Study: Conventional Understanding of Static Electricity Is Wrong

By Joseph Castro | June 29, 2011 9:51 am

What’s the News: In high school physics classes, students are often taught that static electricity develops when electrons detach from the surface of one object and jump to another, causing a difference in charge. Since opposite charges attract, the two objects are drawn to one another (like your hair to a balloon). But new research published in the journal Science shows that static electricity is caused by more than just the exchange of individual electrons, and instead involves the transfer of bigger (yet still tiny) clumps of material.

How the Heck:

  • Scientists conventionally believed that static electricity required friction between two different non-metals, which would tug at their electrons with different amounts of force. But last year, a group of researchers at Northwestern University found that two sheets of the same polymer, like Teflon, can generate static electricity, also called contact electrification (pdf). After the discovery, some of the researchers, including chemist Bartosz Grzybowski, wanted to understand how it all worked.
  • Grzybowski and his team created static electricity between several materials and then scanned the charged surfaces with a Kelvin probe force microscope. Rather than seeing the expected uniform distribution of charge, the researchers noticed that the surfaces were actually patchworks of positive and negative regions just tens of nanometers across. The positively and negatively charged pockets were nearly equal in total area, but that tiny difference was enough to generate an overall static charge.
  • Using a couple of spectroscopy techniques, the team sought to learn how the charged mosaics emerged. The tests showed that when the surfaces of the materials rubbed together, nano-sized pieces of charged material transferred from one surface to the other. “It’s not the inherent properties of two polymers that matter,” Grzybowski told ScienceNews. “It’s because of the material transfer that you develop charge.”

What’s the Context:

  • The mathematician Thales of Miletus is often credited as the discoverer of static electricity. Around 600 B.C., the story goes, Thales noticed that amber attracted feathers and other light objects after being rubbed with fur. He believed that the rubbing rendered the amber magnetic.
  • We currently use static electricity in several modern technologies, such as air filters and photocopiers.
  • Peter Halliwell, a chemist with the University of Sydney, believes that the new understanding of static electricity will be important in the long run. “It will allow for more sophisticated applications,” he told ABC.

Not So Fast:

  • Daniel Lacks, a chemical engineer at Case Western Reserve University in Cleveland, agrees that material is being transferred during static electricity, but believes that the new research doesn’t completely rule out the old explanation for the phenomena. “We don’t know yet whether that’s the thing that dominates the charging,” he told ScienceNews. “It could work in combination with other things.”

The Future Holds: The researchers have yet to work out a complete picture of what happens during static electricity. In addition to material transfer, they suspect the phenomenon involves chemical reactions and the breaking and forming of chemical bonds on opposite surfaces.

(via Wired)

Image: Flickr/avhell

CATEGORIZED UNDER: Physics & Math
  • Chris

    Shocking!

  • Georg

    No,
    this is shocking only if You take such things from High school textbooks
    as “Conventional Understanding”.
    There are more nonsense things in those textbooks. Firsthand the
    misleading word “static” electricity.
    Georg

  • Jay Fox

    Just where and how does relative humidity play in all of this?

    “Conventional Understanding” holds that static electricity is reduced when humidity is relatively high. How and why does that work?

  • Tom K

    Huh?? Friction?? That’s certainly not conventional wisdom. I’ve taught physics at the high school level for 11 years, and have never taught that friction causes “static” electricity. Contact and separation. Friction merely increases the total amount of contact and separation that occur. If friction were required, physicists would be still scratching their heads, wondering how van de graaff generators work. As far as the exchange of material other than electrons, how many tens or hundreds of thousands of high school physics students have experimented with “static” electricity by putting two pieces of scotch tape together, then rapidly separating them? That’s one of the most basic activities to determine that there are two types of charge. Certainly, no one really thought that the only thing exchanged was electrons, did they??

  • :)

    Wonder if it is too late to get a grade change on one of my test from last term.

  • Tom Hanna

    What if we have more than one type of static electricity? Like amps and volts, change the amount or percentage and we will change the length and width of the arc, but it is still electricity!

  • soupysales

    What if someone didn’t understand irony? :)

  • http://discovermagazine.com Iain

    If it’s ironic, it won’t be static,it’s ferric.

  • Gilbert Sambolin

    want to light up the room? just shut the lights, take of your sneakers, and quickly pull off your white socks that are made of polyester. It seems that every single person that wears this type of
    socks as you walk you are creating a high amount of static electricity. Is this good or bad? Well
    to begin with the human body is actually a walking electric producer through every single nerve
    in the body and that is direct current. No one has yet tested the consequences of pains and ackes
    of the muscles, however I think that some of the extreme head ackes on humans are caused by too
    much static electricity generated by just walking, running and by the sunlight just shinning on the
    static producing clothing we wear.

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