Low-cost automated flat-sheet membrane casting: An open-source, advanced manufacturing approach

Novel membrane materials developed in research labs struggle to gain widespread industrial adoption due in part to insufficient reproducibility and unreliable performance data. Open-source hardware approaches, especially 3D printing, enable the democratization of automation within a laboratory setting, and in the context of membranes, can minimize the inherent variability associated with manual methods of membrane casting. In this study, the native hardware and firmware of an inexpensive, conventional 3D printer was extensively modified for the purpose of flat-sheet membrane casting. Replicate poly (ether-ether ketone) (PEEK) membranes were cast with a thickness coefficient of variation of ∼10 % using the modified device. Cast membranes were used to assess the importance of controlling shear rate by characterizing both intra- and inter-film variability. Statistical differences in pure water permeability were observed across tested shear rates, with distinct morphological changes occurring to the membrane substructure. Overall, the technology developed in this study is shown to be an extremely useful approach for improving the process of developing membranes at the bench-scale.