• High voltage and power sources
• Sensors
• Actuators
• Frequency standard and Motors
• Reduction of vibrations and noise and Infertility treatment

Sensors

A piezoelectric sensor is a device that uses the piezoelectric effect to measure pressure, acceleration, strain or force by converting them to an electrical charge

The principle of operation of a piezoelectric sensor is that a physical dimension, transformed into a force, acts on two opposing faces of the sensing element. Depending on the design of a sensor, different "modes" to load the piezoelectric element can be used: longitudinal, transversal and shear.

Detection of pressure variations in the form of sound is

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  Guitar Picking sensors

the most common sensor application, e.g. piezoelectric microphones (sound waves bend the piezoelectric material, creating a changing voltage) and piezoelectric pickups for Acoustic-electric guitars. A piezo sensor attached to the body of an instrument is known as a contact microphone.

Piezoelectric sensors especially are used with high frequency sound in ultrasonic transducers for medical imaging and also industrial nondestructive testing (NDT).

For many sensing techniques, the sensor can act as both a sensor and an actuator – often the term transducer is preferred when the device acts in this dual capacity, but most piezo devices have this property of reversibility whether it is used or not.

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  Piezo Fuse

Ultrasonic transducers, for example, can inject ultrasound waves into the body, receive the returned wave, and convert it to an electrical signal (a voltage). Most medical ultrasound transducers are piezoelectric.

In addition to those mentioned above, various sensor applications include:

Piezoelectric microbalances are used as very sensitive chemical and biological sensors.

Piezoelectric elements are also used in the detection and generation of sonar waves.

Piezos are sometimes used in strain gauges.

Piezoelectric transducers are used in electronic drum pads to detect the impact of the drummer's sticks.

Automotive engine management systems use piezoelectric transducers to detect detonation by sampling the vibrations of the engine block and also to detect the precise moment of fuel injection (needle lift sensors).

Ultrasonic piezo sensors are used in the detection of acoustic emissions in acoustic emission testing.

Crystal earpieces are sometimes used in old or low power radios.