Faraday Cages? The Surprising Facts
After 10 years, the science fiction show The X-Files recently returned to television. In the very first new episode, there is a scene where scientists are studying apparent alien technology, all the while protected from potential harm because the technology is housed in a Faraday cage.
For most people, Faraday cages seem like the stuff of science fiction – boxes built to protect folks with overactive imaginations who fear the world will end with a sudden electromagnetic pulse or EMP. But what if I told you that most people benefit from at least one Faraday cage almost every day?
The first Faraday cage was built back in the 1830’s, by Michael Faraday, hence the name. Faraday was an experimental physicist who worked primarily studying electromagnetism and electrochemistry.
Rumor has it that Albert Einstein had a photo of Faraday that he kept on the wall of his study, right next to his picture of Isaac Newton.
One day Faraday noted that during one of his experiments, excess energy from a charged conductor only rested on the exterior of a container, for some reason not penetrating through the container to ground as electricity typically does.
He set about constructing a box to prove his theory that the inside was somehow shielded from the electrical charge.
He built a room, entirely lined with metal foil and subjected it to high powered electrostatic discharges, simulating lightning. But the interior of the room showed no gain in electricity.
The shielding had forced the negative charges to the outside and the positive charges to the inside, essentially canceling out the electrical current before it could affect anything within the room.
Later, he added a grounding rod and verified that the charge canceled itself out as it traveled around and into the ground.
Today, the principles that Faraday discovered almost 200 years ago are used all across the world to protect people from stray electromagnetic charges. Ever wonder why your cell phone drops calls when you’re in an elevator? It’s a semi-enclosed Faraday cage.
The MRI room in medical facilities, USB cables, coaxial cables (the ones you used to get cable TV from), even cars and airplanes use Faraday shielding to help protect their precious cargo.
And if you want to see one up close and personal, take a look at your microwave. The metal lines in the glass complete the Faraday cage that protects us from electrical discharge and the radiation used to cook your food.
On a smaller scale, metalized static shielding bags protect small electronic components and circuit boards from the much smaller personal EMP’s our bodies generate, which could cause serious damage to these components. Properly sealed ESD boxes and totes, as well as conductive bins use the same principles to protect larger or larger quantities of components.
Of course, while Faraday cages can be ungrounded and even nested to enhance protection, we always recommend taking the proper grounding procedures to protect yourself and your circuitry.
So remember, Faraday cages are not just for “Doomsday Preppers” and science fiction story tropes. They are at work every day to make our world a safer place.
Contact us today for more information; we would love to be your full service, seamless ESD solution provider.