Piezoelectric is the electric charge that accumulates in certain solid materials (such as crystals, certain ceramics, and biological matter such as bone, DNA and various proteins) in response to applied mechanical stress.
The word piezoelectric means electricity resulting from pressure and latent heat , ceramic PZT materials are classified as functional ceramics. in sensors, they can convert pressure and acceleration into electrical signals that convert voltage into vibrations or deformations in sound waves and ultrasonic transducers and actuators and is exploited in a number of useful applications, such as the production and detection of sound, piezoelectric inkjet printing, generation of high voltages, electronic frequency generation, microbalances, to drive an ultrasonic nozzle, and ultrafine focusing of optical assemblies.
Piezoelectric sensors especially are used with high frequency sound in ultrasonic transducers for medical imaging and also industrial nondestructive testing.
In addition to those mentioned above, various sensor applications include:
- Piezoelectric elements are also used in the detection and generation of sonar waves.
- Piezoelectric materials are used in single-axis and dual-axis tilt sensing.
- Power monitoring in high power applications (e.g. medical treatment, sonochemistry and industrial processing).
- Piezoelectric microbalances are used as very sensitive chemical and biological sensors.
- Piezos are sometimes used in strain gauges.
- A piezoelectric transducer was used in the penetrometer instrument on the Huygens Probe.
- Piezoelectric transducers are used in electronic drum pads to detect the impact of the drummer’s sticks, and to detect muscle movements in medical acceleromyography.
- Automotive engine management systems use piezoelectric transducers to detect Engine knock (Knock Sensor, KS), also known as detonation, at certain hertz frequencies. A piezoelectric transducer is also used in fuel injection systems to measure manifold absolute pressure (MAP sensor) to determine engine load, and ultimately the fuel injectors milliseconds of on time.
- Ultrasonic piezo sensors are used in the detection of acoustic emissions in acoustic emission testing.