Piezoelectric materials are a class of materials that have the ability to generate an electric charge in response to mechanical stress, and conversely, to generate a mechanical stress in response to an electric field. This unique property makes piezoelectric materials useful in a variety of applications, such as sensors, actuators, energy harvesting devices, and medical imaging equipment. Research in this area typically focuses on developing new piezoelectric materials with improved properties, exploring novel applications of piezoelectric materials, and understanding the underlying mechanisms that govern their behavior.