(1)The first practical application for piezoelectric devices was sonar, first developed during worldwar1. Piezoelectric materials are as a source of ultrasonic waves. At sea, they may be used to measure depth, the distance to shore, the position of icebergs, sub marines and the line.
(2) Piezoelectric devices found homes in any fields. Ceramic phonographs cartridges simplified player design, were inexpensive and precise, and made record players cheaper to maintain and easier to build.
(3) Probably the best known application is the electric cigarette lighter; pressing the button causes a spring-loaded hammer to hit a piezoelectric crystal, and the high voltage generated ignites the gas as the current jumps over a minute spark gap. The portable sparkers utilize to light gas grills or stones work the small way.
(4) It is used to detect sound, For example, piezoelectric microphones (sound waves bend the piezoelectric materials, generating a changing voltage) and piezoelectric pickups for electrically amplified guitars.