Rapid prototyping of fluoropolymer microchannels by xurography for improved solvent resistance

Abstract

Microchannels made of fluoropolymers show potential merits due to their excellent solvent resistance, but such channels have not been widely used because of the complexity to fabricate them. This communication describes a method to prototype microfluidic devices using fluoropolymer films. The fabrication requires only two steps; cutting fluoropolymer films with a desktop cutting plotter and applying heat and pressure to laminate them. The method is rapid, simple, and low-cost. The conditions for heat press were identified for two common fluoropolymers: polytetrafluoroethylene and fluorinated ethylene propylene. The laminated films were confirmed to remain sealed with an internal pressure of at least 300 kPa. The fabricated devices were tested for the resistance to a set of organic solvents that would not be compatible with typical devices fabricated in polydimethylsiloxane. To highlight the potential of the fluoropolymer devices fabricated in this method, generation of droplets in a continuous stream of organic solvent using a T-junction channel was demonstrated. Our method offers a simple avenue to prototype microfluidic devices to conduct experiments involving organic solvents such as organic chemistry and in-channel synthesis of microparticles.