Simultaneous improvement of surface finish and bonding of centrifugal microfluidic devices in cyclo-olefin polymers

Two key issues in the manufacturing of microfluidic devices are to obtain low surface roughness, i.e. in the range of nanometers (to facilitate optical detection and controlled flow through microfluidic networks), and to achieve robust bonding. Here we report that a chemical polishing step, used for smoothening the surface of cyclo-olefin polymer (COP) components manufactured by micromilling, reduces the surface roughness (to Ra ∼ 150 nm) and facilitates a leak-tight COP-COP bond. We report new results on COP structuring and surface characterization by white light interferometry (WLI), infrared spectroscopy (FTIR-ATR), contact angle measurements and transmittance measurements, as well as demonstrations of a functional thermally bonded centrifugal microfluidic devices