A system for providing haptic feedback to a user, the system at least comprising: an electronic device at least comprising a touch-sensitive display screen having a touchable surface coated with a transparent film able to provide a variable surface friction to the touchable surface in response to an externally applied electromagnetic field; and a magnetic loop actuator for applying the electromagnetic field to the film to vary the surface friction of the touchable surface; characterized in that: the magnetic loop actuator is external to the electronic device, and in that the system further comprises: a separable electrical connector between the electronic device and the magnetic loop actuator; a driver module to drive the magnetic loop actuator to generate the electromagnetic field; and a triggering module to trigger the driver module; wherein the driver module and the triggering module are external to the electronic device; and wherein the electronic device is installed with an application configured to receive a user input from the touch-sensitive display screen, to determine a haptic output to the user in response thereto, and to output a control signal to the triggering module to vary the surface friction of the touchable surface according to the haptic output thus determined. an electronic device at least comprising a touch-sensitive display screen having a touchable surface coated with a transparent film able to provide a variable surface friction to the touchable surface in response to an externally applied electromagnetic field; and a magnetic loop actuator for applying the electromagnetic field to the film to vary the surface friction of the touchable surface; characterized in that: the magnetic loop actuator is external to the electronic device, and in that the system further comprises: a separable electrical connector between the electronic device and the magnetic loop actuator; a driver module to drive the magnetic loop actuator to generate the electromagnetic field; and a triggering module to trigger the driver module; wherein the driver module and the triggering module are external to the electronic device; and wherein the electronic device is installed with an application configured to receive a user input from the touch-sensitive display screen, to determine a haptic output to the user in response thereto, and to output a control signal to the triggering module to vary the surface friction of the touchable surface according to the haptic output thus determined. a separable electrical connector between the electronic device and the magnetic loop actuator; a driver module to drive the magnetic loop actuator to generate the electromagnetic field; and a triggering module to trigger the driver module; wherein the driver module and the triggering module are external to the electronic device; and wherein the electronic device is installed with an application configured to receive a user input from the touch-sensitive display screen, to determine a haptic output to the user in response thereto, and to output a control signal to the triggering module to vary the surface friction of the touchable surface according to the haptic output thus determined.