Combination of Mechanical and Electrical Stimulation for an Intense and Realistic Tactile Sensation

Naturalistic tactile sensations can be elicited by mechanical stimuli because mechanical stimulations reproduce natural physical phenomena. However, a mechanical stimulation that is too strong may cause injury. Although electrical stimulation can elicit strong tactile sensations without damaging the skin, it is inferior in terms of naturalness. We propose and validate a haptic method for presenting naturalistic and intense sensations by combining electrical and mechanical stimulation. We validate the proposed method by verifying whether both enhancement of the subjective strength of mechanical stimulation through electrical stimulation and elimination of the bizarre sensation of electrical stimulation through mechanical stimulation can be achieved. We find that the proposed method increases subjective intensity by 25% on average across participants compared with mechanical stimulus alone and decreases the bizarre sensation compared with the presentation of the electrical stimulus alone. The method can be used to enhance the experience of virtual-reality content but has room for improvement especially in terms of intensity enhancement.