Touch Screen Technology 101

Resistive

The most common and often the least expensive touch screen technology, resistive touch can be found in many PDAs, retail registers, credit card readers, and ATMs. The technology senses touch when a user presses the screen, bringing together two layers of sensing resistive film that determine the location of the touch. Resistive screens are susceptible to damage from sharp objects, repeated use, or excessive force. The clarity and readability of the display is also compromised because the layers used to register touch reduce transparency.

Capacitive

The Apple iPhone is an impressive advance in the use of capacitive touch and popularized multi-touch commands for the general public. Capacitive touch screens come in two flavors: surface capacitive and projected capacitive. Capacitive touch panels sense the change in the alternating current applied to a conductive layer in the panel when it is touched by a finger. Capacitive screens are longer-lasting than resistive screens, but these screens can also be compromised by moisture on the touch surface. Another drawback is the screens cannot sense a touch if the user is wearing a glove. For the iPhone, Apple contracted the screens to the German company, Balda.