Nanowire‐Based Soft Wearable Human–Machine Interfaces for Future Virtual and Augmented Reality Applications

A virtual world has now become a reality as augmented reality (AR) and virtual reality (VR) technology become commercially available. Similar to how humans interact with the physical world, AR and VR systems rely on human–machine interface (HMI) sensors to interact with the virtual world. Currently, this is achieved via state of‐the‐art wearable visual and auditory tools that are rigid, bulky, and burdensome, thereby causing discomfort during practical application. To this end, a skin sensory interface has the potential to serve as the next‐generation AR/VR technology because skin‐like wearable sensors have advantages in that they can be ultrathin, ultra‐soft, conformal, and imperceptible, which provides the ultimate comfort and immersive experience for users. In this progress report, nanowire‐based soft wearable HMI sensors including acoustic, strain, pressure sensors, and physiological sensors are reviewed that may be adopted as skin sensory inputs in future AR/VR systems. Further, nanowire‐based soft contact lenses, haptic force, and thermal and vibration actuators are covered as potential means of feedback for future AR/VR systems. Considering the possible effects of the virtual world on human health, skin‐like wearable artery pulses, glucose, and lactate sensors are also described, which may enable imperceptible health monitoring during future AR/VR practices. Future augmented reality and virtual reality systems may be imperceptible like wearable epidermal skins. They may have an electronic tattoo for motion tracking and haptic feedback, a skin‐like electroencephalogram patch for brain–machine interaction, a contact‐lens display for visual feedback, an ultrathin acoustic sensor for voice recognition, and an epidermal biometrical sensor for continuously monitoring human health in the virtual world.