Piezoelectricity

Syllabus:GS3/Science and Technology

Context

• The Command Hospital Pune performed two successful piezoelectric bone conduction hearing implants, making it the first government hospital in the country to do the medical operations.

What is Piezoelectricity?

• Piezoelectric Effect is the ability of certain materials to generate an electric charge in response to applied mechanical stress.
• History: Piezoelectricity was discovered in 1880 by Pierre and Paul-Jacques Curie, who found that when they compressed certain types of crystals including quartz, tourmaline, and Rochelle salt, along certain axes, a voltage was produced on the surface of the crystal.

 Piezoelectric Principle 

• Principle: This property is the result of their unusual crystal structures. Usually, the charges on atoms in the molecules that make them up are symmetric on two sides of an axis. 
• When some stress is applied, the molecule becomes distorted and the asymmetry of charges gives rise to a small electric current.
• Some materials also display an inverse piezoelectric effect, where the application of an electric current induces a mechanical deformation.

Applications

• Both direct and inverse piezoelectric materials are used in pressure sensors, accelerometers, and acoustic devices – where their ability to convert mechanical signals into electrical signals is crucial. 
• The material is also used in devices such as microphones, phonograph pickups, and wave filters in telephone-communications systems.

Source: IE