Roll manufacturing of flexible microfluidic devices in thin PMMA and COC foils by embossing and lamination

Abstract

Microfluidics on foil is gaining momentum due to a number of advantages of employing thin films combined with the capability of cost-effective high-volume manufacturing of devices. In this work, ultra-thin, flexible Y-microreactors with microchannels of 100 lm width and 30 lm depth were fabricated in thermoplastic polymer foils. The fluidic pattern was hot roll embossed in 125 lm thick poly-methyl-methacrylate (PMMA) and 130 lm thick cyclic-olefin-copolymer (COC) films using a dryetched microstructured silicon wafer as a flat embossing tool in a laminator. The sealing of the channels was performed with two different techniques, one based on lamination of SU8 dry film resist (DFR) and the other one based on spin-coated poly-dimethylsiloxane (PDMS). Testing of the interconnected microreactor was carried out using two dye colorant solutions to demonstrate mixing.

Embossing Process

“…R2R hot embossing is the true destination of continuous and high-throughput fabrication for patterned polymeric films (Jiang et al, 2014b;Metwally et al, 2012;Vig et al, 2011). Process parameters, for example, roller temperature, applied pressure, and feed speed, have great influence on the formability of replicated features (Ishizawa et al, 2008;Mäkelä, Haatainen, & Ahopelto, 2011).…”

Taguchi method modelling of Nd:YAG laser ablation of microchannels on cyclic olefin polymer film

“…With increasing applications, the need to develop new processing techniques for the manufacture of devices utilising COP and COC becomes critically important. Techniques such as injection moulding [7], embossing [8], xurography [9], 3D-printing [10] and micromilling [11] have all been successful in the creation of micro-and nanoscale features on COC and COP substrates. Laser processing offers the ability for rapid, single-step prototyping of devices.…”

Rapid fabrication of nickel molds for prototyping embossed plastic microfluidic devices

“…As a result, significant effort has gone into the development of alternative plastic microfluidics prototyping methods. 8 Milled steel, aluminum, and brass, 2,4,9 cast PDMS, 10,11 epoxy, 12,13 and photoresist 14,15 have all been used as hot embossing molds for low throughput and prototyping applications. However, many of these methods still suffer from relatively long fabrication times and cannot withstand more than several dozen embossing cycles.…”