Scientists spot piezoelectric effect in liquids for the first time

Source: The post is based on the article “Scientists spot piezoelectric effect in liquids for the first time” published in The Hindu on 31st March 2023

What is the News?

For the first time, scientists have reported evidence of the piezoelectric effect in liquids.

What is the Piezoelectric effect?

Piezoelectric Effect is the ability of certain materials to generate an electric charge in response to applied mechanical stress. 

One of the unique characteristics of the piezoelectric effect is that it is reversible. This means materials exhibiting the direct piezoelectric effect (the generation of electricity when stress is applied) also exhibit the converse piezoelectric effect (the generation of stress when an electric field is applied).

Quartz is the most famous piezoelectric crystal. It is used in this capacity in analog wristwatches and clocks. Such crystals are used in cigarette lighters, electric guitars, TV remote controls, audio transducers, and other instruments where converting mechanical stress to a current is useful.

Note: It is believed that the Piezoelectric effect was discovered in 1880, in quartz, by Jacques and Pierre Curie.

Why is the Piezoelectric effect in liquids surprising?

The Piezoelectric effect has been known for 143 years and in this time has been observed only in solids.

The reason the piezoelectric effect has only been expected in solids thus far is that the body being squeezed needs to have an organized structure, like the pyramids of quartz. Liquids don’t have such structure; instead, they take the shape of their container.

What are the implications of this discovery?

The discovery of Piezoelectric effect in liquids opens the door to applications that have previously not been accessible with solid-state materials and are more readily recyclable and in many instances pose fewer environmental issues than many currently used piezoelectric materials.

The liquids also displayed the inverse piezoelectric effect which means they became distorted when an electric charge was applied, this fact could be used to control how the liquids bent light passing through them by passing different currents through them.

Hence, using this simple control mechanism, vials of these liquids could be used for lenses with dynamic focusing abilities.