Accurate real-time microbial monitoring of water environment is of paramount importance to crew health as well as to ensure proper functioning and control of the life support system during space exploration. The existing methods are time-consuming and labor-intensive, and the devices used are bulky, consumable-hungry, and ill-suited for spacecraft deployment. We propose to develop and demonstrate a novel, fully automated, microfluidics-based sensor for detection and identification of microbes in water. The final product will be compact, accurate, fully integrated and automated, power-effective, and fieldable in research and space environments. The program objectives will be accomplished via several innovations: (a) a milli-fluidic microbe preconcentrator to improve detection sensitivity; (b) CFDRC's proprietary dielectrophoresis technology will be adapted to develop a dielectrophoretic focuser for differentiation and separation of target microbes from complex sample matrices; and (c) microfluidic impedance spectroscopy-based cytometry to enable label-free detection and near reagent-free operation. In Phase I, we will demonstrate all critical components to establish proof-of-concept of the proposed technology. Phase II efforts will focus along two lines. First, component design optimization will be carried out with fabrication enhancements and extended testing and characterization for technology validation. Second, an integrated microfluidic cartridge and instrumentation capable of automated operation (sample processing and detection) will be developed. The prototype instrument will be demonstrated in both terrestrial and hypogravity environments (in collaboration with NASA researchers/facilities).