1 HN user recommended this explainer1 month2017–2020score 1
Years with an HN recommendation, 2007–2026
HN recommends it as an informative explanation of what those tags are, especially in threads about implants and RFID.
Applied Science explains how retail anti-theft tags work. A tiny magnetostrictive strip acts as a mechanical oscillator excited by a magnetic field, and magnetizing or demagnetizing it arms or disarms the tag.
“here's an interesting and informative video from Applied Science on how these tags work” (HN, 2017)
Right, which is precisely why automatic doors are completely irrelevant. On a related note, here's an interesting and informative video from Applied Science on how these tags work: [this video]
Explains how magnetostrictive anti-theft tags work
Those RFID tags are pretty minimal though. Basically just a thin trace antenna and silicon die directly molded into plastic. [this video] I still agree that it's amazing that our society can make functional structures with feature sizes in the nm/µm ranges so cheaply that we can afford to throw them away.
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