Skin-Integrated Soft Wearable XR Interfaces for Seamless and Realistic User Experience.

Extended reality (XR) is an emerging field that connects the physical and digital worlds, enabling communication that transcends time and space. Commercial XR devices have been developed to support such experiences, but they are limited to specific sensations, mainly vibrational cues. Furthermore, these devices are realized mainly in rigid form factors, requiring external controllers or equipment, which hinders intuitive interaction and causes a mismatch with natural body movements. In this regard, skin-integrated human-machine interfaces with wearable electronics have played an important role in intuitive and immersive interaction in the XR environment, facilitating highly authentic sensory reconstruction and perception. Novel innovations in materials and structural design have enabled a wider range of sensory modalities and miniaturization, overcoming the limitations of conventional rigid XR systems. In this article, we thoroughly review human perception mechanisms to replicate hyper-realistic sensations. Then, we deal with the design and functionality for sensory feedback and input, specifically tailored for XR applications. In addition, we discuss precise system-level integration for untethered XR devices, alongside the role of artificial intelligence in real-time processing and rapid sensation conversion through predictive algorithms. Finally, we introduce promising XR applications and conclude with the challenges and prospects of future XR technologies.