Wearable haptics for virtual reality and beyond

Research has increasingly focused on wearable systems that provide informative haptic sensations to the hands, enhancing user interaction in virtual reality (VR) and augmented reality (AR) environments. Concurrently, the evolution of VR visors in terms of wearability, quality of the visual immersion and immediateness of bare-hand interaction poses both opportunities and challenges for haptic systems, which must match these visors in usability, hand-tracking compliance and quality of experience. Designing haptic devices involves trade-offs between the dimensions and quality of feedback, often falling short of the richness and complexity of natural haptic sensations. Recent studies have explored various actuating methods and haptic prototypes to enhance the wearability and feedback richness of haptic devices. Notably, the development of soft interfaces actuated by diverse principles has emerged as a key trend. Moreover, beyond simulating physical interaction, haptic technologies can provide high-level information for various applications, including posture correction, navigation and remote control of humanoid robots. In this Review, we provide an overview of wearable haptics for VR applications, introducing principles of haptic rendering and the relationship between stimulus modalities and actuating solutions. We discuss emerging actuating methods and wearable device designs, examining their experimental applications in innovative scenarios of VR and beyond. This Review provides an overview of haptic perception principles and rendering strategies developed for wearable haptics solutions. The Review then revises the scientific literature regarding emerging actuators and device prototypes, and their applications in innovative scenarios focused on, but not limited to, virtual reality (VR).