A Piezoelectric sensor is used to measure the changes in parameters like pressure, temperature, acceleration, and force, by converting them into the electrical charge. This sensor works on the principle of the piezoelectric effect. this sensor most suitable for security systems/ home automation system.
The effect in which mechanical energy is converted to an electrical form with applied pressure is called the piezoelectric effect. When a pressure is applied to a polarized crystal, the mechanical deformation created results in an electric charge.
Conversely, when a voltage is applied across the piezoelectric crystal, then the pressure will be possed on the atoms of crystal creating deformation.