Micro fabrication of cyclic olefin copolymer (COC) based microfluidic devices

Microfabrication of polymer using hot embossing technique are becoming increasingly important and considered as low-cost alternative to the silicon or glass-based micro-electro-mechanical systems technologies. This report is based on a parametric study on the hot embossing of cyclic olefin copolymer (COC) (Topas-6015 grade). The key process parameters in hot embossing such as the embossing temperature, load, the holding time and the demolding temperature significantly impact the quality of the embossed product. The work was performed to understand the influence of the various process parameters on the embossed micro-size patterns with the aim to develop the capability for microfluidic devices manufacturing. Microembossed polymer replicates were measured using a PLμ confocal microscope and inspected using a scanning electron microscope. It was established that the optimal embossing temperature for COC is 10°C above its T_g, while an optimal embossing load of 2.94 kN and holding time of 180 s are required. We have also demonstrated the effective sealing of the microchannel without destroying the channel integrity by thermal bonding technique.