I know how our touch screens work by sensing changes in voltage with capacitors, and then pinpointing our fingers location. But recently I was playing with a ceramic magnet on my phone.

As I took the magnet across the screen, the screen sensed the change in voltage and moved the screen!

Check out this video. In the video, I show the ceramic magnet moving the touch screen. And if you noticed, when I remove my finger from the magnet, the magnet acts like a finger not touching the screen.

Now I wonder if the movement of the magnet induces current in the capacitors of the touchscreen like a coil of wire. I also wonder, if the static charges stuck on the magnet are flinging to the screen, thus creating a change in voltage. Afterall, ceramic is a good insulator.

What is causing the screen to move when using the ceramic magnet?

  • $\begingroup$ Ceramic is also a good dielectric. Your finger is a pretty good insulator, just like the ceramic... $\endgroup$ – Jon Custer Jun 28 '17 at 20:32

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