Everyone’s had that moment where they walk
across their carpet and reach for a door handle,
only to be greeted by an irritating shock.
This phenomenon is known as static electricity,
and a more drastic example can be seen when
lightning occurs.
Although chemists and physicists are unsure
of how exactly static electricity works, many
theories have sprouted as the scientific importance
of static electricity and its implications
continue to grow.
Static electricity is also known as triboelectricity,
or “rubbing amber”, due to Thaïes of
Miletus discovering an electric charge occurring
after rubbing amber with wool.
However, we know today that static electricity
does not only occur through frictional contact.
Just touching is sufficient for static electricity
to be initiated, and for static electricity
to occur, there needs to be an imbalance of
charge in a material that remains until it
can be balanced.
So what happens when you walk across a carpet
that gives you that electric shock when metal
is touched?
When you walk across a surface, you’re causing
a transfer of electrons to occur, since contact
between you and the floor initiates a chemical
reaction that allows the more electronegative
material to take electrons.
You can magnify the extent of the transfer
of electrons by wearing sock material that
tends to give up more electrons, such as wool.
Triboelectric series charts show materials
that tend to give up more electrons on top
and materials that tend to take electrons
on the bottom.
Once you give up some electrons, which have
a negative charge, to the floor material,
you’re positively charged.
As soon as you touch metal, which readily
gives up electrons, electrons flood through
skin contact to balance out the positive charged
atoms and you receive an electric spark.
This cannot happen when you’re wearing polyester
or rubber materials on your feet, since these
materials tend to take electrons through floor
contact and will not need to take any more
from touched metal.
Additionally, the loss of electrons causes
hair to stand, due to repulsion between the
hair strands from the increase in positivity;
this is similar to the two positive sides
of a magnet repelling.
You can even take a balloon, rub it on your
hair so it gains electrons, and temporarily
stick it to a wall as electrons attempt to
cross over to the wall and, in doing so, pin
the balloon.
Static electricity also occurs between the
ground and clouds during lightning, where
particles touching within clouds generate
static electricity and the temperature at
the point of electron transfer, or a thunder
bolt, can reach over 50,000 degrees F.
Static electricity also has many applications,
such as in toner printers.
In toner printers, a small wheel applies a
negative charge to a larger wheel.
The larger wheel is then exposed to a light
that neutralizes the charge in any blank areas
of the picture.
After it has passed through the light, it
is exposed to the ink toner, which is made
with a positive charge that allows the ink
to stick to all negatively charged areas.
Finally, the wheel presses the ink to a paper
below.
The demand for higher quality printers sparked
research in static electricity, no pun intended,
and static electricity will continue to be
studied as technology continues to advance.
