Emulating Textures Using Vibrotactile Technology: HaptTech System and its Adaptation to a Commercial Kinesthetic Interface

This article presents the development and testing of a tactile interface prototype, HaptTech, that applies vibrotactile stimulation pat-terns to the fingertip, as well as an analysis of its performance when coupled to the commercial kinesthetic interface Novint Falcon. Its applicability in digital entertainment expects to improve the level of immersion into virtual reality scenarios. In the first experiment, a group of 75 subjects compared three different vibration stimuli that emulated different textures. They evaluated the stimuli on a 1 to 10 scale, where 1 means ‘non-perceivable differences’ and 10 means ‘entirely differentiable’. The obtained mean values were 9 (textures 1 and 3), 8,29 (textures 1 and 2), and 7,43 (textures 2 and 3), indicating HaptTech’s capability to reproduce differentiable stimuli. In the second experiment, 31 subjects evaluated the coupling between HaptTech and Novint Falcon. They perceived differences when the HaptTech system was activated in the context of a comparison between kinesthetic and vibrotactile plus kinesthetic stimuli. In the third experiment, the subjects evaluated the similarity between the perceived stimuli on the hand and a visualized texture pattern in a virtual environment. The resulting median values were 8, 8, and 9 for textures 1, 2, and 3, respectively, which demonstrate that the subjects perceived a high correspondence for each one.