Definition
Piezoelectric describes a material's ability to generate electricity when subjected to mechanical stress or pressure, and conversely, to deform when an electric field is applied. Think of how some lighters create a spark when you press a button. This effect occurs due to the alignment of electric charges in the material's crystalline structure. Piezoelectric materials are used in sensors, actuators, and energy harvesting devices. Quartz crystals in watches are a common example of piezoelectricity in action. It's a reversible process.