Scientists unlock vital clue to strange quirk of static electricity
Ars Technica 2025-02-19
Static electricity—specifically the triboelectric effect, aka contact electrification—is ubiquitous in our daily lives, found in such things as a balloon rubbed against one's hair or styrofoam packing peanuts sticking to a cat's fur (as well as human skin, glass tabletops, and just about anywhere you don't want packing peanuts to be). The most basic physics is well understood, but long-standing mysteries remain, most notably how different materials exchange positive and negative charges—sometimes ordering themselves into a predictable series, but sometimes appearing completely random.
Now scientists at the Institute of Science and Technology Austria (ISTA) have identified a critical factor explaining that inherent unpredictability: It's the contact history of given materials that controls how they exchange charges in contact electrification. They described their findings in a new paper published in the journal Nature.
Johan Carl Wilcke published the first so-called "triboelectric series" in 1757 to describe the tendency of different materials to self-order based on how they develop a positive or negative charge. A material toward the bottom of the list, like hair, will acquire a more negative charge when it comes into contact with a material near the top of the list, like a rubber balloon.