A touch sensitive navigational surface functions as a user interface to a communication device such as a cellular telephone. An electromechanical dielectric (EMD) film coextensive with at least a portion of the surface of the cover of the device selectively functions as a sensor, microphone or speaker. The EMD film is placed behind a display to provide a user interface touch sensitive screen capable of sensing the direction of touching. At least a portion of the EMD film functions as a fingerprint recognition system to provide security means for controlling access and limiting call completion to an authorized user.