Science

Piezoelectricity Introduction

 

Piezoelectricity is a fascinating and innovative concept in the realm of materials science and engineering. It refers to the electric charge that accumulates in certain materials in response to applied mechanical stress. It is derived from the Greek words "piezein," meaning "to press," and "electricity," piezoelectricity describes the ability of specific materials to generate an electrical charge when subjected to force or pressure. Piezoelectricity is about the interaction between mechanical stress and electrical charge. Certain materials, known as piezoelectric materials, exhibit this unique property. When these materials are compressed, stretched, or otherwise deformed, they produce an electric charge. When an electric field is applied to them, they can change shape or deform. Piezoelectricity comes from the internal structure of piezoelectric materials. These materials have a crystalline structure with asymmetrical charge distributions. When mechanical stress is applied, it causes a shift in these internal charge distributions, leading to the generation of an electric field. This phenomenon occurs in materials such as quartz, certain ceramics, and even some biological materials like bone.

Applications

1. Energy Harvesting: Piezoelectric materials are increasingly used in energy harvesting technologies to capture and convert mechanical vibrations into electrical energy. This has applications in powering small electronic devices and sensors.

2. Medical Devices: In the medical field, piezoelectric materials are used in ultrasound imaging, where they generate and detect sound waves to create detailed images of internal body structures.

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3. Aerospace and Defence: In aerospace and defence applications, piezoelectric materials are used in vibration sensors, structural health monitoring, and active vibration control systems. Piezoelectricity was first discovered in 1880 by two brothers and French scientists, Jacques and Pierre Curie. When they were experimenting with different crystals, they found out that when they applied some mechanical pressure to a crystal like quartz, it released an electrical charge. This is now known as the piezoelectric effect. In World War I, piezoelectricity was used for practical applications in sonar. Sonar works by connecting a voltage to a piezoelectric transmitter. This is the inverse piezoelectric effect in action, which converts electrical energy into mechanical sound waves because the piezoelectric effect is known as the conversion of mechanical pressure to electrical charge. The sound waves travel through the water till they hit an object. They then return back to the source receiver after being reflected. This receiver uses the direct piezoelectric effect to convert sound waves into an electrical voltage, which a signal-processing device can then process. Using the time between when the signal left and when it returned, an object’s distance can easily be calculated. In World WarIIadvanced the technology even further as researchers from the United States, Russia, and Japan worked to craft new man-made piezoelectric materials called ferroelectrics. This research led to two man-made materials used alongside natural quartz crystal, barium titanate, and lead zirconate titanate