Ever looked inside a stove lighter and wondered where the spark comes from? The spark is created by piezoelectricity.
Piezoelectricity is a remarkable phenomenon whereby some materials – including quartz, ceramics such as lead zirconate titanate (PZT), and even certain biological substances like bone and the tendons – can generate an electric charge in response to mechanical stress. 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.
The term “piezoelectric” itself originates from the Greek words “piezein,” meaning ‘to squeeze’, and “elektron”, for amber – a material known for its association with static electricity.
Some materials also display an inverse piezoelectric effect, where the application of an electric current induces a mechanical deformation.
Both direct and inverse piezoelectric materials are widely used in pressure sensors, accelerometers, and acoustic devices – where their ability to convert mechanical signals into electrical signals is crucial. The piezoelectric effect is also what made quartz watches so common and, over time, affordable.
