Whole-Hand Haptics for Mid-air Buttons

Mid-air buttons are currently slow and error-prone. One reason is that their haptic feedback are attempts at replicating physical button feedback instead of being designed specifically for interaction in mid air. We present an approach to haptics for mid-air buttons that extends the feedback beyond the fingertip. Our approach is inspired by recent findings that show how skin vibrations from fingertip presses extend to the whole hand. We apply the haptic feedback across the whole hand to simulate the pull-up effect that triggers users to withdraw their finger upon button activation. We conduct a user study with two tasks to evaluate the whole-hand feedback and compare it with prior work. Our results show that the whole-hand haptic feedback reduces the overall button press duration and allows for more successful button activations compared to the localized haptic feedback. We discuss the reasons behind the improved performance and further steps to improve mid-air presses.