piezoelectric injector

A piezoelectric injector is a fuel injector built around piezoelectric ceramic or crystal elements that change shape almost instantly — in a fraction of a millisecond — when an electric current is applied. This rapid response lets the injector open and close several times within a single combustion cycle, enabling additional injection stages such as a pilot injection before the main event and a post injection afterward, which makes combustion smoother, quieter, and more efficient. Piezoelectric injectors are widely used in modern common rail diesel injection systems.