Hot embossing of polymeric micro-mixer

• Main Author: Ik, Alex Jan Siong
• Other Authors: Tor Shu Beng
• Format: Final Year Project
• Language: English
• Published: 2010
• Subjects: DRNTU::Engineering::Manufacturing::Polymers and plastics; DRNTU::Engineering::Manufacturing::Product engineering; DRNTU::Engineering::Materials::Material testing and characterization
• Online Access: http://hdl.handle.net/10356/40129
• Institution: Nanyang Technological University

Low cost alternatives with efficient fabrication of microfluidic devices are crucial for supporting the demand for micro technologies in mass production applications. Past research had proven the effectiveness of hot embossing micro-features on substrate polymers. However, the replication quality varies with different molding and substrate materials. With increasingly popularity in hot embossing applications, the next level would be developing an efficient and systematic way of optimizing the process parameters with the goal of obtaining consistently good replication quality. This project aims to use Statistical ANOVA to evaluate and optimize hot embossing parameters for the fabrication of polymeric micro-mixers. PMMA and COC substrates were embossed with steel micro-machined mold for the replication quality inspection by Scanning Electron Microscope (SEM) and Confocal Imaging Profiler. Thermal characteristics of polymer were first evaluated by material characterization tests. Together with established effective parameters and past optimized values, the results were then used to design the experiment in Pre-DOE stages. DOE was then carried out to screen significant parameters for optimization. The responses collected were micron level measurements of various features. Approximate area calculations were included for quantitatively evaluating irregular channel profiles. For evaluating multiple responses, desirability functions were used to obtain a single response for evaluation. Next, optimization was carried out using response surface methods. Lastly, the optimized parameter values were subjected to repeatability testing. Results obtained show that both PMMA and COC substrates, replicated using the optimized parameter values, had better replication accuracy as well as lower dimensional shrinkage. COC substrates embossed were observed to have more welldefined features and better repeatability.