Posted on behalf of Melanie Smith.

Most of us will have generated static electricity by rubbing a balloon on hair or a woolly jumper, and then sticking the charged balloon to the ceiling. The standard, physics-class wisdom is that the rubbing transfers electrons from hair to balloon, causing the surfaces to become positively or negatively charged and therefore attracted to each other, a process called contact electrification.

But in a study published in Science this week, a group of scientists led by Bartosz Grzybowski of Northwestern University show that static electricity isn’t quite as simple as your physics teacher may have made out. Using a technique called Kelvin probe microscopy, they measured the charges on different regions of an electrified surface, and found that the spread of positive and negative charge is actually far less uniform than has been thought.

Instead, a charged surface is a mosaic of patches of positively charged protons and negatively charged electrons. A surface’s net charge depends on which patch is in the majority. These mosaics emerge through the intricacies of the exchange of material between the two objects.

Static shocks and charges can cause excessive tension between materials, often leading to stretching or breaking. The new study may help us understand the operation of industrial substances and of grounding, which is used to drain static charge from an object. It also presents a fresh crossover between scientific disciplines, in the form of a topic investigated by chemists and engineers but rooted in molecular physics.

Image: <a href= “https://www.flickr.com/photos/patdavid/”>avhell, via Flickr under Creative Commons.