The field of microfluidics has been an emerging area of popular research in the fields of science and engineering since it first emerged in the early 1980s. Residing at the intersection of engineering, chemistry, physics, and biology, microfluidics problems have posed some of the greatest challenges of science in recent times. Due to the extreme difficulty in manipulating, measuring, and controlling the fluid volumes and velocities associated with microfluidics applications, many significant scientific advances have been held out of reach. Of the all the bottlenecks associated with microfluidics, the accurate measurement and characterization of fluids in these systems has proven to be one of the most challenging. Sensors in this category are constrained to geometrically minute spaces, typically on the sub-millimeter scale, making conventional measurement techniques obsolete for many applications. This book discusses the analysis and fabrication techniques associated with designing, building, and testing a microfluidic flow rate and temperature sensor.