General application of piezoelectric ceramic materials

The application of PZT materials piezo ceramic covers many fields of everyday life in today's society,  people may be involved in the application of piezoelectric materials almost every day. Piezoelectric ceramics are used for ignition of cigarettes, gas stoves, water heaters, car engines, etc.; electronic watches, voice-activated doors, alarms, children's toys, telephones also uses piezoelectric resonators and buzzers. For the management of factory buildings and safe and confidential places, as well as for reconnaissance and crime detection, piezoelectric sensors are capable of verifying the handwriting and sound characteristics of each person shall be used; piezoelectric electrical filters and piezoelectric SAW filters shall be used for household electrical products such as television sets. Piezoelectric transformers, piezoelectric fans,piezoelectric microphones and piezoelectric speakers for recorders; piezoelectric motors are used for cameras and video recorders, etc. Piezoelectric devices are widely used not only in industrial and civilian products, but also in military applications. A large number of piezoelectric ceramic filters and piezoelectric SAW filters are required for radar, military communications and navigation equipment. Piezoelectric ceramic material can also be applied to the identification of structural defects, the control of flexible structural vibrations, and medical immunoassays, cochlear implants and so on.

Piezoelectric crystals sensors are a class of dielectrics with piezoelectric physical properties, and are made into conversion elements widely used in piezoelectric sensors. The piezoelectric effect is manifested by the fact that when some dielectrics are deformed by external forces in the certain direction, polarization occurs inside them, and positive and negative opposite charges appear on the two opposite surfaces of the dielectric. When the direction changes, the polarity of the charge also changes, and the amount of charge generated by the force is proportional to the magnitude of the external force. When the external force of piezo ceramic sensor is removed, it will return to be the uncharged state. This phenomenon is called on the positive piezoelectric effect; on the contrary, when an alternating electric field is applied in the polarization direction of the dielectric, these dielectrics also undergo mechanical deformation, and the electric field is removed. After that, the mechanical deformation of the dielectric disappears. This phenomenon is called on the inverse piezoelectric effect. The positive piezoelectric effect is the conversion of mechanical energy into electrical energy, and the inverse piezoelectric effect is the conversion of electrical energy into mechanical energy.