How do touchscreen compatible materials work?

Submitted ⁨⁨3⁩ ⁨months⁩ ago⁩ by ⁨strawberry@kbin.run⁩ to ⁨nostupidquestions@lemmy.world⁩

https://kbin.run/m/nostupidquestions@lemmy.world/t/613904

got curious when I realized my bandaid was somehow touchscreen compatible, despite seemingly just being a piece of cloth. nitrile gloves work, and I've even got relatively thick work gloves that work.

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HootinNHollerin@lemmy.world ⁨3⁩ ⁨months⁩ ago
Capacitive I believe. The charge in your finger is being sensed

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bane_killgrind@slrpnk.net ⁨3⁩ ⁨months⁩ ago
“Glove thickness is usually given in the unit mils, which is equal to one one-thousandth of an inch”

7 thousandths of an inch is well within the thickness that generates a measureable capacitance.

Hoot is not really correct, it’s not the charge it your body. It’s the difference in charge across an insulator sinking some amount of farad energy, and that change in sink capacity being measured.

You could make your own capacitor with some insulating resin paint and a couple metal plates.

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Kolanaki@yiffit.net ⁨3⁩ ⁨months⁩ ago
They just let the natural electrical signal of your body pass through unimpeded usually by being made of or having conductive material woven through them.

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j4k3@lemmy.world ⁨3⁩ ⁨months⁩ ago
The modern version is based on capacitive touch. The older versions with the stylus required were mostly resistive where there were two layer matrices in X and Y directions and the crossed resistive connections are calculated. There was also an in between rarer version of the touch screen that was optically driven. These require a special stylus that technically does not need to make physical contact to work, (it was crap compared to capacitive touch).

If you were around back in the day of rabbit ears and television or had a radio that would only work well when you were in just the right spot in the room while you held your tongue at the right angle, that is basically the same principal of capacitive touch. Your body’s electrical properties are more pronounced at higher frequencies and this is effect is used to detect where changes are happening on an X/Y matrix.

The actually connections are a tin oxide coating on the glass that is conductive but so thin that it is optically clear. Ben on Applied Science on YT has shared some videos where he uses this same coating technique for various projects.

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