Sparse Actuator Array Combined with Inverse Filter for Multitouch Vibrotactile Stimulation

Because vibrations propagate and reverberate, providing precise and distinct vibrotactile stimulation to multiple fingers in contact simultaneously with a touch surface is challenging. Previous research has demonstrated that it is possible to render localised multitouch feedback using piezoelectric actuators. This paper shows that a sparse array of piezoelectric actuators glued to the surface and driven by an inverse filtered signal can overcome those propagation effects and produce undistorted and independent vibrotactile stimuli. Different experiments have been conducted in order to prove that it is possible to realise localised multitouch in any point of a plate. Then an experiment have been realised in order to highlight the impact of the finger on the stimulation signal.