Perception of Ultrasound Haptic Focal Point Motion

Ultrasound haptic patterns can be rendered by continuously moving an ultrasonic focal point. It is not known how this focal point motion affects haptic perception. We present two psychophysical experiments investigating the perception of an ultrasound haptic focal point moving along a circular path. Our first experiment finds that a sensation of motion is perceived at speeds up to 17 rev s(-1), similar to the 'flutter' sensation. Our second experiment found a linear relationship between movement speed and perceived intensity up to this speed. Our findings give new insight into ultrasound haptic perception and give designers empirical evidence to inform contactless haptic feedback design.