Forgot your password?
typodupeerror
Canada Technology News Science

Google Science Fair Finalist Invents Peltier-Powered Flashlight 170

Posted by Soulskill
from the now-make-a-peltier-powered-bicycle-and-you've-got-an-investor dept.
GTRacer writes "Ann Makosinski, a Canadian student competing in Google's Science Fair, submitted a flashlight which uses temperature differentials to power its LEDs. Her long-time interest is alternative energy because, '[she's] really interested in harvesting surplus energy, energy that surrounds but we never really use.' Using Peltier tiles and custom circuitry, her design currently runs for 20 minutes or so and costs $26. A win at the September finals in Mountain View and/or outside investment could fund further development."
This discussion has been archived. No new comments can be posted.

Google Science Fair Finalist Invents Peltier-Powered Flashlight

Comments Filter:
  • by Anonymous Coward

    Will not work so great with a 2 degree delta T

  • FlashDark? (Score:5, Funny)

    by AdamThor (995520) on Tuesday July 02, 2013 @08:07PM (#44171635)

    So if you're hanging around the desert and the ambient temp is warmer than your hand, will it make things darker? That would be cool.

    • Re: (Score:2, Funny)

      by Anonymous Coward

      So if you're hanging around the desert and the ambient temp is warmer than your hand, will it make things darker? That would be cool.

      No, it's for when you're lost in the arctic and freezing to death. Some of your wasted body heat will let you see the wolves circling...

  • by Anonymous Coward

    Does she put it in the fridge before using it or something?
    Or does it use the difference in temperature between your hand and the flashlight.

    Also, since this is generating electricity from a temperature differential, rather than generating a temperature differential from electricity, wouldn't this be the Seebeck effect?

    • Re: (Score:3, Funny)

      by Anonymous Coward

      She's from Canada, so there's likely a pretty massive delta between the ambient air temperature and human body temperature. It, like elections, probably doesn't work in Florida.

      • Re: (Score:3, Interesting)

        by barc0001 (173002)

        She's from Victoria, BC. It was almost 90F in Victoria over the weekend. Which is apparently about what it is in Miami right now. It's not all a frozen wasteland up here ya know.

    • by Ungrounded Lightning (62228) on Tuesday July 02, 2013 @08:44PM (#44171867) Journal

      Does she put it in the fridge before using it or something? Or does it use the difference in temperature between your hand and the flashlight.

      The latter.

      If you RTFA you'll see she's using the aluminum flashlight body as a heat conductor and the "head" and other exposed portions of it as an air-cooled heatsink.

      She's stuck the handle of the light into an insulating plastic pipe, cut a hole in the pipe, and stuck the peltier cell in the hole, with the "cold" side in contact with the flashlight handle and the "warm" side in contact with the hand. (I expect the next step is to wrap an outer aluminum tube around it to conduct heat from the whole hand to the cell, rather than just heating it with a patch of palm directly contacting it.)

      Voltage boost converter between the peltier assembly and the LED (because the peltier cell she used was not stcked for the right voltage to drive the LED.) The LED shines as long as you hold it, if the air is cool enough. (She's used it for 20 minutes running.)

      Also, since this is generating electricity from a temperature differential, rather than generating a temperature differential from electricity, wouldn't this be the Seebeck effect?

      Yes. Seebeck discovered current generation from heat differential (with dissimilar metal wires and a compass needle), then Peltier discovered heat-pumping with current.

      But, like most rotating electric machinery (where the same device is a motor or generator depending on whether you power it or twist it), the same effect is a heat pump or heat engine (depengding on whether you apply a temperature difference and pull power or apply power and pump heat).

      The effect is now often called the "Peltier-Seebeck effect" in textbooks. The cells are typically called Peltier Cells because the efficient ones are manufactured mainly for heat-pumping, though they work just fine both ways.

  • Someone told me this girl will become a billionaire if she can figure out how to make a heat-based car engine out of Peltier tiles. I replied with a long sigh and this link: http://en.wikipedia.org/wiki/Stirling_engine [wikipedia.org] The Stirling engine was invented in 1816.
  • This reminds me of Quantum Paleontology...."throw the switch, energy crisis averted."

    http://www.youtube.com/watch?v=KLoOI5Laplo [youtube.com]

  • She'll go far (Score:5, Insightful)

    by Smallpond (221300) on Tuesday July 02, 2013 @08:22PM (#44171703) Homepage Journal

    Makosinski admitted there were points in the experiment when she thought it would never work, but said "You just kind of have to keep going.

    Way more important lesson than the circuit design.

  • by dbIII (701233) on Tuesday July 02, 2013 @08:26PM (#44171725)
    Being able to get light out of such a tiny current source as a thermocouple is amazing. Since it's just two dissimilar metals in electrical contact to provide the electricity there's plenty of scope to improve the design and get something mass produced for a lot less than $26.
    The summary may confuse people since they may be thinking of peltier cooling, which is providing electricity to create a temperature difference, but the same hardware produces electricity from a temperature difference (and is normally known as a thermocouple in that mode).
    • by _merlin (160982) on Tuesday July 02, 2013 @08:34PM (#44171791) Homepage Journal

      It's not thermocouples with dissimilar metals. It's Seebeck effect using semiconductor junctions. (Peltier effect is the use of voltage to generate a temperature differential, Seebeck effect is use of a temperature differential to generate voltage, but you can use the same devices for both.)

      • by dbIII (701233)
        Who modded this up? Merlin, I suggest you look up what a thermocouple is and you'll see the way it works is the Seebeck effect. There's no point throwing around words you do not understand in the face of a far simpler explanation that was written to try not to confuse readers such as yourself by adding a third term.
      • by dbIII (701233)
        Also the semiconductor junctions are a junction of dissimilar metals.
        • by _merlin (160982)

          They aren't dissimilar metals at all - they're semiconductor metalloids that are N- or P-doped, i.e. silicon or germanium with impurities added, just like the active devices in integrated circuits.

          • by dbIII (701233)
            Which gives the silicon different (as in not similar) electrical properties, just as with a type K thermocouple it uses the junction between two different nickel alloys.
    • by msauve (701917) on Tuesday July 02, 2013 @08:46PM (#44171889)
      The summary and article are incorrect. The Peltier effect is converting a voltage difference into a temperature difference. In this case, it is the Seebeck effect being used to convert a temperature difference into a voltage difference. So-called "Peltier devices" can work both ways, but aren't typically called thermocouples ("thermocouple" usually used for a device intended to convert temperature to voltage), even if they are in strictly technical terms.

      The Seebeck effect was discovered first, so referring to it as the Peltier effect should be considered inappropriate (if not insulting to Thomas Johann Seebeck).
      • by GTRacer (234395)
        I saw commentary about Peltier versus Seebeck before I wrote the summary. The CBC will have to explain their position. In any case, what I read, and it goes without saying that IANAEE, is that Peltier and Seebeck are reversible from a strictly technical point of view based on how the differential is handled. I think?

        I'm open to being educated in this regard, if you so feel the need.

        In any case, I thought it was an interesting article and I hope that, should she get funding, the issues with maximum output
        • by mattack2 (1165421)

          way cooler than the typical fair fare!

          Of course it's cooler... That's how it's being powered.

          (But seriously, won't this thing "feel cold" in your hand? Do you really want to hold onto a cold flashlight continuously?)

  • by evilviper (135110) on Tuesday July 02, 2013 @08:45PM (#44171869) Journal

    Her long-time interest is alternative energy because, '[she's] really interested in harvesting surplus energy, energy that surrounds but we never really use

    The thing her presentation is missing is any acknowledgment that she has actually learned something, and realizes now that her flashlight is a neat little science trick, but otherwise terribly impractical.

    It only works for a few minutes, as the flashlight heats up to match your body temperature, and wouldn't work at all where ambient temps are remotely similar to body temperature. She also got only a tiny amount of power and light out of it, which could be provided for weeks or months by a watch battery without the expensive peltier in the mix.

    Slightly more interesting than vinegar and water mixed together in a model volcano, but the real question is whether she learned something valuable in all of this.

    • by Xyrus (755017)

      I have to agree.

      It's fairly simple to use something like a Joule Thief circuit in conjuction with peltier tiles and an LED to make a low power flashlight, but it is fairly impractical. Even mass produced these would still cost more than a standard LED flashlight, and the standard flashlight will have higher light output and more life.

      It's a cool high school science experiment, but not really ground-breaking.

      • by Luyseyal (3154)

        They're probably thinking of the canonical "powerless village in Africa" scenario where any 2-bit technology will "save lives" and "expand freedom".

        -l

    • Ok, so you have a better design?
      • by evilviper (135110)

        Anything you can buy is better.

        Crank or squeeze flashlights do a fine job.

        Solar powered flashlights do a very good job, and are hassle-free.

        NiMH LSD batteries (AAA/AA/D/9V) are only about 3x the price of disposibles, hold a charge forever, work in any common flashlight, and can be recharged with the cheapest and simplest solar battery chargers, as well as conventional chargers.

        If you want a thermocouple design... Mount the peltier to a stove, and hook the leads to a battery charger.

    • Re: (Score:3, Funny)

      by Anonymous Coward

      wouldn't work at all where ambient temps are remotely similar to body temperature.

      She is Canadian. It wont be a problem.

      Slightly more interesting than vinegar and water mixed together in a model volcano

      Every third grader knows that vinegar and baking soda are required ingredients to make a model volcano. She may not have learned something, but at least you have.

    • by RKThoadan (89437) on Tuesday July 02, 2013 @09:23PM (#44172101)

      The last time I needed a flashlight I really only needed it for a few minutes to find candles and such. The time before that I was just looking for something in my trunk at night. 20 minutes is more than enough for either of those circumstances. The last time I needed a flashlight to last longer than 20 minutes was probably spelunking over a decade ago.

      In most cases ambient temp was decently lower than my body temp just because it's usually evening/night time when it's needed. I used to have one of the shake-style flashlights, but it seems to have vanished. You pretty much had to shake it constantly for it to work, which made actually looking for things with it quite difficult. In any case, having a flashlight around that I know will work regardless of battery quality is a good thing.

      In short: I would absolutely buy one of these.

      • by evilviper (135110) on Wednesday July 03, 2013 @01:03AM (#44173083) Journal

        The "shake" lights are a terrible design, almost as gimmicky as this one . You can go with solar powered lights, so the battery will be kept charged. Or you can go with crank-type flashlights, which will turn a minute of work into several minutes of light.

        Personally, I'm happy with batteries. Low self discharge NIMH batteries are extremely impressive. I have a single, seperate solar battery charger in the event of power outage or hiking, and can be used to power radios, phones, or anything else. And I've got the freedom to select whatever design of light I want, inexpensively, from pocket sized units I carry around, to room-illuminating lantern-replacements, to high intensity lights.

        • by jnowlan (618290)

          'shake' flashlights are great. No need to wonder if you have a charge, just shake the thing. Great for when you just need the occasional minute of light, like at the cottage when you need to find the outhouse in the middle of the night. Batteries are always dead when you need them most.

          I've used different ones and some are definitely better quality than others.

          • All shake flashlights are pretty horrible compared to old Russian squeezelights. [ebay.com]

            Just like with shakelights, quality varies, and some have batteries in them that will not last. But you can continuously use a good squeezelight for a half hour or more (depending on your hand strength - I can use mine for hours because I type a lot) and the light beam will stay focused right where you want it the whole time - which is impossible with any shakelight.

            Also, since shakelights have powerful neodymium magnets in th

      • The last time I needed a flashlight I really only needed it for a few minutes to find candles and such.

        Whoa, me too! The last time I needed a fleshlight it was only for a few minutes as well! Oh wait, wrong site.

    • by GTRacer (234395)
      I don't usually do this, but I'm feeling contrary this week. The linked article covered the fact she's been doing science fairs for years and for this one, tried some designs of her own before settling on an of-the-shelf piece. It's implied but not stated in the source that she's personally invested and not just going through motions.

      Also, what's the point of doing one with a battery? We *have* those already! Her idea would be great in a pinch if the longevity could be fixed. Which Google prize money or v
      • The longevity can't be "fixed", it depends exclusively on environment and for a given environment it won`t change, Google prize money or not. It is an interesting idea for a high school science project but it is not really a viable product.

        If you want to convert body energy into light there are dynamo based flashlights that are far more efficient to do this and do not lack this design hindrances.
        • I mean "lack these design hindrances".
        • by GTRacer (234395)
          You don't think there are possible efficiencies in the Peltier/Seebeck circuit? Or more thermally-conductive metals/materials that would help with moving heat around? Or options for storing current on board for use later?

          If this device was working at 100% efficiency, then yes, it's pretty much a dead end. But is it?
          • More efficiency would increases the current and allow for brighter or more leds, not more autonomy. More autonomy would require a LOT more efficiency, a battery and a charge circuit, at which point a dynamo or solar cells would be much better solutions as sources of energy to charge the battery. Even running at a much greater efficiency there isn't much energy to take from the system before the body and flashlight temperatures reach equilibrium and unlike dynamos the energy amount is highly dependent on the
    • by quax (19371)

      ".... where ambient temps are remotely similar to body temperature."

      She's from CANADA you insensitive klutz.

    • It only works for a few minutes, as the flashlight heats up to match your body temperature, and wouldn't work at all where ambient temps are remotely similar to body temperature. She also got only a tiny amount of power and light out of it, which could be provided for weeks or months by a watch battery without the expensive peltier in the mix.

      Slightly more interesting than vinegar and water mixed together in a model volcano, but the real question is whether she learned something valuable in all of this.

      Others already commented, but the fact is that a flashlight is rarely used for more than 15 minutes and temperatures in whole Europe and most of North America (especially Canada) are almost all the time and everywhere significantly below body temperature, especially when/where a flashlight is needed (e.g. at night or in a basement).

      I agree about batteries, but they have a very bad habit of running out of juice just when they are most needed. And it is difficult to look for a replacement battery in darkness

      • by evilviper (135110)

        a flashlight is rarely used for more than 15 minutes

        Perhaps, but is it in your hand the whole time? If I set it down next to me as I change my tire, this thing won't produce any light.

        This thing is zero-maintenance

        So is a solar flashlight, so is a wind-up flashlight, so is a plug-in rechargeable flashlight, etc.

        And in an emergency is not the time to mess around with a toy like this that gives out barely any light, because there's so little to be had from the temperature differential.

    • by nblender (741424)

      Yes. She's learned that she can engineer something cool as long as she has some tenacity.. She's a 15 year old.. This idea is not likely to change the world but what world changing technology did you come up with when you were 15? My son has been 'inventing' since he was 6... He's almost 12 now and his inventions are starting to become interesting and I can see a steady progression to useful. This is just a notable datapoint on her life trajectory...

      Her parents probably encouraged her and clearly she h

      • by evilviper (135110)

        She's learned that she can engineer something cool as long as she has some tenacity..

        Oh? Was this an engineering fair? And here I though it was a science fair....

    • So negative, you should brighten up a little.

      This is the first model and if there is enough interest this will spurn research into how to get around these limitations. Even if the problem isn't solved for this particular scenario, there are bound to be other scenarios where waste energy is still hotter than the ambient air. Think of a furnace for example.

      Part of the challenge of innovating is doing stuff despite being told it shouldn't work and finding a suitable application when it finally does work.

      • by evilviper (135110)

        This is the first model and if there is enough interest this will spurn research into how to get around these limitations.

        There has been interest in improving peltiers for many decades, and this flashlight will make no difference.

        And for thermal power in general, you can't exceed the Carnot limit, so a flashlight or other body-temperature powered device will never be practical.

        there are bound to be other scenarios where waste energy is still hotter than the ambient air. Think of a furnace for example.

        And to

  • The Matrix (Score:5, Funny)

    by NIK282000 (737852) on Tuesday July 02, 2013 @08:45PM (#44171873) Homepage Journal

    This is how it starts.

  • by hawguy (1600213) on Tuesday July 02, 2013 @09:04PM (#44171991)

    She said she's getting about 5mw of power from it, which sounds pretty decent from just a 5 degC temperature differential *and* using circuitry to increase the voltage. Should be quite visible in the dark, even enough to read from if held close to a book. At least until the aluminum heats up from her hand and the hole in the middle turns out to be inadequate to sink enough heat to maintain the temperature differential under most conditions (though she's in Canada, so maybe that's not such a problem there :-) ).

    In comparison typical 2000mAh alkaline AA cell can support 5mw for about 600 hours, but if you can't afford alkaline batteries (or are someplace where you don't have easy access to them), then this flashlight may be better than nothing. Though a crank-up generator flashlight might be brighter and more usable.

    It may not save the world, but it's a great science fair project.

    • by roc97007 (608802)

      I wonder if it would work better as a glove, with the heat source (your hand) completely enclosed, and more surface area (the outside surface area, not the interior of a tube) to be chilled by the air.

      • And, there, my friend, is the ultimate point of research and innovation...it has somebody thinking how to extend her work.

    • by mjwx (966435)

      In comparison typical 2000mAh alkaline AA cell can support 5mw for about 600 hours, but if you can't afford alkaline batteries (or are someplace where you don't have easy access to them), then this flashlight may be better than nothing. Though a crank-up generator flashlight might be brighter and more usable.

      It's not a question of affording AA batteries in some scenarios, it's a matter of getting them or being certain they'll work.

      Alkaline batteries have a shelf life. I once worked in a machine shop at a mine. As one of the lowest level peons one of my glorious tasks was testing all the battery powered devices in the shop and once every 2 months, replacing all the replaceable batteries in all the battery powered devices (regardless of if they worked) as if one torch (flashlight for the Americans) didn't work

    • Ever have a flashlight in a car? not only do the batteries wear out but in the winter they don't work either! This thing will work well in the cold and for short periods at other times... and not at all in the summer.

      • by hawguy (1600213)

        Ever have a flashlight in a car? not only do the batteries wear out but in the winter they don't work either! This thing will work well in the cold and for short periods at other times... and not at all in the summer.

        I think even your "dead" batteries are going to put out more light than this 5mw light. I keep a 2 AA LED light in the car with lithium batteries (and an extra set of batteries) -- lithium's last much longer than alkalines, have a 10 year shelf life and work fine even in termperatures well below zero. That's in addition to the 3D cell Maglite in the trunk, which has never failed me even though I only rotate the batteries out every year or two.

        • I have a hand crank generator flashlight in my car. It had a battery but I replaced it with a super capacitor... which cost more than the cheapo flashlight.

          Oh, its about 4V. Yeah, I put some contacts to the outside; I can power a cell phone, not sure how long - i didn't test it.

  • I'm assuming it works until the temperature differential equals out to something that the peltier tiles can't use, then it has to cool off. Immediate thought was that putting it in the fridge (or better yet freezer) for a few minutes would cool down the tube and provide for an even larger temperature differential during use, until the temperature again equals out.

    So, for continuous use, the obvious solution is to pack the hollow tube with a miniature refrigeration unit, run on batteries.

    Waaaait a minute...

  • Get OFF my Lawn! (Score:5, Interesting)

    by Anonymous Coward on Tuesday July 02, 2013 @09:55PM (#44172271)

    I can not believe the comments I am reading here. There are initiatives all over the world to get more females into STEM stuff and everyone here seems to quibble about the technical details! She's a teenager. I first learned about the Peltier effect in my 4th year at University, yes that was 40 years ago. My kids didn't learn about it in their High Schools either. So much for the U.S. education system. Give the kid a break!

  • by Dahamma (304068) on Tuesday July 02, 2013 @11:03PM (#44172571)

    She just invented a new flashlight, and wants to use "energy that surrounds but we never really use."

    Like, the energy that surrounds us and penetrates us, and binds the galaxy together? Her "long time interest" is clearly building a light saber.

  • Shouldn't it work as long as the ambient temperature is lower than body temperature?

    Or does the battery she put in it after not getting it working in time only last that long?

  • about 8 years ago on this site. However, I was suggesting it for buoys, as well as road signs. What peltier counts on, is temp differentials. So, if a post is 3' in the ground, then the temp is normally different than air. By simply designing a system to carry heat up and down, then it is possible to get the difference. The buoy is even easier. The air is rarely the same temp as water. As such, it would be possible to charge a battery or even an ultra-cap to provide power during the x-over.
  • A bit of googling turns up this cheap IC [reuk.co.uk] that would do the job (it's specifically made for running USB or LED devices off of low-voltage power sources).

    But kudos to her for making the thing work & winning the prize. Anything that encourages kids to get into STEM is a good thing.

  • I always wondered why this effect couldn't be used as a power source on tidally-locked bodies such as the moon. Permanent shadow keeps the cold side cold and permanent sun keeps the hot side hot.

    Hmm. Maybe it isn't being proposed due to the iron-clad McDLT patent.
  • by QilessQi (2044624) on Wednesday July 03, 2013 @09:34AM (#44175603)

    Vampires and zombies are already at room temperature; this is USELESS for them! What about THEIR flashlight needs?

  • Flashlights are neat but there's superior technology. Charging from physically spinning a tiny alternator in current models by squeezing a trigger in the handle is far more effective and energy can be stored in gigantic capacitors instead of a battery.

    What I'd like to see is a peltier tile suit that effectively cools the user. An air conditioning suit that operates based on electricity from a heat differential would be amazing. The only catch is, human skin temperature is like 82 Fahrenheit or something
  • What happens after 20 minutes? If this setup really generates enough energy, shouldn't it last indefinitely?

Never put off till run-time what you can do at compile-time. -- D. Gries

Working...