Types of piezoelectric ceramics
Publish Time: 2019-07-02 Origin: Site
Barium titanate piezoelectric ceramics
2.Lead zirconate titanate piezoelectric ceramics (PZT)
Lead-free piezoelectric ceramics and their transducer shapes
Polytetrafluoroethylene (PVF2) is a polymer film with strong piezoelectric effect. The synthetic polymer film has no piezoelectric effect in terms of its symmetry, but they have a "planar sawtooth" structure. A dipole that can't be offset. After stretching and stretching, the molecular chain axes can be regularly arranged, and spontaneously polarized dipoles are generated in a direction perpendicular to the molecular axis. When a DC high voltage electric field is polarized in the film thickness direction, it can be a polymer film having piezoelectric properties. This film is flexible and easily fabricated into a large-area piezoelectric ultrasonic tranducer. This type of component is resistant to impact, it is not easily broken, it has good stability, and has a wide frequency band. In order to improve its piezoelectric properties, it is also possible to incorporate a piezoelectric ceramic powder to form a hybrid composite material (PVF2-PZT).
(4) Piezoelectric semiconductor materials
Such as ZnO, CdS, ZnO, CdTe, such a force sensitive device has the advantages of high sensitivity and short response time. In addition, ZnO is used as the piezoelectric material of the surface acoustic wave oscillator, and parameters such as force and temperature can be measured.
Measuring circuit of piezoelectric sensor
The piezoelectric sensor can be equivalent to a voltage source as shown in (a) or equivalent to a charge source, as shown in Figure (b).
Voltage amplifier
The PZT material piezoelectric plates piezoelectric sensor itself has a high internal impedance and a small output energy, so its measurement circuit usually needs to be connected to a high input impedance preamplifier.
1 voltage amplifier (impedance converter)
2 charge amplifier, charge amplifier is an amplifier whose output voltage is proportional to the amount of input charge.