Capacitive Touch screen:

There are 2 types of capacitive touch screens:

Surface capacitive

consists of a uniform conductive coating on a glass panel on which a low voltage is evenly applied fromthe corners

The touch location is measured from the ratio of the current flow from the corners

Projected Capacitive :

Made of a front and back protective glass providing optical and strength enhancement options.

Its middle layer consists of a laminated sensor grid of micro

fine wires and optical enhancement options.

Advantages of Capacitive

High Touch Resolution High Clarity Completely Sealable Disadvantages of Capacitive Must be touched by finger

will not work with any non-conductive input Can be affected by electricity May need re-calibration often.

Surface Acoustic Wave Touch screen Made of a glass overlay with transmitting and receiving piezoelectric transducers for both the X and Y axes. When a touch occurs, the wave is absorbed shortening the echo time it takes to reach the receivers.