In 1960s, I listened to Gramophone machine with wonder, how it
worked, as its arm danced on a grooved disc that rotated round and round! When
the operator of this machine (player) lifted up its arm in changing the disc, I
noted a needle under it. I had been wondering about it
till I studied Physics at college. Yes, that needle (stylus) produced
electrical signals as it went up and down the grooves of the disc, (called as
record). It did it through a crystal mounted inside the arm's head (called as
pickup). This
stylus and the pickup did the whole magic in the gramophone record player -
producing Piezoelectricity!
A striking force or pressure on a material such as a quartz
crystal, can produce this piezoelectricity. This electricity was found out by
French Physicists, Pierre Curie and Jacques
Curie in 1880. This piezoelectricity is also used in Inkjet
printing, in SONAR and Radio Telephony. Earlier, I knew well about
some devices that produced sparks - cigarette lighter and the gas stove
lighter. Now, I know that they use this piezo effect in them! Do you know that
piezo effect is also used in watches and radio wave transmission?
The reverse of this piezo
effect has been also discovered to work for us! It produces Ultra Sound waves when
an electric curent is applied on to a crystal!
I am going on learning and
learning about new uses of piezo effect: it is used in cars for echolocation of
objects!
So, it is a wonder-full Piezoelectricity that is also exhibited by cane sugar crystals,
ceramics and even by our bones!
