ExtEdge: Haptic Augmentation of Visual Experiences of a Smartphone by Electro-Tactile Sensation Through the Edges

We present ExtEdge, a design and method for augmenting the visual experiences of a smartphone using electro-tactile stimulation. We aim to explore new interactions through tactile augmentation of visual information, such as virtual characters, at the edges of the screen. ExtEdge presents distributed tactile sensations through electrical stimulations from electrode arrays mounted on both edges of the smartphone. This distributed tactile stimulus fits the image at the edges of the screen and provides a more realistic presentation. We first investigated two-point discrimination thresholds in the contact areas of the grasp-middle finger, ring finger, thumb, and thenar eminence-as a performance evaluation of the distributed tactile presentation and found that our design was adequate. We then conducted a user study with some application scenarios and confirmed that ExtEdge enriches visual information.