Every once in a while a study, a new piece of information, a laboratory experiment, completely erases a previous model of scientific understanding. Newton did it to Aristotle. Einstein did it to Newton. But, who would have thought that the prevailing model for the basics of static charge generation would go the way of the Precopernican Geocentric model of the universe? Well according to a recently published paper, we now have a completely new theory on how static charges are generated when two materials contact and then separate. This will certainly have an impact on 8th grade science curricula but it also shows us how little we know about the most basic aspects of our environment.
Using Kelvin force microscopy scans, the authors show that charges are not transferred uniformly between materials when they are rubbed together. They state that interacting materials actually pick up a random combination of both positive and negative charges when they contact and separate; Previously, we assumed that each material would either charge negatively or positively because that is the net effect. However, their study shows that each material actually picks up pockets of each polarity where some of the isolated pocket charges measure almost 100 times greater than the net charge on the overall surface. They also opine that this is not the result of an exchange of electrons but the result of an actual chemical transfer. We'll comment on this more later including what we believe may be some implications to the control of electrostatic discharge (ESD) with ionization and static dissipative flooring. In the meantime you can access the full study,The Mosaic of Surface Charge in Contact Electrification or you can read a well sythesized synopsis called What You Learned About Static Electricity is Wrong in WIRED Magazine at this link.
How will this impact static prevention stategies like ESD flooring used in facilities where people handle ESD sensitive electronic parts? This may explain the phenomena of tribocharging and why rubber flooring charges shoe soles less than conductive and static dissiaptive vinyl and epoxy floors. It may provide insight into why old shoes charge up more than new plasticizer rich shoe soles and why conductive carpet offers charge generation adavantage compared to safer, static dissipative carpet tiles like Staticworx ShadowFX. More to come!
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