Ambient hot embossing of polycarbonate, poly-methyl methacrylate and cyclic olefin copolymer for microfluidic applications

Microfluidic devices offer an attractive route towards the miniaturization of chemical and biological processes in lab-on-chip applications. Lab-on-chips can be fabricated from inexpensive polymers such as polycarbonate (PC), poly-methyl methacrylate (PMMA) and cyclic olefin co-polymers (COC). Hot embossing of polymers is an attractive route to fabricating chips with feature dimensions ranging from a few microns to centimeters. Here, using ambient hot embossing, we present the optimization of key hot embossing parameters (temperature and pressure) for the realization of high mold-to-substrate feature fidelity in PMMA, PC and COC substrates. Taguchi analysis of experiment results indicate that PMMA and PC substrates, as compared to COC substrates, are more responsive to temperature increases above their respective glass transition temperatures. This difference in polymer viscoelastic behavior is proposed to occur due to the variation of the polymers' dynamic viscosity.