Solving the longstanding mystery of how friction leads to static electricity
Phys.org - Tue 10 Sep 17:20 GMT

Most people have experienced the hair-raising effect of rubbing a balloon on their head or the subtle spark caused by dragging socked feet across the carpet. Although these experiences are common, a detailed understanding of how they occur has eluded scientis…

  Now a Northwestern University team developed a new model that shows that rubbing two objects together produces static electricity, or triboelectricity, by bending the tiny protrusions on the surface of materials.

  This new understanding could have important implications for existing electrostatic applications, such as energy harvesting and printing, as well as for avoiding potential dangers, such as fires started by sparks from static electricity.

  Laurence Marks, professor of materials science and engineering in Northwestern's McCormick School of Engineering, led the study.

  Marks's team found that these deformations give rise to voltages that ultimately cause static charging.

  Using a simple model, the Northwestern team showed that voltages arising from the bending protrusions during rubbing are, indeed, large enough to cause static electricity.

  "NSF funds research like this in materials science and engineering for new knowledge that can one day open new opportunities."