3D printed elastic fluoropolymer with high stretchability and enhanced chemical resistance for microfluidic applications

Elastomeric materials, most prominently polydimethylsiloxane, are of great importance for microfluidic systems. Unfortunately, most elastomeric materials used in these systems so far show poor chemical resistance. Fluorinated elastomers are promising for chemistry-on-chip applications performed on these microfluidic systems, but challenging to shape on the microscale and difficult to bond which is a required step for the fabrication of embedded chips. In this work, a custom-synthesized fluorinated photocurable resin which can be structured using vat photopolymerization 3D printers, and shows a high elasticity combined with a remarkable chemical resistance was demonstrated. The material provides excellent stretchability, with a linear deformation capability of 523% and remains stretchable even after being soaked in tetrahydrofuran for 24 h. By using multi-material printing microfluidic chips with bonded hard and soft segments of different fluorinated resins were fabricated. Also, a variety of chemically resistant microfluidic components including pneumatic valves and peristaltic pumps were proven feasible. This novel fluorine-containing resin is expected to initiate further advancements of chemistry-on-chip application.