Traveling vibrotactile wave - a new vibrotactile rendering method for mobile devices

The use of a vibration motor is recently receiving attention for haptic interaction with mobile devices. An important aspect of haptic interaction using the vibration motor in mobile devices is to compute and to generate vibrotactile information in response to user's input. Although a vibration motor with low power consumption can be easily inserted into mobile devices, the vibration motor can hardly generate sufficient vibrotactile sensation if we do not consider vibrotactile rendering. This paper presents a vibrotactile rendering method which makes a traveling vibration along the surface of a mobile device. By controlling the vibrations generated by two motors, we can specify the location where the overlapping of two waves occurs and furthermore, can generate the sensation of flowing vibration by continuously changing the overlapping point by adjusting the timing of motor actuation. A ball rolling game is constructed as a test bed for the proposed vibration rendering method. We conduct experiments to evaluate if the proposed vibrotactile rendering method can haptically display not only collision but also the ball's rolling. The experimental results clearly show the effectiveness and the feasibility of the proposed vibrotactile rendering method.