A Faraday cage, also known as a Faraday shield, is an enclosure made of conductive material that blocks electromagnetic fields. It can be formed by a continuous covering of conductive material or by a mesh of such materials. Faraday cages are named after Michael Faraday, who invented them in 1836.
The cage operates because an external electrical field causes the electric charges within the cages conducting material to be distributed so that they cancel the fields effect in the cages interior. This phenomenon is used to protect sensitive electronic equipment, such as RF receivers, from external radio frequency interference (RFI) during testing or alignment of the device. Faraday cages can also be used to prevent external electromagnetic interference (EMI, or noise) from interfering with neural recordings.
Faraday cages can be made of any material that can conduct electricity, such as wire mesh or metal plates. The materials used to make a cage depend on the length of waves youre trying to keep out and to what degree you need to exclude them.
Some practical applications of Faraday cages include:
- Protecting sensitive electronic equipment from external radio frequency interference (RFI) during testing or alignment of the device
- Preventing external electromagnetic interference (EMI, or noise) from interfering with neural recordings
- Providing emission security for computers as part of the U.S. and NATO Tempest standards and similar standards in other countries
- Preventing remote wiping and alteration of criminal digital evidence in digital forensics
- Shielding whats inside from surrounding electromagnetic radiation (EM) in scientific experiments
In summary, a Faraday cage is an enclosure made of conductive material that blocks electromagnetic fields and is used to protect sensitive electronic equipment and scientific experiments from external interference.
