Piezoelectric transducer

Piezoelectric transducer


Piezoelectricity or 'pressure electricity' is the ability of some materials (notably crystals and certain ceramics, including bone) to generate an applied mechanical stress in response to electric potential (voltage). This may take the form of a separation of electric charge across the crystal lattice. If the material is not short-circuited, the applied charge induces a voltage across the material. The word is derived from the Greek piezo or piezein, which means to squeeze or press.

The piezoelectric effect is reversible in that materials exhibiting the direct piezoelectric effect (the production of electricity when stress is applied) also exhibit the reverse piezoelectric effect (the production of stress and/or strain when an electric field is applied). For example, lead zirconate titanate crystals will exhibit a maximum shape change of about 0.1% of the original dimension.

The effect finds useful applications such as the production and detection of sound, generation of high voltages, electronic frequency generation, microbalances, and ultra fine focusing of optical assemblies. It is also the basis of a number of scientific instrumental techniques with atomic resolution, the scanning probe microscopies such as STM, AFM, MTA, SNOM etc, and everyday uses such as acting as the ignition source for cigarette lighters and push-start propane barbecues.


A transducer is a device, usually electrical, electronic, electro-mechanical, electromagnetic, photonic, or photovoltaic that converts one type of energy or physical attribute to another for various purposes including measurement or information transfer (for example, pressure sensors).

There are three kinds of transducers. A sensor is used to detect a parameter in one form and report it in another form of energy (usually an electrical or digital signal), such as a tachometer. An actuator is used for the transformation of energy or in other words, actuator is the one which gets actuated or stands responsible for the output action, in that it converts electrical signal into generally nonelectrical energy. An example of an actuator is a loudspeaker which converts an electrical signal into a variable magnetic field and, subsequently, into acoustic waves. The third kind of transducer has both functions -- for example, a typical ultrasonic transducer switches back and forth many times a second between acting as an actuator to produce ultrasonic waves, and acting as a sensor to detect ultrasonic waves.


A piezoelectric sensor is a device that uses the piezoelectric electricity to measure pressure, acceleration, strain or force by converting them to an electrical signal. Applications Piezoelectric sensors have proven to be versatile tools for the measurement of various processes.