Piezoelectric Material in Liquid Form Discovered For The First Time

Recently, chemists at Michigan State University have observed the piezoelectric effect in a liquid for the first time. The research team pointed out that liquid piezoelectric materials are more environmentally friendly than solid piezoelectric materials and are expected to "show their talents" in many fields. The related research was published in the latest issue of "Physical Chemistry Letters".

So far, all piezoelectric materials have been solid. Such materials are called piezoelectric because they have the property of holding an electric charge under normal conditions and releasing it under pressure. These solid piezoelectric materials are now widely used in products such as sonar equipment, guitar pickups and cell phone speakers. In the latest study, Michigan State University chemist Iqbal Hussein and others discovered the first piezoelectric material that exists in liquid form at room temperature.

A newly discovered liquid piezoelectric material is an ionic liquid made from a salt of flexible organic cations with asymmetry and weakly coordinating anions with symmetry. Electricity builds up inside these ionic liquids, and the researchers found that when a piston applied pressure to a sample of the ionic liquid inside the cylinder, the electricity was released. They also found that the amount of electricity released was proportional to the applied pressure. Further tests showed that the optical properties of the ionic liquid changed when it delivered an electric current, and in some cases, the way the liquid bent light.

The research team is still unable to explain why ionic liquids are piezoelectric, but they believe that applying pressure may help to separate the charges in the liquid, releasing some of them. They plan to continue studying the material for answers.