A universal goal of technological development is the enrichment of human life. The fast developments of nano/micro technologies enable us to directly handle a single cell or a single molecule. This capability propels the molecular based diagnostic and therapeutic technologies to a new horizon. In this book, we not only examine the-state- of-art biotechnologies, but also present many cutting-edge research topics which will lead toward the next generation technologies for improving human health. With the capabilities of moving, stopping, mixing and concentrating minute amount of fluid and/or particles, microfluidic circuitry provides unprecedented functions for advancing sample preparation and cell culture processes. Integrated bio-marker sensors with microfluidics, it becomes possible to detect diseases in extremely sensitive and specific manner. With the cutting edge optical techniques and proper surface molecular modification, we can study and manipulate biological processes in live cell. While we have made significant progresses in studying and controlling the phenomena in the nano/micro scale, human health is a system issue with a length in the order of a meter. A disparity of several orders of magnitude in the length scales presents significant challenges. Our current and future tasks are to develop the seamless integration processes from materials through devices and eventually into engineering systems. Our ultimate goal is that these nano/micro technology based systems can effectively interface and direct the biological complex system toward desired fate.