A sample from a longer piece about the electronics behind touch screens:
by Brooke Reedlunn
“Are you reading this article on a touch screen…right…now!?! Maybe not, but chances are that you’ve used a touch screen before on a phone, on a checkout screen at the store, or on tablet. It’s so easy to use your finger to move things on a screen that even a toddler can do it. But the engineering that goes into making them is not so simple at all. Have you ever stopped to wonder, how your finger and the computer work together? Well I did, and what I found out might surprise you!
YOU are a part of the computer’s circuit when you use a touch screen because your body can conduct electricity. You might be thinking, “WHAT!?! Touch screens don’t zap me with electricity!” You are mostly right but in order to understand more let’s back up and figure out what really happens. A circuit is made of wires that are like a road on which electrons can travel. The battery or power source creates the energy or voltage that makes electrons get excited and move through the circuit. The don’t actually get excited like you do at recess but they do start moving faster in kind of the same way.”