Microfluidics for most bio-related diagnostic applications typically requires single usage disposable chips to avoid bio-fouling and cross-contamination. Individual piece-wise manufacturing of polymeric microfluidic devices has been widely employed in recent years. To significantly lower the manufacturing costs, one possible way is to improve the production yield of polymer microfluidic chips via the hot roller embossing method. This paper discusses the effects of varying the process parameters such as roller temperature, applied pressure and substrate preheating during hot roller embossing (according to a systematic set of experiment designs) and its influence on the corresponding mold to pattern fidelity in terms of normalized embossed depths on the poly (methylmethacrylate) (PMMA) substrate. Concurrently, pattern density studies on the mold were also conducted. Functional testing in terms of fluid flow and micromixing was carried out to evaluate the feasibility of using hot roller embossed PMMA substrates as microfluidic chips.