Piezoelectricity

 

The Piezoelectric Effect is the ability of certain crystals to generate an electric charge in response to applied mechanical stress. The word Piezoelectric is derived from the Greek piezein, which means to squeeze or press, and piezo, which is Greek for “push”.

Piezoelectricity Discovery

A related property known as pyroelectricity, the ability of certain mineral crystals to generate an electrical charge when heated, was known of as early as the 19th century, and was named by David Brewster in 1824. The first reference to the pyroelectric effect is in writings by Theophrastus in 314 BC, who noted that Tourmaline becomes charged when heated. Sir David Brewster gave the effect the name it has today in 1824. Both William Thomson in 1878 and Voight in 1897 helped develop a theory for the process behind pyroelectricity. Pierre Curie and his brother, Jacques Curie, studied pyroelectricity in the 1880's, leading to their discovery of some of the mechanisms behind piezoelectricity.

 

The first demostration of the piezoelectric effect was in 1880 by the Curie brothers using tinfoil, glue, wire, magnets, and a jeweler's saw. They combined their knowledge of pyroelectricity with their understanding of the underlying crystal structures that gave rise to pyroelectricity to predict crystal behavior. They showed that crystals of Tourmaline, Quartz, Topaz, cane sugar, and Rochelle salt (sodium potassium tartrate tetrahydrate) generate electrical polarization from mechanical stress. Quartz and Rochelle salt exhibited the most piezoelectricity.