What does a scientist born in 1791 have to do with your mobile phone? For WaveWall and anti-radiation protection, it’s a lot. Michael Faraday is that scientist. He died in 1867, ten years before the regular telephone was even invented.
Faraday had little in the way of formal education and was notoriously not very good at mathematics. He was originally an apprentice bookbinder. But his discoveries and inventions in electrochemistry and electromagnetism are still used regularly today.
While Faraday was studying the newfangled direct current (DC) electricity it was still mostly an academic phenomenon. He worked on the very beginnings of electric motor technology, which allowed electricity to become the ubiquitous technology it is today.
Faraday pioneered electrolysis, invented an early version of the bunsen burner, made terms like “electrode” and “ion” widespread, and, most importantly for us, established the basis of the electromagnetic field.
This work on the electromagnetic field led to an invention that is still widely used today – the Faraday cage.
The science behind the Faraday cage is simple, once the underlying principles were understood. It’s formed by a mesh of conductive material that cancels out the incoming electrical charge by distributing it around the cage. As long as the gaps within the mesh are smaller than the electromagnetic wavelength of the external energy the inside will remain safe. Sometimes, rather than a mesh a full sheet of material is used, this is called a Faraday shield.
Where do you see Faraday cages in real life?
The mesh you see on the window of your microwave is one. It stops the radiation in the microwave from leaking out. Your cable TV cables probably have one, to stop electromagnetic interference coming in, and stop the TV signal leaking out.
When you lose phone reception in a lift it’s because the metal box that forms the lift is making a Faraday shield and blocking the electromagnetic signal from your phone. Some venues like cinemas are fitted with Faraday cages within the walls to stop people using their phones. Cars and aeroplanes act as Faraday cages – both can be struck by lightning without harming the occupants inside.
Medical equipment like MRI machines are protected by Faraday cages to stop interference from environmental magnetic radiation. Faraday suits can be created to help engineers work safely on electricity lines. The police use Faraday bags to preserve mobile phones and other electrical devices from crime scenes. By putting them in the bag there can be no communication with the phone so it can’t be remotely wiped or interfered with.
This can be used for ill effect – shoplifters can make Faraday bags that stop tagged products from setting off sensors. An Australian man used a crisp packet to stop his work GPS tracker from showing he was playing golf rather than working.
You can easily make a Faraday cage or shield at home
All you need is a conductive metal, like foil. Try wrapping your phone in foil and calling it – there won’t be a connection.
The Faraday cage is the technology behind WaveWall’s anti-radiation mobile phone cases and other radiation-shielding products. A fine weave of metallic fibres in the fabric of the phone case blocks the electromagnetic radiation from your phone. This is important because mobile phone radiation has been linked to cancers, tumours, male infertility, and a host of other health issues.