01/18/2023
What Is a Piezo?
Piezo as noted in all formal sources (dictionaries, Wiki, etc) is a Greek root meaning pressure or push. It's combined with some other words to make new nouns and adjectives. For example a piezometer is a pressure meter; piezoresistor is an electronic component which changes its resistance when exposed to stress; and piezoelectric is an adjective describing a property of some special solid materials that can convert some of the energy from an applied pressure into electric charge.
What kind of materials? Well, a whole lot more than you might think. Although, for our purposes, the most important materials are man-made ceramics that happen to be really active (piezoceramics!). There are a lot of natural materials that exhibit piezoelectric properties, e.g. quartz crystal and even bone. We'll talk those up in a separate blog.
Piezo (the word) has more and more turned into a noun, as in "THE piezo." In common use, it could mean anything from a simple piezoceramic disk to a whole assembled component or device that has some essential piezoelectric material as an integral part. Oddly enough, 50-odd years ago there appeared in the 1967 Random House Dictionary the word piezoid, a noun, with the definition "a completed crystal blank, esp. after attachment of electrodes to the faces" which is pretty close to the current piezo in meaning.
Here we'll take a generic applications perspective and use "piezo" for a device, and we'll say that "piezo material" is a solid which, when deformed by applied stress, produces usable electric charge, and when subjected to applied electric field, deforms itself. A medium in which there is coupling, i.e. free reversible interchange, of electric and elastic energy. "Fascinating Captain," as Spock would say.
By Rob Carter
https://bit.ly/3WaibTy is a division of Mide Technology. Mide is a proud member of the Hutchinson team.