Piezoelectric Actuator – Working & Types

It is a transducer that uses the piezo-electric effect to develop a voltage and use that voltage(electric energy) for the movement of the machine.

To know this machine more accurately let’s focus on the Pre-requisites

• Piezoelectric effect- this is the phenomenon where piezoelectric materials develop a potential difference when external physical energy is applied.

• Piezoelectric material- these are a special type of materials that get deformed and polarised when physical energy(like force and pressure) is applied to the material.

• Actuator- this is the part of a machine that is responsible for motion and control of movements when some control input signal is provided to it. in simple words, an actuator can be termed a Mover.

Now we can conclude in simple words that
PIEZOELECTRIC ACTUATOR is a machine that uses the polarisation of piezoelectric materials to develop a voltage and convert this electric voltage into mechanical movements.

Working Principle of Piezoelectric Actuators

They work on the principle of polarisation of piezoelectric materials. Certain crystalline minerals, when subjected to a mechanical force, the crystals became electrically polarized. These behaviors were called the piezoelectric effect.

The Basic Types of Piezoelectric Actuators

• A Piezo stack actuator is used to provide a low stroke through a high blocking energy.
• The Stripe Actuator is used to generate a large mechanical deflection reasonably in response to an electrical signal.
• Longitudinal actuators also known as piezo stacks use the piezoelectric effect for generating linear displacements.
• Piezo stacks are formed by coating several piezo elements on top of each other. Each element’s expansion effect will generate a useful force & movement.
• Shear actuators are related to longitudinal actuators because they have multiple piezo element layers but they vary in how the voltage is applied and the type of motion formed.
• Tube actuators include radial polarization & also use the transverse piezoelectric effect to make displacement.
• Flat actuators including two piezo elements can generate contracting motion once both elements operate mutually.

Applications of Piezoelectric Actuators

Piezo actuators help in precise knitting machinery, braille machines, industrial, automotive, medical, aviation, aerospace, and consumer electronics applications.