A water drop can create an extra burst of charge when its advancing edge catches on a microscopic defect and tears free. The strongest runs approached ten times the study's ordinary wet-to-dry signal, but the real insight is how surface roughness controls the effect.
Every time a raindrop sticks and slips as it runs down a surface, it can generate a tiny electrical charge. In March 2025, RMIT and University of Melbourne researchers discovered a previously overlooked charging mechanism that can produce about 10 times more charge than the familiar wet-to-dry process.
The Long View