Raindrops are tiny lightning bolts, and they’re corroding cars, study finds
Summary
A Max Planck Institute study shows raindrops can carry electrical charges up to about 9,000 volts, enabling dielectric breakdown of insulating coatings and causing corrosion of copper beneath coatings. Experiments on multiple substrates demonstrate that charged drops breach coatings and accelerate corrosion, with thicker films offering more protection. The findings have broad implications for composites and protective layers in outdoor electronics and infrastructure, and are published in Nature (2026).