The official Symbian blog as just published a video taken at SEE 2010, with Terence Warmbier of the Immersion Corporation. This is the company responsible for the haptic feedback hardware found in every Symbian device. Immersion is pushing haptic technology to allow users to discern material textures and spatial sensation, from just a tap of a screen. This technology is already applied to user interfaces and games, but Warmbier also spoke about using haptic ringtones to allow the user to feel who is calling them. Click through to see the video.
In the video, Warmbier talks about the technology behind haptics, and how different sensations are created by changing frequency, duration and intensity of vibration. He also talks about the various motor technologies, going from "Piezoelectric Ceramic" actuators (materials which vibrate when electrically charged), "Linear Resonant" actuators which behave in the same way as loudspeaker coils (i.e. a magnetic mass is driven by a coiled wire), and a range of "Eccentric Rotating Mass" (ERM) actuators (asymmetric weights which are spun by a motor).
David Gilson for All About Symbian, 18th November 2010