What’s piezoelectric sensor？

The piezoelectric sensor has the advantages of high frequency response bandwidth, high sensitivity, large signal to noise ratio, simple structure, reliable operation and light weight. It has been widely used in many technical fields such as engineering mechanics, biomedicine, petroleum exploration, sonic logging, and electroacoustics.

Positive piezoelectric effect (parallel piezoelectric effect): Some dielectrics, when they are forced along a certain direction to deform it, the internal polarization occurs, and at the same time, charge is generated on a certain surface thereof, when the external force is removed. After that, the phenomenon of unpowered state is restored again. When the direction of the force changes, the polarity of the charge also changes.

Inverse piezoelectric effect piezoelectric ceramic disc (electrostrictive effect): When an electric field is applied in the polarization direction of a dielectric, these dielectrics generate mechanical deformation or mechanical stress in a certain direction, and when the applied electric field is removed, these deformations or stresses also disappear.

The ideal shape of a natural-structured quartz crystal is a regular hexahedron. In crystallography, it can be represented by three mutually perpendicular axes, where Z-Z is called the optical axis; X-X axis is called the electric axis; and X-X axis is The Z-Z axis and the vertical Y-Y axis (perpendicular to the facet of the regular hexahedron) are called mechanical axes.

The piezoelectric effect of piezo ultrasonic transducer is generating a charge under the force of the X-X direction of the electric axis is generally referred to as a "longitudinal piezoelectric effect", and the piezoelectric effect of generating a charge under the force of the Y-Y direction of the mechanical axis is referred to as "transverse piezoelectric effect", the force acting along the Z-Z direction of the optical axis does not produce a piezoelectric effect.