Piezoelectric actuators represent an important new group of actuators for active control of mechanical systems.

Piezoelectric actuators is used to convert electrical energy into mechanical movement, for precise positioning to nanometric levels, to produce ultrasonic energy and sonar signals, and for the conversion of pressure and vibration into electrical energy.

Piezoelectric actuators can also be manufactured in a variety of configurations and fabrication techniques

Piezoelectric actuators are also used to control hydraulic valves, act as small-volume pumps or special-purpose motors, and in other applications.

Operating principle:

Certain crystalline minerals: when subjected to a mechanical force, the crystals became electrically polarized. These behaviors were called the piezoelectric effect

Types of actuators:

The three basic types of piezoelectric actuators are stacks, linear motors, and benders.

Piezoelectric stack actuators

The linear movement produced by the piezoelectric effect has been used to make a stack actuator, which is a multilayer construction: each stack is composed of several piezoelectric layers

The required dimensions of the stack can be easily determined from the requirements of the application in question.

Linear motors

Since the voltage of the piezoelectric ceramic is relatively small, displacement amplifiers or hybrid structures are needed. There are many amplification techniques, such as levers and hydraulic systems, and piezoelectric motors.

The output force of the lever system is significantly less than the force of the actuator. Hydraulic systems generally use a piston for amplification.

This kind of piezohydraulic motor uses a linear piezoelectric actuator to control the liquid input to the fluid chamber which drives the bellows.