Microfluidic technologies for wearable and implantable biomedical devices.

Microfluidic technologies are transforming wearable and implantable biomedical devices by enabling precise, real-time analysis and control of biofluids at the microscale. Integrating soft, biocompatible materials with advanced sensing and fabrication techniques, these systems offer promising solutions for continuous health monitoring, targeted drug delivery, and responsive therapeutics. This review outlines critical design considerations, material strategies, and fluid handling mechanisms essential for device performance and biocompatibility. We systematically examine key fabrication approaches-including soft lithography, 3D printing, laser micromachining, and textile-based methods-highlighting their advantages and limitations for wearable and implantable applications. Representative use cases such as sweat analysis, interstitial fluid sampling, ocular diagnostics, wound monitoring, and therapeutic systems are explored, alongside current challenges in long-term stability, power management, and clinical translation. Finally, we discuss future directions involving bioresorbable materials, AI-assisted diagnostics, and wireless integration that may drive the next generation of personalized microfluidic healthcare systems.