The New Old Wonders of Electrodes
Unless you are paid attention during science class or are
mainstay of science fairs, the term electrode will seem fairly
faraway to you. Some people even think that electrodes belong
only in science fiction as some sort of name for a weapon or an
engine.
But in reality, electrodes are an everyday reality. It is so
common that when you hold anything with a battery, you are in
effect holding electrodes too.
The term electrode was coined by the great English scientist
Michael Faraday. Faraday conducted early experiments on
electricity and conductivity. His discoveries opened the path
for the study of this branch of science.
Faraday called the positively charged electrode the anode and
the negatively charged electrode the cathode.
Electrodes are components in an electrical circuitry that
connects that circuitry to a conducting material. That material
could be liquid chemical, gas or any other conductive medium.
You will find electrodes in the most common electronic devices -
batteries, television, and even lamps.
Batteries have carbon anodes and zinc cathodes. These electrodes
connect to a chemical solution that produces electricity.
Televisions, radios and radars make use of electron tubes.
Electron tubes have electrodes within a glass tube that usually
contains mercury gas. These tubes are used to manipulate
electric current and electric signals.
In televisions, electrodes are present in the CRT, or cathode
ray tube. CRT's have a cathode that is heated to release
electrons.
An electron gun shoots these electrons into phosphor dots that
line the television screen. These dots glow as they come in
contact with the electrons therefore creating an image.
Electrodes prove to be very useful in medical applications.
Diathermy, for example, makes use of electrodes. Diathermy is
the generation of heat in the tissues of a body through the use
of electrode that conduct electrical currents to the skin.
This treatment is used to treat pain due to arthritis. Diathermy
is also used in surgery to cut tissues, coagulate, or kill cells
without inducing much bleeding.
Pacemakers also make use of electrodes. These electrodes are
connected to heart muscles to deliver electrical pulses when the
heart rate falls below a specified value. This forces the heart
muscles to contract and maintain the proper heart rate.
EEGs or Electroencephalograms, and EKGs or Electrocardiograms
make use of electrodes connected to a patient's body to monitor
their respective vital signs.
EEGs record a patient's brain activity. It represents it using
wave patterns on a roll of paper. In EEGs, the electrodes are
connected to skin over the skull. The information it records is
used to diagnose neurological disorders and determine whether a
person is already brain dead.
EKGs on the other hand have electrodes that are attached to
various parts of the body. It records the heart activity and is
instrumental in diagnosing heart ailments.
Electrodes even find their place in the welding industry. Arc
welding involves the use of electrodes to generate intense heat
to weld metals together. This type of welding is very effective
due to the high concentration of heat generated between the
electrodes of the welding machines.
In every industry, there is a use for electrodes. It is one of
the earliest yet most used inventions in the history of mankind.
Man is forever looking for way to take advantage of it, and will
continue to do so for a long time to come.