Why petting your cat generates static electricity

Do you get a mild electric shock when you pet a cat? Scientists say they’ve finally figured out why it happens, and no, it’s not a love shock.

Movements like petting generate static electricity. And for the first time, researchers at Northwestern University say they’ve understood how this phenomenon happens.

“If you put your hand on a cat, you don’t get an electric charge. But if you stroke a cat’s fur, you get an electric charge,” said Professor Lawrence Marks. Independent Friday.

When your hand slides over a cat’s fur, the front and back parts of the cat are subjected to different forces. It is this difference in forces that causes electrical charges to build up in those areas, generating an electrical current that can lead to an electric shock.

“The mere presence of different deformations – and therefore different charges – at the front and back of a sliding object results in a current,” Marks, the work’s lead author, said in a statement from the school.

His study was Published this week in the magazine Nano letters.

But static electricity was first reported in 600 B.C. by the Greek philosopher Thales of Miletus. He rubbed a piece of amber on fur and noticed that the fur attracted dust. Since then, scientists say it has become clear that rubbing induces a static charge in all insulating materials, such as fur. But that’s where the scientific consensus ends.

Marks and the student researchers began working on filling the void in 2019, when they reported that rubbing two materials together Bends small parts on their surfacesWhich led to the advent of electricity. And even with the spread of the Corona virus, “they kept working.”

“Well, we did some work on tribology. So, that kind of thing like friction. And we also did some work on electroelasticity, which is how we get voltages from curved things,” Marks said Friday. “And then I realized we could combine the two to start understanding how we get charge, which is triboelectricity.”

They have since developed a new model for calculating electric currents using what is called “elastic shear.” Elastic shear can occur. When a material resists a sliding force, this extra friction causes electrical charges to move.

But while static electricity may be a cute idea when petting cats, sparks can cause industrial fires and explosions. And they can be a problem with fixed doses of powdered pharmaceuticals. Scientists hope these findings will provide a solution to this problem.

“If we understand, we can prevent; we can control,” Marx explained.