Piezoelectrics and Multifunctional Composites

PerovsHtes and Related Mixed Oxides Concepts and Applications, First Edition. 

Edited by Pascal Granger, Vasile I. Parvulescu, Serge Kaliaguine, and Wilfrid Prellier. 

Although the major breakthrough of piezoelectric materials research happened for underwater detection, today piezoelectric materials span a large spectrum of applications, starting from simple applications such as timers and speakers to a wide range of healthcare and biomedical applications [2]. 

Piezoelectric phenomena possess an essential criterion for their existence in a given crystal. Among the 21 noncentrosymmetric point groups, crystal systems possessing the 20 noncentrosynunetric point groups alone could exhibit piezoelectricity [1]. The conventional or m other words, well-known material that exhibits piezoelectric behavior is quartz. A quartz crystal when cut in a specific direction exhibits a large piezoelectric response. However, the need for high- 

Flgure 10.1 Schematic diagrams detailing (a) the direct piezoelectric effect for compression and tensile stress and (b) the inverse piezoelectric effect with either tension or compression suffered by the material on subjecting to an external electric field. 

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There are many other multifunctional materials being created, for example, piezoelectric-piezomagnetic composite, magnetoelectric-piezoelectric composite, etc. They can respond to several different types of external fields and perform multiple functions. 

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