From ice to lightning: new study shows how flexoelectricity powers storms

According to a recent study, when regular hexagonal ice is bent or twisted, it can produce electricity. Electric polarisation can be produced by deformed ice crystals due to a phenomenon called flexoelectricity. This characteristic, according to scientists, may finally explain how thunderstorms build up the enormous electrical charges that cause lightning.

• Where was this study carried out?

This research was recently published in a scientific study and provides a timely advance in our understanding of storm physics. It focuses on natural processes that occur within thunderclouds but was confirmed in laboratory experiments.

• Flexoelectricity: How does this phenomenon works?

During thunderstorms, ice particles are constantly colliding, bending, and twisting under turbulent forces. These deformations produce charges strong enough to separate, eventually building powerful electric fields inside the cloud. The effect has been observed across a wide temperature range up to 0°C. At extreme cold, below –113°C, ice surfaces also display ferroelectric behaviour, meaning their polarisation can switch direction under an external field, adding to the charge generation process.

• Why It Matters?

For decades, researchers have known that collisions between ice crystals and larger particles, such as graupel, play a central role in storm electrification. However, because ice is not piezoelectric and typically does not produce electricity under simple compression, the precise mechanism underlying the charge build-up has been unclear.

In addition to answering a long-standing meteorological question, the results could lead to new applications. Sensors, energy harvesting and other devices designed to operate in extremely cold temperatures could make use of ice's flexoelectricity.