FingerWrap: A High-Density Finger-Enveloping Tactile Display.

Touch enables humans to recognize the location, motion, shape, and properties of contacted objects in the real world through mechanoreceptors distributed widely across the skin. However, existing tactile displays typically stimulate only the ventral surfaces of the fingers and hands, limiting the range and richness of touch-based interactions in interactive systems. Here, we present FingerWrap, a high-density pneumatic pin-array display that wraps around the finger and activates the widely distributed mechanoreceptors. FingerWrap uses 337 pins arranged at 13 pins/cm$^{2}$, which cover the ventral, dorsal, and lateral surfaces of the finger up to 45 mm from the fingertip, enabling precise spatiotemporal stimulation across continuous regions of the finger skin. Across six perceptual experiments, we show that FingerWrap can provide tactile experiences that ventral-only displays cannot achieve. These include the discrimination of stimulus locations and motion trajectories across multiple regions of the finger skin, the recognition of three-dimensional shape features, and the perception of realistic resistance when the finger is immersed in virtual liquids. This display, which enables a rich and realistic touch experience, could serve as a platform for exploring novel tactile interactions and basic scientific research.