We will discuss here, piezoelectric effect and its cause
In the year of 1880 by P.R. Curie and Jack Curie had discovered it
They found that, when a mechanical stress is applied on crystal of certain materials
electrical potential appears across the materials. They also found that this electric potential is proportional to the applied stress
This is known as piezoelectric effect. In 1881, Gabriel Lippmann found that the converse of this effect can also be possible
Means when these crystals are applied with external electric field, there is a mechanical strain produced in the crystals
This is called inverse piezoelectric effect. The word piezo comes from the Greek word piezane, which means press or squeeze
The piezoelectric effect is basically initiated from electric dipoles within these materials
If there is any charge imbalance in the molecule, the molecule will have dipole moment
These dipoles tend to have the same direction when next to each other
and, they all together form regions referred as domains. As most of the dipoles are oriented in same direction in a domain
each domain will have a resultant dipolar characteristic. This is called polarity
Although, each domain has its own dipole moment, but, as a whole, a piece of crystal is non-polarized
This is because domains are randomly oriented in a crystal. For example, a crystal is a solid
It is a solid, but it has a crystal. It is a solid, but it has a crystal
It is a solid, but it has a crystal. But, when a strong electric field is applied across the piece of crystal
it is a solid. It is a solid, but it has a crystal
It is a solid, but it has a crystal. It is a solid, but it has a crystal
It is a solid, but it has a crystal. Not all, but many of the domains orient themselves in the direction of applied field
Due to change in orientation of uneven domains, there will be a mechanical stress in crystal
This is inverse piezoelectric effect. Due to change in orientation of uneven domains, there will be a mechanical stress in crystal
This is inverse piezoelectric effect. On the other hand when a mechanical stress is externally applied to pizza crystal
the crystalline structure is disturbed. The random orientation of the polarized domains is changed due to this force
As the orientations of dipole domains are no more entirely randomized, there will be an uneven charge distribution between two faces of the crystal piece
As a result there will be an electrical potential developed across then crystal
This is piezoelectric effect. If the applied mechanical stress is increased, the change in orientation is more and, hence, more electricity is produced
Hope, you got the idea. Thank you