Roll-to-Roll Thermal Nanoimprinted Microfluidic Separation Devices

Here we propose and demonstrate Roll-to-Roll (RtR) thermal nanoimprint lithography for high volume production of microfluidic devices. In this study we have used an earlier proposed microfluidic separation technique called pinched flow fractionation (PFF) as the microfluidic model system. Formation and sealing of the microfluidic channels were carried out in a two step fabrication process with a RtR thermal nanoimprint machine. The process was optimized to enable fabrication of micrometer sized channels and we established a production line with a volume of 240 devices/hr; approximately 60 times larger compared to planar thermal nanoimprint lithography. Furthermore, the device materials and machine cost in RtR fabricated PFF devices is 0.50 /devices, approximately 200 times cheaper compared to planar thermal nanoimprint lithography. The RtR nanoimprinted devices were used for separation of 1 ?m and 3 ?m polystyrene microspheres, and the separation results were compared against devices having the same layout but fabricated by planar thermal nanoimprint lithography. Finally, separation of the microspheres has been enhanced with a dummy structure in the broadening segment. This dummy structure also gives better imprint results.