Piezoelectric Piezoelectric MaterialsMaterials

MEEN 3344MEEN 3344Edward L. GaminoEdward L. Gamino

September 21, 2009September 21, 2009

TypesTypes Quartz- first commonly used crystalQuartz- first commonly used crystal Lead Zirconate PZT-most common Lead Zirconate PZT-most common

ceramic in use todayceramic in use today Rochelle saltRochelle salt Cane sugarCane sugar BoneBone

                                          

Piezoelectric EffectPiezoelectric Effect

The piezoelectric effect was discovered in 1880 by The piezoelectric effect was discovered in 1880 by brothers Jacques and Pierre Curie. They discovered brothers Jacques and Pierre Curie. They discovered that when a mechanical stress was applied on crystals that when a mechanical stress was applied on crystals (such as tourmaline, topaz, quartz, Rochelle salt and (such as tourmaline, topaz, quartz, Rochelle salt and cane sugar) electrical charges appeared, and the cane sugar) electrical charges appeared, and the voltage was proportional to the amount of stress. voltage was proportional to the amount of stress.

An everyday application example is a car's airbag An everyday application example is a car's airbag sensor. The material detects the intensity of the shock sensor. The material detects the intensity of the shock (impact) and sends an electrical signal which triggers (impact) and sends an electrical signal which triggers the airbag to deploy. the airbag to deploy.

How Piezoelectricity WorksHow Piezoelectricity Works

                               

If a compressive force (mechanical stress or stress) is applied to the hexagon along the Y axes direction, the configuration is distorted to bring two of the positive charges closer together at one end and the negative charges at the other.  This forms a dipole where one end of the structure is positive and the other negative. Voltage at a distance along the X axes will now be present.  This process is also reversible.                                                  

Example : In a relaxed state with no forces acting on the positive or negative charges, they are arranged at the vertices of a hexagon.  The positive and negative configuration of charges will cancel each other out and the potential Voltage, a distance along the x axes will be zero.

ApplicationsApplications Sonar-first practical applicationSonar-first practical application Vibration DampenersVibration Dampeners PhonographsPhonographs TransducersTransducers Airbag sensorAirbag sensor LightersLighters PrintersPrinters Cell PhonesCell Phones

ReferencesReferences Callister, William D, and David G. Rethwisch. Callister, William D, and David G. Rethwisch.

Fundamentals of Materials Science and Engineering. Fundamentals of Materials Science and Engineering. New York: Wiley, 2008.New York: Wiley, 2008.

Jaffe, Bernard, William Cook, Hans Jaffe. Piezoelectric Jaffe, Bernard, William Cook, Hans Jaffe. Piezoelectric Ceramics. New York: Gould, Ceramics. New York: Gould, 19711971

Buchacz, A. ”Piezoelectric layer modeling by equivalent Buchacz, A. ”Piezoelectric layer modeling by equivalent circuit and graph method.” Journal of Achievements in circuit and graph method.” Journal of Achievements in Materials and Manufacturing Engineering 20 (2007).Materials and Manufacturing Engineering 20 (2007).

Homepage. Piezoelectric Materials. Homepage. Piezoelectric Materials. http://www.piezomaterials.com/index.htmhttp://www.piezomaterials.com/index.htm

Homepage. Piezoelectricity. Homepage. Piezoelectricity.

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