What is Piezoelectricity?

May 10, 2023

Researchers from the Indian Institute of Technology Madras (IIT-M) and the Defence Research and Development Organisation (DRDO) recently developed piezoelectric MEMS (micro electro mechanical system) technology for underwater communication.

About Piezoelectricity:

  • Piezoelectricity (also called the piezoelectric effect) is the appearance of an electrical potential (a voltage, in other words) across the sides of a crystal when you subject it to mechanical stress.
  • In the reverse piezoelectric effect, a crystal becomes mechanically stressed (deformed in shape) when a voltage is applied across its opposite faces.
  • Thus, Piezoelectric materials allow the conversion of energy from the mechanical domain to the electrical domain and vice versa.
  • It is due to the spontaneous separation of charge with certain crystal structures under the right conditions.
  • There are a wide variety of materials which exhibit this phenomenon, including natural quartz crystals, semi-crystalline polyvinylidene polymer, polycrystalline piezoceramic, bone and even wood.
  • Applications:
    • They can be used to create various sensors or actuators.
    • Piezoelectric transducers are common in ultrasonic applications, such as intrusion detectors and alarms. 
    • Piezoelectric devices are employed at AF(audio frequencies) as pickups, microphones, earphones, beepers, and buzzers. 
    • In wireless applications, piezoelectricity makes it possible to use crystals and ceramics as oscillators that generate predictable and stable signals at RF (radio frequencies).