. Incandescent filaments have to be hot to produce light, but with its entirely different mechanism, reflecting infrared back onto a light-emitting diode will not help it produce more light. Heat is NOT good for the diode. LED bulb designs actively do the opposite of these nanomirrors: they transfer heat away from the diode. (You may have noticed the fins on some LED bulbs. Their purpose is to radiate heat and keep the diode cooler.)

    • by Lehk228 ( 705449 )
      i got a bunch on sale at lowes for 1.95 each in 2 or 6 packs
  • Interesting acheivement, though I wonder at any help for lifespan. I'd rather put in LED bulbs that will probably outlive the rest of the house...

    • outlive the rest of the house

      Not in my experience. But I'll continue to use them for efficiency reasons.

      • Yeah, I put a $20 Cree in a hard-to-access location because I was tired of getting the ladder every three years and climbing up there. Now where is my Home Depot reciept from last April?...

        • by Guspaz ( 556486 )

          I hope you kept that receipt, because I have not found Cree bulbs to be any more reliable than incandescents.

      • I have found that installing led bulbs into existing fixtures is a hit and miss affair. And it seems to have more to do with the fitting than the bulb as I have identical bulbs in multiple places but the same fittings always fail.

        That said I have gone around and replaced all my ceiling fittings with sealed LED fittings and have not had a single one of those fail.

  • Thomas Edison didn't invent the electric incandescent light bulb, he developed an electric incandescent light bulb.
    • by PRMan ( 959735 )
      He developed the one that could last long enough not to be merely a science experiment. This is EXTREMELY important.
    • Roughly speaking, he was to light bulbs what Henry Ford was to automobiles. After all, he developed the first light bulb to be economical for mass use.

      Before that, they did have electric lights, but they were carbon arc lamps - too much light and horrible color rendering for routine use in a house.

    • Thomas Edison didn't invent the electric incandescent light bulb, he developed an electric incandescent light bulb.

      The long-lived high-impedance Edison lamp could be wired in parallel --- which is essential if you want to light up a city and keep it lit and not --- however briefly --- a single Charlie Brown Christmas tree.

      Edison was a system-builder.

      Power generation. Distribution networks. Wiring standards. Switches. Fuses. Plugs and sockets. Training schools for a new generation of electricians.

  • I like my LEDs... (Score:5, Insightful)

    by blankinthefill ( 665181 ) <blachancNO@SPAMgmail.com> on Monday January 11, 2016 @06:01PM (#51282015) Journal

    Aside from questions of longevity, I honestly much prefer the availability of light color options that LEDs provide. After getting several LEDs that are substantially cooler in color than normally available incandescents/CFLs, I never want to go back. Add to that the fact that I can GET warmer colored LEDs if I desire, and the fact that I can use LED lights that package other abilities into their package (like wireless speakers), and I just don't see the consumer draw other than some rose colored glasses. (Maybe for dimmable bulbs, which I know LEDs struggled with for awhile but they seem to have overcome that also... This also ignores the brightness of the lightbulb, as LEDs have just generally been brighter [a good thing imo] than comparable incandescents and CFLs in my experience. Maybe the new tech solves that, but still probably not worth it as a consumer is my feeling.)

    • by PRMan ( 959735 )
      I have had fantastic dimmable LEDs on my chandelier over my dinner table for years now.
    • It's nice they've found a way to boost traditional bulb efficiency, but from my armchair... based upon what I read they're simply capturing the infra-red (heat) and boosting its frequency by placing a filter/mirror device in front of the filament. I'm not sure that this technique wouldn't be applicable to LEDs as well.
    • by Prune ( 557140 ) on Monday January 11, 2016 @09:17PM (#51283461)
      I hate LEDs. Their color rendering index is usually below 90, with the fanciest available at 93 -- still quite terrible if you care that colors of objects from clothes to decorations to paintings look anything like they do under sunlight. There's not going to be much improvement on this parameter as well, because the uneven spectrum LEDs emit, regardless of overall color temperature (what white point they're matched to) makes it impossible to filter effectively. Incandescents, on the other hand, have a smooth blackbody spectrum that's very easy to filter, and high end incandescent bulbs can be matched to duplicate solar spectrum.
      • Take a CD or DVD and hold it so you can see a diffraction spectrum. Incandescents have a continuous spectrum, and so do the LED-phosphor bulbs used for room lighting, although the latter is likely to be stronger in the blues. Every fluorescent I've seen has actual gaps in the spectrum.

        Although it's a start, CRI is not a good measure; it's possible for instance to combine several monochromatic sources to produce a CRI of 100. Something better is needed.

  • The question isn't just whether they'll be as efficient as LEDs. The question is whether they'll last as long and cost as little.

    Frankly, for most people, what they liked about incandescents was their cost. I seriously doubt that anything that requires "nanoengineered mirrors" will cost $2.50 for a pack of 10.

    Dan Aris

    • by PRMan ( 959735 )

      Then people can't math.

      Sure, the BULB ITSELF was a quarter instead of $5-$10. But then it used $1 a month more than the replacement. Within 10 months, you were already paying more. Plus, good luck on that quarter incandescent lasting more than 1 year. So now you are paying 25 a year on top of it.

      • Sure, the BULB ITSELF was a quarter instead of $5-$10. But then it used $1 a month more than the replacement. Within 10 months

        that fits well in the current credit based economy. people don't pay up front, they buy on credit and then pay the interest.

  • by Anonymous Coward on Monday January 11, 2016 @06:02PM (#51282021)

    There are some crazy innovations happening in LED lighting. To the point where stock on shelves is becoming obsolete in a matter of months.

    All white LEDs are essentially florescent lamps. - A blue-range LED excites a phosphor that makes white light. You can tune the phosphor mix to get whatever color range you want. "Warm" Led lights are completely indistinguishable from incandescent, and in may cases can be "Warmer"

    So basically you have an emitter with a glob on tob.

    In the past everyone was focusing on getting the emitter more powerful, and putting one or two in a light.

    That approach is completely obsolete - Too much heat in a tiny space, extremely high drive current requiring more expensive power supplies, light comes from a single point source. (Single emitter is good for some applications but for home lighting its not great)

    Now they've developed chip-on-glass techniques that lay down lots of tiny LEDs on a strip of glass which are all then wired in serries, then are covered in a soft polymer that contains the phosphor. The polymer both protects the chips and their wiring while providing a large surface area to emit white light.

    The strip arrays are cheap to make (completely automated) and guess what happens when you power a bunch of strips in series (About 80-200 chips at a time)? You can drive it at like 60-100 volts. At that voltage the power supplies are CHEAP because you're only drawing a few hundred ma. Everything gets cheaper and more efficient.

  • by 140Mandak262Jamuna ( 970587 ) on Monday January 11, 2016 @06:07PM (#51282063) Journal
    By the time nano tech incandescent are ready for the market, the market will have nano tech LEDs which would be even more efficient than it is today. It is like the gallium-arsenide that is going to replace silicon any time now, except by the time GaAs improves, silicon improves too...Or the solid state drives making spinning disks of rust obsolete... By the time solid state achieves a breakthrough, the rust disks are already meeting matching it in price. Only when people are willing to pay premium for the *other* advantages of solid state drives, lower power consumption, silence, small form factor, etc they are viable.

    So let us give these guys a well deserved PhD or Masters as the case may be and move on...

  • So? (Score:2, Insightful)

    by bigsexyjoe ( 581721 )

    The right-wing blowhards on the radio will still complain about having to use them.

    • Re: (Score:2, Flamebait)

      by ScentCone ( 795499 )

      The right-wing blowhards on the radio will still complain about having to use them.

      Is that anything like left-wing blowhards on Slashdot complaining about what other people say?

  • while still maintaining a warm old-fashioned glow.

    Is this old fashioned warm glow really better, or is it just more familiar? (much like the "warmer" sound from vacuum tube amplifiers that some people prefer)

    I've used CFL's for over a decade, and started moving to LED's about 2 years ago, and I really have no problem with the LED light - I use "warm" 2700K LED's almost everywhere and they are fine. I still have a rarely used desk light with an incandescent, and I don't think it puts out any better light than the LED's.

    • Personally, I want a white light during the daytime, but a yellower light in the evening. It does less to mess with my circadian rhythm that way. So I want white lights at work, but my lights at home should be warmer (in the color sense, meaning lower color temperature).

      • by hawguy ( 1600213 )

        Personally, I want a white light during the daytime, but a yellower light in the evening. It does less to mess with my circadian rhythm that way. So I want white lights at work, but my lights at home should be warmer (in the color sense, meaning lower color temperature).

        I think Phillps [philips.com] has just what you need.

  • by AnotherBlackHat ( 265897 ) on Monday January 11, 2016 @06:55PM (#51282509) Homepage

    From The Fine Article;

    ... ultimately improved the efficiency of the bulb to 6.6% ...

    6.6% is 45 lumens per watt.
    Pardon me while I yawn.
    This tech might lead to something interesting, but so far, not so much.

    The commercially available Cree soft white 4-flow A19 bulb [homedepot.com] is 12% or 82 lumens per watt.

    There are LED modules [cree.com] for sale that are over 200 lumens per watt.

    In the lab, 303 lumens per watt (44%) has been achieved. [cree.com]

  • This is good news for those guys at sideshows who eat light bulbs: I can't see how the new LED bulbs could possibly be as tasty or nutritious.

  • Because he is dead and will not be able to falsely claim credit for it's invention. http://www.cracked.com/article... [cracked.com]
    • Because he is dead and will not be able to falsely claim credit for it's invention.

      Still, at least Edison understood the difference between the contracted "it's" and the possessive "its."

  • Why would anyone prefer warm yellow light? That was a byproduct of incandescent light, not a design choice. I for one hate the way it made everything look dirty and yellow. Give me white light (3500-4000K) any time.

  • by Mike Van Pelt ( 32582 ) on Monday January 11, 2016 @07:52PM (#51282951)

    I mean, by the time you've gotten your infrared reflector photonic crystal tungsten ribbon rectangular emitter Rube Goldberg thing perfected, it's bound to be a lot more expensive than current incandescent bulbs, and probably more expensive than LED bulbs. Plus, it is still working by getting a thin piece of metal hot enough to glow brightly. That inevitably means limited lifespan.

    Personally, I buy cheap LED bulbs when I see them on sale, and I haven't had one fail yet. Other than the older silicone-rubber-over-glass Cree bulb which I dropped. It still works fine, actually, but with electrically 'hot' bits exposed, I'm not running it.

    I don't know from spectrum, but I got a lot of pushback on installing CFLs. This has not been an issue with the LEDs I've gotten; they seem to have a good WAF (Wife Acceptance Factor) whatever their "spectrum" might be.

    The big problem with LEDs might turn out to be they just don't die. Once everyone has replaced every bulb with an LED, who's going to be buying bulbs?

    What I'm wanting to see is more fixtures that are built with LEDs, rather than assuming people are going to have to replace bulbs constantly.

  • by Trogre ( 513942 ) on Monday January 11, 2016 @08:20PM (#51283111) Homepage

    A similar method was reported here [slashdot.org] back in 2002.

    It would be good to have a light source that gives a full, even spectrum again.

    As others have commented here, I also wonder about the longevity.
    I believe that current incandescent bulbs fail mostly as a result of heat. These new bulbs, if they do run cooler would need to be designed with a completely different impedance model, since traditional incandescent bulbs run a delicate balance using heat and the resulting impedance to maintain some kind of equilibrium. This is why they most often fail immediately after being switched on - the bulb is cool (low resistance) so for a brief moment there is a large amount of current flowing through the filament before it heats up enough to reduce the current to a safer level. If that spike happens to coincide with a peak of the AC waveform then the filament, already weakened by many heating/cooling cycles, stands a good chance of burning out.

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