Midair Haptic Pursuit

In human vision, smooth pursuit eye movement is the basic ability to visually follow a moving object by keeping it at the sight center. In this study, we validate that a human hand has a similar ability to track a midair haptic stimulus, i.e., a human palm exposed to a point vibration by a noncontact ultrasound tactile display can follow the continuous movement of the stimulation point. The experimental results show that the trackable velocity limit is 10 cm/s for motion parallel to the palm, when the initial velocity is zero. This ability of motion tracking by hand can be applied to haptic guidance for visually impaired people or for evacuation navigation, where no devices are needed to be equipped by users.