Origins

• The history of touch screen technology began in 1971, with Sam Hurst's invention the "Elograph." It wasn't transparent, but it was an important step toward the touch screens we have today. Hurst went on to found Elographics, now known as Elo TouchSystems. In 1974, he created the first "true" touch screen using resistive technology.
  
  

Types

• A resistive touch screen panel works by converting pressure on the screen to an electric connection between two thin layers of metal. A processor inside the device can then interpret the pressure. Another type of touch screen technology is known as surface acoustic wave (SAW). Ultrasonic waves surround the touch panel and detect when you touch the screen, and then the processor interprets the data. These types of systems aren't very sturdy, so weather or surface contaminants can make them stop working.
  
  

Capacitive Sensors

• Capacitive sensing is a different form of touch screen technology. In this kind of system, glass is coated with a transparent material that enhances conductivity. Because human bodies carry an electric charge, touching the screen changes the electrostatic field, a measurement that the processor interprets. Various types of technology are used to interpret a touch. These methods include surface capacitance, in which only one side of the glass is coated with the conductive material, and Projected Capacitive Touch technology, which works with a finely etched grid system. This system is used in smart phones and some types of kiosks.
  
  

Use in Kiosks

• Touch screens are used in public information kiosks, ATMs, ticket vending machines, post offices and at many grocery stores. The technology has become so pervasive that even toy ATMs for children use touch screen technology.
  
  

Consumer Electronics

• Consumer electronics such as the iPhone, iTouch, Nintendo DS, personal digital assistants and even some personal computers use touch screen technology.