How does a touchscreen know exactly where your finger is pressing?
The Electric Touch
How does a touchscreen know exactly where your finger is pressing?
You tap a glass screen, and somehow it knows. Not "somewhere near there" — it knows, down to the pixel, exactly where your fingertip landed. There's no tiny person inside watching for your finger. So how does a sheet of glass feel a touch?
Here's the secret most phones use: your finger is a little bit electric. Your body is mostly water and salt, and that makes you a decent conductor — electricity can travel through you. The screen doesn't care that you're a person. It just notices that something conductive showed up.
