Smart flexible wearables for non-invasive body fluid monitoring: a multidisciplinary roadmap and future directions

• Review of smart wearable technologies for health monitoring. • Evaluation of advanced materials in wearable devices. • Non-invasive biomarker detection through body fluids. • Real-time physiological monitoring for disease prevention. • Energy-harvesting techniques for self-powered devices. • Challenges in sensor miniaturization and comfort. Real-time monitoring and understanding of individual health status not only enable the prompt identification of potential health concerns, thereby facilitating timely interventions to prevent severe injury or mortality, but also assist individuals in managing their lifestyles effectively, improving health behaviors, and enhancing overall quality of life. The paradigm shift toward non-invasive health monitoring through smart flexible wearables represents a transformative convergence of multidisciplinary innovation. Advancements in textile science, materials science, biomedicine, computer science, and electronic information and communication technology have resulted in the continuous emergence of flexible, comfortable, sensitive, and precise smart wearable monitoring devices. The range of monitoring indicators has expanded beyond traditional metrics, such as body temperature, blood pressure, and heart rate, to encompass a range of biomarkers and biomolecules found in bodily fluids. Furthermore, the targets for monitoring have broadened from blood to encompass sweat, interstitial fluid, saliva, tears, and exhaled breath, marking a transition from invasive to non-invasive methodologies. Therefore, to inspire the continuous enhancement and evolution of smart wearable products and foster the development of innovations, this review summarizes existing advancements, identifying critical challenges, and offering perspectives on future innovations, this study aims to serve as a multidisciplinary roadmap for the development of next-generation wearable technologies. This review aims to provide a multidisciplinary roadmap for the development of next-generation wearable technologies, highlighting key materials and application contexts associated with these technologies. Finally, this review outlines the challenges faced by this technology and presents perspectives on future advancements.