When you press down on the touch screen, contact is made between the grid on the glass and the grid on the film. The voltage of the circuit is measured, and the X and Y coordinates of the touch position is calculated based on the amount of resistance at the point of contact.

This analog voltage is processed by analog-to-digital converters (ADC) to create a digital signal that the device's controller can use as an input signal from the user.

What's so special about Gorilla Glass?

Many vendors are quick to trumpet the use of Corning's Gorilla Glass in their products. The glass is used as a protective outer layer for many devices, from smartphones to large flat panel televisions. But what makes Gorilla Glass different?

The answer lies in the composition of the glass itself. Most display glass is an alumina silicate formulation, which is made up of aluminum, silicon, and oxygen. The glass also contains sodium ions spread throughout the material. And this is where the difference starts.