Touch screens

Touch screens are in our everyday lives whether you like them or not.  Whether its on your new Iphone or if its at the supermarket checkout, touch screens are everywhere and always in use.  However, just a decade ago phones with touch screens and tablets were the "new incredible technology" that everyone marveled at.  Most people though never actually bothered to find out how these touch screens work and now most people use them with no clue how they work.  There are multiple types of touch screens out there however the two most common are the capacitive and resistive ones.
Resistive touch screens are the type of touch screen that you see at all banks and supermarkets.  They generally appear pretty cheap and are often frustrating because they don't always work perfectly.  These touch screens work with conductive sheet with an electrical current that is always running below the screen.  When you press on the screen, it pushes the layer with the conductive sheet to another sheet that is resistive with a electrical current and when those two go into contact, the current changes at that point and the computer then reacts based on where the current changed.  This has a major flaw however because since it measures where you click based on current, you can not click with more than one finger at a time.


Capacitive touch screens are the type that can be found in your average samsung or Iphone.  These work by reading electrical charge instead of resistance.  This means that when you touch the screen an electrical charge is sent to the phone where you touched it which causes a voltage drop.  This means that you can use anything with a charge to operate these touch screens.