While You Were Gone, Daily

Capacitive Touchscreens, How Do They Work?

I made the exciting discovery today that, along with this ridiculous contraption, and delicious Korean sausages, you can also use a pack of Wrigley’s Extra chewing gum (Cool Breeze flavour) as a makeshift iPhone stylus*. And it occurred to me that, other than knowing it has nothing to do with pressure, I had no idea how capacitive touchscreens, such as those sported by the iPhone and iPad, work.

So I looked it up on Wikipedia. It goes roughly like this: The screen of an iPhone is made of glass, covered by a veeery thin layer of a material which conducts electricity. You know what else conducts electricity? Your finger. Or delicious Korean sausage. Or the metallic end of a pack of Cool Breeze flavour Wrigley’s chewing gum.

Now when two things that conduct electricity touch, it creates a distortion in the electrostatic field surrounding them. You know how excited you got when that pretty girl you liked in high school touched you on the arm? It is exactly like that.

You can measure this distortion with swanky electronic jiggery pokery. Somewhere along the line capacitance is involved (…your delicious Korean finger touching the screen becomes a capacitor?) But to be honest, this is already more technical detail than I was looking for, so this is as good as you’re going to get.

Long story short: gaffer tape a large ball bearing to the end of your mittens and you won’t have to take them off to play on your iPad this winter. Science!

This is all paraphrased directly from Wikipedia’s article on touchscreens, so if it’s wrong it’s because Wikipedia is literally written by monkeys.

* On the train. Where all the best scientific discoveries are made.