Evaluation of Ultrasound Haptics as a Supplementary Feedback Cue for Grasping in Virtual Environments

This paper presents an evaluation of ultrasound mid-air hap tics as a supplementary feedback cue for grasping and lifting virtual objects in Virtual Reality (VR). We present a user study with 27 participants and evaluate 6 different object sizes ranging from 40 mm to 100 mm. We compare three supplementary feedback cues in VR; mid-air haptics, visual feedback (glow effect) and no supplementary feedback. We report on precision metrics (time to completion, grasp aperture and grasp accuracy) and interaction metrics (post-test questionnaire, observations and feedback) to understand general trends and preferences. The results showed an overall preference for visual cues for bigger objects (> 60 mm) while ultrasound mid-air haptics were preferred for small virtual targets 50 mm).