Surface capacitive touchscreens sense the conductivity of the finger or a conductive stylus via 4 electrodes placed in the corners of the screen.
When a touch is initiated, an electrical current starts flowing from the corners to the finger or stylus and the exact location of the touch can be registered.
SCT technology is a proven and reliable solution. However, it does not allow multi-touch functionality, plus the screen can be more susceptible to a loss of performance due to scratches on the capacitive coating than the more advanced Projected Capacitive Technology.
