Understanding How a Piezo Motor Works

By Jack Cashmere


Piezoelectricity is a transducer relationship between electrical energy and mechanical oscillation. The piezoelectric effect happens in certain materials that have got the capacity to produce electricity when exposed to mechanical stress. This material tension-twisting, distorting or compressing-has to be just enough to deform the crystal structure without fracturing it.

Piezo properties are interesting because they're reversible. This means that materials exhibiting the direct piezoelectric effect, or the generation of electricity when stress is applied, also exhibit the opposite piezo effect, the generation of mechanical stress when an outside electrical field is applied.

Piezoelectricity was detected in the 19th century by Pierre and Jacques Curie. During that time, they were only 21 and 24 years old. The Curie brothers recognized that quartz crystals triggered an electrical field when pressured along a primary axis. The term piezo is derived from the Greek; Piezein, meaning "to squeeze or press," and piezo, which means "push."

A piezo motor takes advantage of the piezoelectric effect, or the tension that causes a multilayered material, like Rochelle salt or topaz, to bend when charged with an electric current. A piezoelectric motor does not produce or require magnetic fields, and it's not affected by them. In that regard, the piezo motor performs more accurately than the traditional electric motor unit. It's compact, remarkably powerful, rapid and it has neither rotors nor gears.

I once saw a piezo motor that was the size of a sugar cube. It could maneuver many centimeters at one time and could carry as much as 1,000 times its own weight.

Piezo motors have been implemented in microchip production for a long time, so this isn't a new idea. Zirconate, lead and titanate powders are refined, morphed and polarized. To create polarization, electrical fields are applied to line up the piezo materials along a primary axis.

This system seems complex, but the piezo motor functions the same way that elements containing iron are magnetized. After electric energy is applied, the motor employs its poled ceramic design to generate motion by using periodic, sinusoidal electric fields.

The ceramic side is coupled with a precision platform, and the resulting driving force of the piezo motor creates stage movement. Depending on how the combining mechanism is put together, a piezo motor can move both linearly and in rotationally. The regular nature of the driving current generates unlimited travel and consistent movement.

The piezoelectric motor has been created in a variety of ways for many different uses. For example, the traveling-wave piezo motor is used for the auto-focus function in reflex cameras. Some motors are employed in camera sensor displacement technologies, yielding anti-shake features.

You can find the piezo motor in handheld goods, healthcare devices, the auto industry as well as in electronic home appliances. The piezoelectric motor has started to become more and more cost-effective, even for widespread employment.

Although the piezoelectric motor represents one unique use of the piezo phenomenon, a great deal of other uses exist. Currently, modern ceramics are mass-developed for a variety of uses-ultrasonic cleaners and underwater transducers, for example.




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