The first recorded mention of static electricity can be traced back to as early as 600 BC. Despite over 2,600 years of continuous exploration, researchers have still been unable to fully explain why rubbing two objects together results in the generation of static electricity. Recently, a team of researchers from Northwestern University in the United States has finally found an answer to this puzzle. Their latest research, published on September 17 in the journal “Nano Letters,” reveals that the solution is “surprisingly simple” and all has to do with nano-scale defects on the surfaces of objects.
“People have tried before, but couldn’t come up with a rational explanation that doesn’t involve assumptions,” said Lawrence Marks, a distinguished professor of materials science and engineering on September 18, “We can now… simply by having different deformations on the front and back of a sliding object, result in different charges, leading to the generation of electricity.”
Marks and his colleagues began studying the properties of static electricity back in 2019, where they discovered that rubbing two materials together causes small irregularities on the surface of each object to change, generating voltage. Subsequently, the team developed a new model based on a concept called “elastic shearing,” which occurs as objects resist the force of sliding. Once friction accumulates on one side of the nano-scale deformation, the difference in charges can generate electricity and trigger electric shocks.
“We have developed a new model to calculate the current. The values of the current under different conditions match the experimental results,” said Marks.
While most people associate static electricity with experiments that make hair stand on end or touching a doorknob after rubbing a pet’s fur, the impact of charges on the world extends far beyond these scenarios. For instance, charged particles in a coffee grinder can alter the flavor of the beans. Static electric shocks can also lead to serious issues, such as the complexities of powdered medication dosages and industrial fires. For example, most experts believe that the Hindenburg tragedy may have been related to a fire sparked by static electricity. By better understanding the mechanisms involved, experts from various industries can help improve the effectiveness of their products and enhance safety conditions at work.
“If it weren’t for the static electricity generated by colliding particles, the Earth might not have become a planet, as this process contributed to the formation of planets,” explained Marks, “The profound impact of static electricity on our lives and the universe’s dependence on it is truly astonishing.” Now, after thousands of years, this key phenomenon finally has a definitive explanation.