A Faraday cage (or Faraday shield), named after Michael Faraday, is a device used as a shield against electromagnetic radiation. Faraday cages can be made by joining together a cover containing conductors, or a mesh of similar material. This creates a shielding effect on any object in the cage and protects the object from radiation. This cage effect can be enhanced by placing both conducting and non-conducting layers – this creates a cage within the cage within the cage, providing additional protection without the need for special materials. As complicated as it sounds, you can make your own Faraday cage out of aluminum foil. You can also make them in a larger size using a steel trash can.
Step
Method 1 of 2: Making a Faraday Cage out of Aluminum Paper
Step 1. Wrap the electronic device in a plastic layer
Wrap the device in a plastic bag. This creates a barrier between the device and the aluminum layer containing the conductor. It can also be a waterproof layer for added protection.
You can wrap the object inside the shirt to help prevent the edges from puncturing the plastic and/or aluminum foil, although this isn't necessary
Step 2. Cover each side of the device in aluminum foil
Aluminum foil serves as a conductor layer. Do not leave any tears or gaps in the paper. Use your hands to shape the paper around the entire device. This is the simplest Faraday cage and will protect the device from everyday low-power electromagnetic radiation such as bluetooth, cell phone signals, etc. For added protection, use more layers of plastic and foil.
Step 3. Tin foil is used as the conductor layer
Its metallic content will allow radiation to pass through its surface but not through it.
Step 4. Alternately coat with plastic and aluminum foil
Cover each side of the device with at least three layers of foil. Protection can be maximized by adding a layer of plastic between each layer of foil. This creates a layer of both conductor and non-conducting materials and protects the device from harmful electromagnetic radiation.
- The Faraday cage is designed to protect the device from EMP (electromagnetic voltage) explosions. This is a burst of high-intensity radiation emanating from a naturally powerful weapon or source (eg the sun).
- Faraday cages can also be used to block cell phone or radio signal reception, or prevent your expensive car from being stolen by protecting its keyfob (keyless door opening). In this case, you'll need fewer layers because the radiation is much weaker than an EMP blast.
- Adding an adhesive such as glue between each layer will make the Faraday cage sturdier and more permanent, but will be more difficult to remove.
Method 2 of 2: Building a Larger Faraday Cage
Step 1. Look for a receptacle made of conductors
Stainless steel trash cans with tight-fitting lids work great. You can also use other metal containers or boxes. It serves as the first line of defense against electromagnetic radiation.
Step 2. Line the inside of the container with a plastic bag
After selecting a trash can or other container, line the inside with a plastic bag. This protects the device from coming into contact with the surface of the trash can which is made of conductors, and also provides protection against flooding.
- For added insulation, you can line the inside of the can with cardboard before applying the plastic layer.
- You can add a layer of foil and an additional plastic bag inside to increase the effectiveness of the Faraday cage. More layers will make the cage more effective, even if the layers are thin.
Step 3. Place the device inside
After lining the trash can, place the device in the bin. It is best to wrap the devices individually in a small Faraday cage (like an aluminum foil Faraday cage). You can buy Faraday pouches and place items in the pouch. The trash can will serve as an additional layer of protection.
Once the device is inside, you can attach the lid using glue or screws to make the cage more sturdy. It's also a good idea to tie the cage to a block of wood or nail it to the wall using metal straps to make the cage a permanent fixture
Tips
- Do not attempt to use appliances such as refrigerators or microwaves as Faraday cages. These tools do not provide enough protection.
- You can use rubber instead of plastic to create an insulating layer.
- Conductor layers can be made of other materials that contain conductors such as copper, although they are more expensive.
