Technology

Piezoelectricity

Piezoelectricity is the electric charge thataccumulates in certain solid materials (such ascrystals, certain ceramics, andbiological matter such as bone, DNA and various proteins)[1] in response toapplied mechanical stress. The word piezoelectricity means electricityresulting from pressure. It is derived from the Greekpiezo or piezein(πιέζειν), which means to squeeze or press, and electric or electron(ήλεκτρον), which stands for amber, an ancient source of electric charge.[2]Piezoelectricity was discovered in 1880 by French physicistsJacques and PierreCurie.[3]

The piezoelectric effect is understood as the linear electromechanicalinteraction between the mechanical and the electrical state in crystallinematerials with no inversion symmetry.[4] The piezoelectric effect is areversible process in that materials exhibiting the direct piezoelectric effect(the internal generation of electrical charge resulting from an appliedmechanical force) also exhibit the reverse piezoelectric effect (the internalgeneration of a mechanical strain resulting from an applied electrical field).For example, lead zirconate titanate crystals will generate measurablepiezoelectricity when their static structure is deformed by about 0.1% of theoriginal dimension. Conversely, those same crystals will change about 0.1% oftheir static dimension when an external electric field is applied to thematerial. The inverse piezoelectric effect is used in production of ultrasonicsound waves.[5]  




Piezoelectricity is found in useful applications such as the production anddetection of sound, generation of high voltages, electronic frequencygeneration, microbalances, and ultrafine focusing of optical assemblies. It isalso the basis of a number of scientific instrumental techniques with atomicresolution, the scanning probe microscopies such as STM, AFM, MTA, SNOM, etc.,and everyday uses such as acting as the ignition source forcigarette lightersand push-start propane barbecues.