Microfluidic Molecular Diagnostic Chips: Functional Modules, Integration Strategies, and Emerging Applications

Microfluidic molecular diagnostic chips are redefining point-of-care testing by integrating the entire analytical workflow spanning from sample preparation to result detection into a single, compact platform. This comprehensive review systematically examines five essential functional modules-mixing, fluid actuation, reagent storage, separation, and reaction chambers-that underpin integrated lab-on-a-chip systems. For each module, the underlying physical principles and representative technologies are critically analyzed with respect to performance metrics (e.g., efficiency and throughput) and structural complexity. By elucidating how microscale transport phenomena, including laminar flow control, efficient heat and mass transfer, and precise reagent manipulation, enable the automation of biological assays, this review clarifies the diagnostic capabilities achievable on a chip, including nucleic acid amplification, immunoassays, and label-free molecular sensing. Emerging trends in modular design, scalable fabrication methods, and intelligent autonomous operation are discussed as critical drivers for next-generation sample-to-answer systems. Overall, this review provides a comprehensive, application-oriented framework to guide the development of portable, intelligent, and clinically deployable molecular diagnostic platforms.