Fabrication of μFFE Devices in COC via Hot Embossing with a 3D-Printed Master Mold

The fabrication of high-performance microscale devices in substrates with optimal material properties while keeping costs low and maintaining the flexibility to rapidly prototype new designs remains an ongoing challenge in the microfluidics field. To this end, we have fabricated a micro free-flow electrophoresis (mu FFE) device in cyclic olefin copolymer (COC) via hot embossing using a PolyJet 3D-printed master mold. A room-temperature cyclohexane vapor bath was used to clarify the device and facilitate solvent-assisted thermal bonding to fully enclose the channels. Device profiling showed 55 mu m deep channels with no detectable feature degradation due to solvent exposure. Baseline separation of fluorescein, rhodamine 110, and rhodamine 123, was achieved at 150 V. Limits of detection for these fluorophores were 2 nM, 1 nM, and 10 nM, respectively, and were comparable to previously reported values for glass and 3D-printed devices. Using PolyJet 3D printing in conjunction with hot embossing, the full design cycle, from initial design to production of fully functional COC mu FFE devices, could be completed in as little as 6 days without the need for specialized clean room facilities. Replicate COC mu FFE devices could be produced from an existing embossing mold in as little as two hours.

Automated summary

The challenge of fabricating high-performance microscale devices in the microfluidics field is addressed in this study. A micro free-flow electrophoresis (mu FFE) device is fabricated using PolyJet 3D printing and hot embossing techniques, with channels fully enclosed through solvent-assisted thermal bonding. The device achieves baseline separation of fluorescent compounds and offers a short production cycle and low cost.