The field of microfluidics has enabled the development of powerful tools for analyzing and manipulating phenomena at the micro- and nano-scales, ranging from chemical analysis of biological samples to controlled synthesis of colloidal materials. In this dissertation we explore four unique platforms for real-time microfluidic measurement, analysis, and control systems with applications at the intersection of biomedicine and materials engineering. First, we show that a real-time biosensor can be used to perform closed-loop control of drug concentrations in the bloodstream of live animals. Second, we show that a commercially available cell-sorting instrument can be used to sort heterogeneous suspensions of synthetic microparticles based on shape using optical scattering measurements, resulting in monodisperse microparticle suspensions with well-defined morphology. Third, we report preliminary results for an image-based cell and microparticle sorter capable of sorting objects using two-dimensional high-speed microscopy and real-time image analysis. Finally, we report a contamination-resistant microfluidic assay for quantitative genetic detection based on real-time loop-mediated isothermal amplification, improving the robustness of point-of-care pathogen detection techniques.