Piezoelektromos

Piezoelektromos (literally "piezoelectric" in several languages) describes the property of certain materials to generate an electric charge in response to applied mechanical stress and, conversely, to deform when an electric field is applied. The effect arises from noncentrosymmetric crystal structures in which mechanical deformation shifts charge centers, producing a macroscopic polarization; the reverse (converse) effect follows from the same coupling between electrical and mechanical states.

The phenomenon was first observed in 1880 by Pierre and Jacques Curie and later formalized in modern electromechanical descriptions. Quantitatively it is characterized by material constants such as the piezoelectric coefficients (dij) and electromechanical coupling factors, which indicate the strength of conversion between mechanical and electrical energy.

Common piezoelectric materials include natural crystals like quartz and tourmaline, certain ceramics such as lead zirconate titanate (PZT), and polymers like polyvinylidene fluoride (PVDF). Each material class offers trade-offs among sensitivity, stiffness, temperature stability, and manufacturability.

Applications are widespread: sensors and accelerometers, actuators and precision positioning devices, ultrasonic transducers for medical imaging and sonar, frequency control elements in electronics, piezoelectric ignition systems, and small-scale energy harvesting. Limitations include temperature-dependent behavior, potential depoling, limited strain range, mechanical brittleness (in ceramics), and nonlinearity or hysteresis under large fields.

Piezoelectric technology continues to evolve with advances in material science, thin-film processing, and microelectromechanical systems (MEMS), expanding its use in consumer, industrial, and biomedical fields.