A new wearable fingertip haptic interface for the rendering of virtual shapes and surface features

This work presents the Haptic Thimble, a novel wearable haptic device for surface exploration. The Haptic Thimble combines rendering of surface orientation with fast transient and wide frequency bandwidth tactile cues. Such features allow surface exploration with rich tactile feedback, including reactive contact - no contact transition, rendering of collisions, surface asperities and textures. Above capabilities were obtained through a novel serial kinematics wrapped around the finger, actuated by compact servo motor for orienting the last link, and by a custom voice coil for actuating the plate in contact with the fingerpad. Performance of the voice coil were measured at the bench in static and dynamic conditions, assessing the capability of reproducing generic, wide-bandwidth (0-300 Hz) tactile cues. Overall usability of the Haptic Thimble was explored within a virtual environment involving exploration of virtual surfaces. Finally, a perceptual experiment executed in a teleoperated environment with kinesthetic feedback, showed that the addition of tactile feedback, provided through the Haptic Thimble, significantly improved performance of an exploratory task.