The term “piezoelectric effect” refers to a material’s capacity to produce an electric charge in reaction to mechanical stress. The Greek words piezein, which means to squeeze or press, and piezo, which means “push,” are piezoelectric sources.
Being reversible is one of the special qualities of the piezoelectric effect; materials that show the direct piezoelectric effect—which is the production of electricity when stress is applied—also show the converse piezoelectric effect.
An external electrical field is produced when mechanical stress is applied to a piezoelectric material, causing the material’s positive and negative charge centers to move. The piezoelectric material is stretched or compressed when an external electrical field is reversed.
In various applications, such as sound generation and detection, high voltage generation, electronic frequency generation, microbalances, and ultra-fine focusing of optical assemblies, the piezoelectric effect is highly helpful. Additionally, it serves as the foundation for several atomic-resolution scientific instrumental techniques, including scanning probe microscopes (STM, AFM, etc.). More commonplace uses for the piezoelectric effect include cigarette lighters, where it serves as the ignition source.
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The History of the Piezoelectric Effect
The brothers Pierre and Jacques Curie were the ones who first observed the direct piezoelectric effect in 1880. The Curie brothers used crystals of tourmaline, quartz, topaz, cane sugar, and Rochelle salt to show the first piezoelectric effect. They did this by fusing their knowledge of pyroelectricity with their comprehension of crystal shapes and behavior. At the time of their first demonstration, the materials with the highest piezoelectricity capacity were quartz and Rochelle salt.
For the next few decades, as additional research was done to fully explore the enormous potential of the piezoelectric effect, piezoelectricity remained a topic of experimentation in the laboratory. The sonar device was the first piezoelectric device to be used in a practical setting, and it was introduced with the outbreak of World War I. The first application of piezoelectricity in sonar sparked a huge interest in piezoelectric devices among developers worldwide. Novel piezoelectric materials and novel uses for those materials were investigated and developed throughout the ensuing several decades.
A novel family of artificial materials known as ferroelectrics was discovered by research teams in the US, Russia, and Japan during World War II. These materials had piezoelectric constants that were far higher than those of naturally occurring piezoelectric materials. Even though quartz crystals were the first piezoelectric material to be utilized commercially and are still employed in sonar detecting applications, scientists continued to look for other materials with superior performance. Barium titanate and lead zirconate titanate, two materials with highly specialized characteristics appropriate for specific applications, were developed as a result of this intensive research.
Piezoelectric Materials
Numerous materials, both artificial and natural, display a variety of piezoelectric properties. Berlinite, cane sugar, quartz, Rochelle salt, topaz, tourmaline, and bone are among the naturally occurring materials that display piezoelectric qualities (dry bone has some piezoelectric properties due to the apatite crystals, and the piezoelectric effect is commonly assumed to work as a biological force sensor).
The development of lead-free piezoelectric materials has accelerated recently as a result of the European Union’s RoHS rule and the mounting environmental concern about the toxicity of lead-containing products. Thus far, the endeavor to create novel lead-free piezoelectric materials has yielded a range of new, ecologically safer piezoelectric materials.
Applications Best Suited for the Piezoelectric Effect
Piezoelectric materials have certain intrinsic properties that make them useful in a wide range of applications.
High Voltage and Power Sources
The electric cigarette lighter is one example of an application in this field. When a button is pressed, a spring-loaded hammer strikes a piezoelectric crystal, creating a high enough voltage to induce an electric current to pass over a tiny spark gap, heating and lighting the gas. The majority of gas burner and range models come with integrated piezo-based injection mechanisms.
Sensors
A piezoelectric sensor works on the basis of a physical dimension acting on two opposing faces of the sensing device, which is then converted into a force. The most popular use of sensors is for sound detection; these sensors are found in piezoelectric microphones and piezoelectric pickups for electrically amplified guitars. In particular, piezoelectric sensors are employed in high frequency sound ultrasonic transducers for industrial nondestructive testing and medical imaging.
Piezoelectric Motors
Piezo crystals are an essential tool for extremely precise object positioning, which makes them ideal for use in motors like the different motor series that Nanomotion offers. This is because very high voltages only slightly alter the crystal’s width, allowing for better-than-micrometer precision manipulation.
In terms of piezoelectric motors, an opposing ceramic plate is given directional force by the piezoelectric element in response to an electrical pulse, which causes the plate to move in the desired direction. When the piezoelectric element moves in opposition to a stationary platform, motion is produced (such as ceramic strips).
The right technology for developing our many lines of distinctive piezoelectric motors at Nanomotion was made possible by the properties of piezoelectric materials. Nanomotion has created a number of motor series using proprietary piezoelectric technology. The motors range in size from a single element (which produces 0.4 kg of force) to an eight element motor (which produces 3.2 kilograms of force). Nanomotion motors may readily mount to conventional low friction stages or other devices. They can drive both linear and rotational stages and have a wide dynamic speed range, from several microns per second to 250mm/sec. When in a static position, the inherent braking and servo dither elimination capabilities of Nanomotion’s motors are provided by their operating characteristics.
