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Convert muscular energy to electricity

  1. Jun 10, 2012 #1
    Hi to all physicists

    How can convert muscular (mechanical) energy to electricity without using a generator?

    In fact I am looking for a way to convert muscular energy to electricity energy without use the generator.
  2. jcsd
  3. Jun 10, 2012 #2


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    You can't, technically. Anything that converts another form of energy to electricity is a generator.
    If you're referring to myoelectric signals, as are used in controlling prosthetic devices, that isn't conversion. It's merely detection of what is already electricity.
  4. Jun 10, 2012 #3
    thanks for answer.
    but let's make my question more clear, I want to convert muscular energy into electrical energy, with highest efficiently
    and i need a small device (generator) to this purpose. which don't have Rotating shaft and gears?

    are there the generator don't have Rotating shaft and gears?
  5. Jun 10, 2012 #4


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    Sure. The forever flashlight does what you describe.
  6. Jun 10, 2012 #5


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    I have one of those! My boss at my last place of employment gave it to my mother several years ago. It's weak, and takes a lot of pumping, but it's a lot better than being in the dark.
  7. Jun 11, 2012 #6


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    A piezoelectric crystal in the heel of each shoe can do this. Or just click your gas lighter a lot of times. Or comb the cat.
  8. Jun 11, 2012 #7
    in forever flashlight the magnet slides back and forth through the coil and generated a pulse of electricity in the coil, in fact the system is linear motion. well can do this motion system in Rotational motion (clockwise and counterclockwise motion together) without Neutralization of current?

    thanks but piezoelectric crystal don't have enough efficiency for convert to electric
  9. Jun 12, 2012 #8
    What have you got against rotation?
  10. Jun 15, 2012 #9


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    mafik66, You are not alone in trying to generate useful power from piezoelectric generators, both crystalline and flexible film types. Here is a selection of products where they are useful. The last reference is the report of research to generate and store electrical energy. The researchers report it is NOT practical. DARPA has paid for several projects for soldiers to recharge their batteries by walking, etc., all without practical success. If you discover how to do this using muscle power, more power to you.




    "The investigation shows that the power output from a single piezo-film was very low in the range of 0.2 W. Therefore, direct application of the piezo-film as a power source is not practical. It is unavoidable to use a storage device to collect the weak power output for future usage. Fortunately, the voltage outputs from a single piezo-film can produce a root-mean-squared voltage of 1.18 V which is high enough to store the generated electricity into a small nickel metal hydride battery."
    www.wwwsst.ums.edu.my/data/file/SqD1WjfN7sf2.pdf [Broken]
    Last edited by a moderator: May 6, 2017
  11. Sep 4, 2012 #10
    is it efficient for me to use a piezoelectric crystal to capture the energy from the footstep of walking people and store it,for later use(light up the street lights)
  12. Sep 4, 2012 #11


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    elric, Welcome to Physics Forums!

    Research into soldiers generating power while walking using piezpelectrics has been done. The amounts of power are small, but are usable for recharging radio batteries, for instance. See:

    US Army's Boot-Based Energy Harvester Lightens Soldier's Load

    http://www.designnews.com/author.asp?section_id=1365&dfpLayout=blog&dfpPParams=ht%5F13%2Cindustry%5Falt%2Cindustry%5Fgov%2Caid%5F235935&doc_id=235935&image_number=1 [Broken]

    As for the second part of your question: storage and use to light up street lights: battery technology is improving the energy density storage capacity, but only gradually. Street lights use LARGE amounts of power, so probably human footsteps during walking just wouldn't generate enough power to light up the streets.

    Last edited by a moderator: May 6, 2017
  13. Oct 30, 2012 #12
    perhaps you could also use linear generators (magnet sliding along a spool), you could attach them to the side of boots
  14. Nov 5, 2012 #13
    Muscle power performs my job.

    I get paid.

    I pay my power bill.
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