Applications where strongly-piezoelectric materials are used
include buzzers inside pagers and cell phones, shakers inside ultrasonic cleaners, spark generators
inside electronic igniters, and strain sensors inside pressure gages.
Piezoelectric materials also make inexpensive but fantastically accurate "clocks". For example, the element keeping track of time inside a quartz watch is literally a small piece of vibrating quartz. Its vibration period is stable to more than one part per million as a result of its piezoelectic properties.