The first documentation of static electricity dates back to 600 BC. However, even after 2,600 years of small impacts, researchers couldn’t fully explain how rubbing two objects together causes this. But according to a team from Northwestern University, the mystery has finally been solved. As explained in a September 17 study published in the journal Nano lettersthe answer is ‘surprisingly simple’. It’s all about small imperfections.
“People tried, but they couldn’t explain experimental results without making assumptions that weren’t warranted or justifiable,” says Lawrence Marks, professor emeritus of materials science and engineering. said on September 18. “We can now… Just having different deformations – and therefore different charges – on the front and back of something that is sliding leads to current flow.”
Marks and their colleagues first began investigating the properties of static electricity in 2019, when they discovered that rubbing two materials together deforms tiny variations on the surface of any object. This move subsequently generated tensions. From there, the team created a new model that relies on the concept known as “elastic shear,” which happens when an object resists a sliding force, creating friction. Once friction builds up on either side of the nano-sized deformations, the difference in electrical charge can cause a current – and the resulting shock.
“We have developed a new model that calculates the electric current. The current values for a range of different cases were in good agreement with the experimental results,” said Marks.
Marks notes that while most people associate static electricity with demonstrations such as hair-raising basic science experiments or touching a doorknob after rubbing your pet’s fur, the electrical charge actually exerts an enormous influence on the world “in both simple and profound ways.” An everyday example can be seen when the loaded grains of a coffee grinder change the flavor of beans. But static shock is also responsible for much more serious problems, such as dosing complications for powdered medications and industrial fires. Most experts believe that Hindenburg The tragedy was likely the result of fires caused by static electricity. By better understanding the mechanisms involved, experts from different sectors can help make their products more effective and working conditions safer.
[Related: Butterflies and moths suck up pollen with static electricity.]
“Earth would probably not be a planet without an important step in the clumping together of particles to form planets, which happens due to the static electricity generated by colliding grains,” Marks explains. “It’s amazing how much of our lives is affected by static electricity and how much of the universe depends on it.” And now, after thousands of years, that key phenomenon has an exact explanation.
