Recent advances in multimodal skin-like wearable sensors

Wearable sensors capable of simultaneous monitoring of multiple physiological markers have the potential to dramatically reduce healthcare cost through early detection of diseases and accelerating rehabilitation processes. These skin-like sensors can deliver significant benefits thanks to their ability to continuously track various physiological indicators over extended periods. However, due to the high sensitivities of soft sensors to multiple stimuli, decoupling the effects of various physical stimuli associated with accurately pinpointing the contributions of individual physiological markers remains a huge challenge. This article aims to provide a comprehensive review of recent advances in multifunctional, skin-like wearable sensors, with a particular emphasis on the mechanisms of signal transduction, microengineering designs, and their diverse applications in both health monitoring and human-machine interactions. It elaborates on the operational principles of various wearable sensors, such as triboelectric, resistive, piezoelectric, and capacitive sensors, each uniquely adept at detecting a range of stimuli. This article also examines recent advances in conceptualizations and methodologies for isolating specific stimuli from the mix of multiple physiological signals. Furthermore, this review highlights potential applications of these multimodal skin-like wearable sensors. Finally, opportunities and challenges facing multimodal wearable sensors are also discussed, exploring their potential in wearable intelligent systems tailored for diverse applications.