How do touch screens work? - Electronics

How do touch screens work?

- A touch screen is a surface, usually glass, which signals the microcontroller about the position of the surface being touched. It is a type of input device in which no other external pointing device is required.
Basically, there are two types of touch screens used in everyday life.

-Resistive touch: These type of screens are constructed of multiple layers. There are two electrically resistive layers that have a thin gap between them. Whenever voltage is passed through a layer they get detected by the other layer. These types of screens are highly resistant to liquid and are cheap to manufacture. On the downside these screens do not produce enough contrast and may get damaged by sharp objects. They do not support multi touch.

-Capacitive touch: These types of screens do not contain various layers instead they have a solid glass which is coated with some form of a conductor. It works on the principle of electric fields. The capacitive type of touch screens can support multiple touches in one go, something that is not possible in resistive screens.