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Comment by superkuh | Hacker News Reader

This article is oddly-specific about the possible use cases for an electrically switchable conductive film. Somehow I doubt that S21 attenuation in the non-conductive mode is going to be low enough that anyone is going to want to put this around their radio antennas.

Unfortunately I can't tell because sci-hub hasn't added new articles to their database since the case against it in India started in 2020 and this is locked behind a paywall.

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My immediate (i.e. unconsidered) thought is a solid state zone plate (like a radio version of a Fresnel lens) which can be used for adjustable focusing or steering of incident radio waves.

MU-MIMO does what you describe and is implemented in WiFi and 3GPP (LTE/5G) standards. Leads to significant gains in spectral efficiency too.

It does seem a little weird, yeah. I mean, the researchers are from Drexel University. I would've figured that the applications that they would be most interested in would be fast optical switching and MEMS devices - whereas in this press release it seems like they're trying to "sex" up the findings by suggesting that they can be used to make a Romulan cloaking device for macroscopic antennas.

This article might have suffered at the hands of an overenthusiastic PR team.

You wouldn't put shielding around an antenna, that kind of defeats the purpose of being an antenna.

The thing about circuits that work at GHz frequencies, is that the wavelengths are small enough that practically any part of your circuit can absorb EM, so it would be handy if the enclosure had this shielding effect.

A copper foil (or tin shield box) would be far better.

A kind soul emailed me the full text paper. Apparently the transition from conductive to non-conductive via oxidation is irreversible. So this would be a special coating applied to products to protect them from EMI during supplychain/shipping but not afterwards? Seems niche. But it is cool.

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