ANDREW PAUL WRITES IN POPULAR SCIENCE, September 18, 2024, “After 2600 Years, We Finally Know How Static Electricity Really Works.”
Well isn’t it about time? No, it’s about nano particles.
Size Matters. “The first documentation of static electricity,” Andrew Paul recounts, “dates back to 600 BCE. Even after 2,600 years’ worth of tiny shocks, however, researchers couldn’t fully explain how rubbing two objects together causes it. But according to a team at Northwestern University, the mystery is finally solved. As explained in a September 17 study published in the journal Nano Letters, the answer is ‘surprisingly simple.’ It all has to do with little imperfections.”
Static electricity occurs in part due to nanoscale imperfections on object surfaces. Image from Deposit Photos via Popular Science.
Paul quotes one of the researchers: “People have tried, but they could not explain experimental results without making assumptions that were not justified or justifiable,” Laurence Marks, a professor emeritus of materials science and engineering, said on September 18. “We now can… Just having different deformations—and therefore different charges—at the front and back of something sliding leads to current.”
Triboelectricity Details. The Nano Letters paper by Karl P. Olson and Laurence D. Marks addresses “What Puts the ‘Tribo’ in Triboelectricity?” In general tribology, according to Wikipedia, “is the science and engineering of understanding friction, lubrication and wear phenomena for interacting surfaces in relative motion. It is highly interdisciplinary, drawing on many academic fields, including physics, chemistry, materials science, mathematics, biology and engineering.”
In their Abstract, Olson and Marks explain, “When sliding is taking place, there is symmetry breaking due to elastic shear, so the front of the sliding body experiences different elastic strains from the back.”
Image from Olson and Marks.
“Consequently,” the researchers say, “the polarization and associated charges at the front and back are not the same, and the difference between the two leads to current flow similar to the difference in air pressure above and below a plane’s wing leading to lift.”
Me, Once A Staff Tribologist? During undergrad years in a summer intern job with U.S. Steel Corp (whence my WPI scholarship), I was a staff tribologist, sorta: The idea of studying friction under sustained motion suited the problem of wire production to a tee: Steel wire gets its required diameter through successive drawing through hardened dies, the process lubricated by carefully optimized lubricants.
I was given a selection of potential lubricants, some soaplike, others oily, others powered. My job was to devise a die apparatus that could accurately quantify the drawing requirement for each lube.
Informal Team Support. The machinists of our lab’s model shop were very busy supplying the research facility with required gadgets and tooling. But, bless ’em, they took interest in this kid “staff tribologist” and occasionally moved my designs up in the fabrication queue.
Before the summer was over, I presented a polished report rating the potential wire lubricants. Of course, I cannot divulge which they are. I do recall that none generated static electricity, however. ds
© Dennis Simanaitis, SimanaitisSays.com, 2024