The piezoelectric effect is the ability of certain materials to generate an electric charge in response to applied mechanical stress. The word “piezoelectricity” means electricity resulting from pressure and latent heat. It is derived from the Greek piezo or pyro, meaning press or burn, and electric or electron, meaning amber, one of the first substances found to exhibit this effect.
The piezoelectric effect was discovered in 1880 by French physicists Jacques and Pierre Curie. They found that when pressure was applied to certain crystals, such as quartz, a charge developed on their surface. This phenomenon is known as the direct piezoelectric effect.
Converse piezoelectricity was discovered in 1917 by Paul Langevin. He found that when an electric field was applied to a crystal, it changed shape slightly. This phenomenon is known as the inverse piezoelectric effect and can be used to create electrical signals from mechanical vibrations ( Piezo-electric sensor).
Piezoelectric materials are widely used in microphones, loudspeakers, vibrating motors, sensors (pressure, acceleration), actuators , inkjet printers’ nozzles , ultrasonic humidifiers/cleaners . Application of larger voltages may cause dielectric breakdown and permanent damage due largely to electrostriction . Electrostrictive ceramics have been developed for high-field applications but are not yet commercially available .