Possibly you’ve some idea about Faraday cage and in fact, you might have spent time in a Faraday Cage. It’s this Faraday cage that keeps you safe in the aircraft or car during a thunderstorm. Faraday Cage, first invented in…
Possibly you’ve some idea about Faraday cage and in fact, you might have spent time in a Faraday Cage. It’s this Faraday cage that keeps you safe in the aircraft or car during a thunderstorm. Faraday Cage, first invented in 1836 by esteemed English scientist Michael Faraday, is a simple yet very powerful technological development. Over the years, it has become omnipresent in our modern technological world.
As you might know, every electrical device is vulnerable to electromagnetic noise. The electromagnetic disturbances, also known as EMI hinders the functionality and efficiency of all electronics. If not controlled, the Electromagnetic interference (EMI) and radio frequency interference (RFI) present around us can result in device failure and pose other risks also. To prevent these issues, Faraday cages come in. Now let’s take a quick look at what Faraday cage is and why it’s used.
What is a Faraday Cage?
A Faraday cage, also known as a Faraday Shield, is a conductive enclosure that protects the inside from external electric fields and external electromagnetic radiation. This cage is used to shield things from electromagnetic fields– both static and non-static.
Michael Faraday in his studies and experiments discovered that when electrical charges strike the outside of the cage, it does not affect the inside. It was found that an electrical conductor (like a metal cage) when charged appeared to exhibit that charge on its surface only and not inside. In this experiment, Michael Faraday lined a room in metal foil and passed high-voltage discharges from an electrostatic generator to strike the outside of the room. With the help of an electroscope (a device that detects electrical charges), he found that the room was completely devoid of electrical charge.
A Faraday Cage can be made from a continuous covering of conductive material or a fine mesh of conductive material. Whether made of chain-link fences or metallic meshes, these cages take electrostatic charges and distribute them around the exterior of the cage.
What are Faraday Cages used for?
Faraday Cages simply act as a shield to anything within them and have become quite handy in a variety of applications. At present, Faraday cages are very popular and widely used in our everyday lives. For instance, automobiles and airplanes have fuselages that act as Faraday Cages for their occupants. This protects you in case lightning strikes the aircraft or car. Other examples include a microwave oven and MRI scanning rooms. Unlike other applications, microwave oven keeps the microwave radiation within the oven. The basic idea is that any noise created inside the cage is prevented from escaping to the outside world. And this is how a microwave oven works. On the other hand, the MRI scanning rooms are built like this to prevent external radio frequency signals from being added to the data from the MRI machine. The Faraday cage is also used by politicians and high-level executives who need to block the eavesdropping devices. To maintain the secrecy of the conversations regarding sensitive matters, meetings are often held in special Faraday cage design shielded rooms.