In a redacted acquisition document obtained by the tech news site 404 Media, the immigration agency proposes entering into a contract to buy “all-in-one” tools from a company called PenLink that will allow agents to “compile, process, and validate billions of daily location signals from hundreds of millions of mobile devices.” The document also mentions payments for services involving “face detection,” “advanced face search,” and a “dark web data feed.”
Aluminum isn’t magnetic. Does it really work for a Faraday cage?
It’s conductive.
While it isn’t magnetic it is useful for shielding electronics. It isn’t as conductive as something like copper tape or conductive tape made to be conductive, but it is still conductive.
The idea is that you want the inside of whatever you’re making NOT to be conductive (duct tape, for example)then another a layer of aluminum with no gaps, then more duct tape, then more aluminum, then more duct tape, it’s done.
Aluminium isn’t the best material for this but it WILL work, and is in fact used to shield lots of electronics components.
I mentioned earlier that it’s conductive, and it’s, but it isn’t a very good conductor, which is one of the reasons that I’ve found when using aluminum two or three layers of it alternating with nonconductive layers tends to be necessary for anything in the -5ghz+ range.
Someone more knowledgeable than me can chime in on the detailed science of how this all works but aluminum and copper both work to attenuate radio signals. They key thing is that anything conductive (copper or aluminum) touching anything conductive (your phone screen or case) will… conduct.
The idea here isn’t making a faraday cage, since at 5ghz you’d need, iirc, a cage with no hole larger than 2mm (good tucking luck with that) but to shield your phone completely from sensing or receiving wireless signals.