Autonomous Wearable Sensing Enabled by Capillary Microfluidics: A Review

Capillary microfluidic wearables are emerging as effective autonomous biosensing platforms for non-invasive monitoring of biofluids like sweat and saliva. This review discusses recent advancements in device designs that allow passive fluid sampling and integration with biochemical sensors, focusing on strategies like chrono-sampling and continuous flow. Key design elements such as burst valves and multilayer channels are highlighted for their role in reducing evaporation and biofouling. The review evaluates progress in electrochemical and optical biosensing for real-time measurement of analytes like cortisol and glucose, and addresses challenges in clinical validation and manufacturing scalability, providing a roadmap for future lab-on-skin diagnostics and personalized health monitoring.