GoKawiilStatic electricity is so commonplace that it can come across as simple. Rub a balloon against your head, and the transfer of charges will make your hair stand on end. Shuffle your feet on a carpet, and the charge imbalance you produce can shock an innocent passer-by.
Leading the charge to explain static electricity
So it might come as a surprise that static electricity — which arises from what researchers in the field call the triboelectric effect — has left scientists racking their brains for centuries. Some of the basics are clear. Materials transfer charges when they’re rubbed or otherwise come into contact with each other: one becomes more positively charged and the other more negatively charged. Opposite charges attract whereas identical charges repel, and ta-da, you have a primary-school science experiment.
But most everything else in this field remains baffling. Is it the electrons, ions or bits of material that transfer the charge? Why do some materials charge positively and others negatively? What happens when two samples of the same material come into contact? For instance, when “rubbing a balloon on a balloon”, says experimental physicist Scott Waitukaitis at the Institute of Science and Technology Austria in Klosterneuburg. A big part of the problem is that experiments tend to misbehave, with the same procedures producing different results.
Now, researchers are picking apart some of the puzzles that have long plagued the field. With sophisticated laboratory set-ups that carefully control for compounding factors, Waitukaitis and his team have found that the charging of some materials has a strange tendency to hinge on their past interactions1. This week in Nature2, Waitukaitis and his colleagues report that carbon-carrying surface molecules can have a role in guiding which way charge is exchanged.
The secrets of static electricity are finally being revealed
These discoveries “are the best work in a really long time” in the field, says Daniel Lacks, a chemical engineer who has studied triboelectricity at Case Western Reserve University in Cleveland, Ohio. Other teams are investigating how surface area and velocity during impact might govern charge transfer, and how the breaking of chemical bonds contributes.
The influx of research seems to be driven by a desire to scrutinize the fundamental physics at play, says Laurence Marks, a materials scientist at Northwestern University in Evanston, Illinois. A better understanding of the science of static electricity could lead to improved devices that use it to power remote sensors or wearable technologies without batteries3, for example. It could also help to prevent the electrical discharges that can cause industrial explosions.
It’s becoming increasingly clear that static electricity is far from a simple phenomenon that abides by one clear-cut set of rules, researchers say. Instead, each exchange of charges could be shaped by several factors that vary with the circumstances. Some of these factors are now known and others are still waiting to be uncovered.
Ancient observations
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