A flexible skin-mounted haptic interface for multimodal cutaneous feedback

Haptic feedback systems are a crucial technology for improving immersion in augmented and virtual reality applications, especially those requiring intricate finger motions. However, existing technologies are typically limited by rigid and bulky equipment that can degrade wearability while providing insufficiently nuanced tactile sensations. Here we report a lightweight and flexible finger-worn haptic device that provides controllable and nuanced cutaneous feedback. The device consists of four serpentine shape memory alloy structures in opposing pairs that manipulate a tactor, creating both individual and collective actuation patterns. In total, it can implement 11 distinctive motions for a variety of haptic sensations. In addition, because the device is composed of a soft three-dimensionally printed flexible finger cap structure and elastic cover, it can easily conform to human fingers, enhancing wearability and user comfort. We show that the haptic interface can be used in a variety of virtual and real-world activities.