Directpiezoelektrinen

Directpiezoelektrinen refers to the direct piezoelectric effect, the generation of electric charge or a measurable voltage in a piezoelectric material when mechanical stress or strain is applied. It is one half of the piezoelectric phenomenon, complementary to the converse effect where electrical stimulation induces mechanical deformation.

In crystalline materials lacking inversion symmetry, such as quartz, lead zirconate titanate (PZT), barium titanate, and polymeric PVDF, applied stress displaces charge centers and produces polarization. The magnitude of the electrical response is described by piezoelectric coefficients (typically denoted d_ij or g_ij) and depends on material, crystal orientation, and the mode of loading (compression, tension, shear). The generated charge or voltage is proportional to the applied stress or strain, and dynamic loading yields alternating voltages suitable for sensing or energy harvesting.

Applications include sensors and transducers: pressure sensors, microphones, accelerometers, and vibration energy harvesters. The direct effect enables passive sensing without an external power source and is fundamental in many compact devices. Material choices, temperature stability, and frequency response influence performance; high coupling coefficients are sought in ceramics like PZT while quartz offers excellent temperature stability.

History: The effect was discovered in 1880 by Jacques and Pierre Curie. Since then, piezoelectric materials have been engineered to enhance direct response for various electrical and sensing applications.