Rapid Tooling for Microinjection Moulding of Proof-of-Concept Microfluidic Device: Resin Insert Capability and Preliminary Validation

Producing sustainable microfluidic devices on a large scale has become a trend in the biomedical field. However, the transition from laboratory prototyping to large-scale industrial production poses several challenges due to the gap between academia and industry. In this context, prototyping with a mass production approach could be the novel strategy necessary to bridge academic research to the market. Here, the performance of polymer inserts to produce PMMA microfluidic devices using the microinjection moulding process is presented. Inserts were fabricated with an additive manufacturing process: material jetting technology. The importance of the inserts’ orientation on the printing plate in order to produce samples with more uniform thickness and lower roughness has been demonstrated using a flat cavity insert. In addition, preliminary tests were carried out on microstructured inserts with inverted channels of various cross-section shapes (semi-circular or trapezoidal) and widths (200 or 300 µm) in order to investigate the microstructures’ resistance during the moulding cycles. The best geometry was found in the channel with the trapezoidal cross-section with a width equal to 300 µm. Finally, a preliminary microfluidic test was performed to demonstrate the devices’ workability.