Patent ID: 8018105

Claim:
A portable communication device, comprising: an electromagnetic vibrator to provide tactile stimuli to a user of the portable communication device, the electromagnetic vibrator including: a housing having a long axis and comprising a track, directed in a first dimension, formed at an inner surface and along the long axis of the housing, a coiling comprising at least one coil turn, oriented in a second dimension essentially perpendicular to the first dimension, coiled around an outer surface of the housing, to receive an electric voltage and form a magnetic field, a permanent magnet assembly to move, guided by a rail associated with the track on or around which said permanent magnet assembly is tightly fitted, responsive to the magnetic field, and a ferrofluid mixture, applied to a sliding surface interface between the track and the permanent magnet assembly, allowing the movement of the permanent magnet assembly in the first dimension in dependence of the electric voltage as supplied to the coiling, to produce the tactile stimuli; and a power source to supply the electric voltage to the coiling.