beth (defunct)

there's two main types of touch screens: capacitive and resistive touch screens. resistive touch screens work by having your finger push a conductor down onto thingy that completes a circuit. styluses for it can be literally anything that is capable of pushing. phones styluses tend to not work since they're squishy instead of solid. capacitive touch screens are a fair bit more complicated, so i really recommend reading the wikipedia article i linked, but your finger kinda conducts a current which completes the circuit. it doesn't work with ds styluses since those are just plastic and don't really help with circuits. there's also however drawing tablets work but those are different since the stylus there uses magnetic fields or something it's wild.

edit: got ninja'd by someone who wrote a better post than i did lol