All ferroelectric materials possess a property known as piezoelectricity in which an applied mechanical force can generate an electrical current and an applied electrical field can elicit a mechanical response. Ferroelectric materials are used in a wide variety of industrial applications, from ultrasound and sonar to capacitors, transducers, vibration sensors and ultrasensitive infrared cameras. Now, an international team of scientists led by Penn State may have solved the 30-year-old riddle of why certain ferroelectric crystals exhibit extremely strong piezoelectric responses.