Rain is a micro-lightning: scientists discovered how droplets penetrate car protection

Researchers from the Max Planck Institute for Polymer Research have uncovered an unexpected mechanism for metal corrosion under protective coatings. It turns out that water droplets sliding down various surfaces can accumulate an electric charge reaching several thousand volts. When such a charged droplet approaches coated metal, it creates a powerful electric field that triggers an electrical breakdown of the protective layer. This allows water to make direct contact with the metal surface, initiating corrosion even in the absence of visible coating defects. Previously, it was believed that corrosion began exclusively through pre-existing cracks or paint damage. This discovery, published in the journal Nature, changes the understanding of protective material durability and highlights the need to develop new anti-corrosion methods that account for the electrostatic properties of liquids.