piezo-, piez- +
(Greek: to press; pressure; to squeeze)
2. Awareness of or feeling pressure: Lorna thought she was dreaming of experiencing piesesthesia; however, in fact it was real because when she woke up, she realized that her cat was sleeping on her chest.
2. An electromechanical effect by which mechanical forces acting upon a ferroelectric material can produce an electrical response, and electrical forces can produce a mechanical response.
It consists of a small, spring-loaded hammer which, when a button is pressed, hits a quartz crystal which produces a spark to ignite the gas. A piezo ignition system creates a spark to light the gas by triggering an impact upon a special crystal. No electric connection is required.
Piezo ignition systems can operate by either a lever, separate push button, or built into the control knob. Only one spark per turn of the knob or press of the button is generated.
2. The study of chemical reactions that occur at very high pressures; such as, under the earth's crust.
2. Relating to or involving piezoelectricity; such as, piezoelectric plates.
A description of the ability of a solid to generate a voltage when subjected to a mechanical stress, or the ability to generate a mechanical force when subjected to a voltage.
When compressed, some crystalline materials will produce a voltage proportional to the applied pressure; when an electric field is applied across the material, there is a corresponding change of shape.
Japanese manufacturers have shared their piezoelectric discoveries, quickly overcoming technical and manufacturing challenges and creating new markets. Japanese efforts in materials research have created piezoceramic materials competitive with the U.S. materials, but free of expensive patent restrictions.
Major Japanese piezoelectric developments include new designs of piezoceramic filters, used in radios and televisions, piezo buzzers and audio transducers that can be connected directly into electronic circuits, and the piezoelectric igniter which generates sparks for small engine ignition systems (and gas-grill lighters) by compressing a ceramic disc.
Ultrasonic transducers that could transmit sound waves through the air had existed for quite some time, but first saw major commercial use in early television remote controls.
These transducers now are mounted on several car models as an echolocation device, helping the driver determine the distance from the rear of the car to any objects that may be in its path.
Piezoelectricity has the function of certain crystals to generate a voltage in response to applied mechanical stress.
The result is reversible in that the piezoelectric crystals, subject to an externally applied voltage, can change shape by a minimal amount.
The change is in the degree of nanometers although there are useful applications; such as, the production and detection of sound, the generation of high voltages, electronic frequency generation, and the ultrafine focusing of optical assemblies.
A characteristic known as pyroelectricity, which is the ability of certain mineral crystals to generate electrical charges when heated, was determined as early as the 18th century, and was named by David Brewster in 1824.
In 1880, the brothers Pierre Curie and Jacques Curie predicted and demonstrated piezoelectricity using tinfoil, glue, wire, magnets, and a jeweler's saw.
They showed that crystals of tourmaline, quartz, topaz, cane sugar, and Rochelle salt (sodium potassium tartrate tetrahydrate) generate electrical polarization from mechanical stress.
Quartz and Rochelle salt exhibited the most piezoelectricity. There are twenty known natural crystal classes that exhibit direct piezoelectricity.
2. The generation of an electric charge in certain nonconducting materials, such as quartz crystals and ceramics, when they are subjected to mechanical stress including pressure or vibration, or the generation of vibrations in such materials when they are subjected to an electric field.
Piezoelectric materials exposed to a fairly constant electric field tend to vibrate at a precise frequency with very little variation, making them useful as time-keeping devices in electronic clocks, as used in wristwatches, and computers.