A novel micro-vibration actuator and the presentation of tactile sensations

A novel micro-vibration actuator using a shape-memory alloy for the presentation of various tactile sensations to a human skin is introduced in this paper. The authors paid attention to the characteristics of a shape-memory alloy formed into a thread, which changes its length according to its temperature, and developed a vibration-generating actuator electrically driven by periodic signals generated by current control circuits. For the tactile information transmission to a human body, the human higher-level perception such as the phantom sensation and the apparent movement of the tactility is employed in consideration of presenting novel tactile sensations. By coupling the actuators as a pair, an information transmission is realized for presenting novel tactile sensations to a user. The information transmission was tested by changing various conditions of electric signals to drive actuators, and was evaluated by questionnaires. Several users reported that they perceived a novel rubbing sensation given by the apparent movement, and we further experimented the presentation of the sensation in detail to be used as a tactile display for the information transmission through our body.