3D printed filtration and separation devices with integrated membranes and no post-printing assembly

Additive manufacturing, or three-dimensional (3D) printing, is an accessible, quick, and user-friendly tool for fabricating reactors and chemical processing devices. Here we report a method for printing filtration and separation devices using fused-deposition modelling (FDM) which incorporate commercial porous membranes. By using exogenous membranes, membrane pore size and material can be arbitrarily specified allowing much greater versatility in device design. We show for the first time that fully operational monolithic devices can be created without need for post-printing assembly and demonstrate the efficacy of the approach by making and testing three distinct devices: dead-end filters, which can be made in a range of sizes and are shown to fully remove micron-sized particles from a heterogenous mixture; liquid–liquid separators, which are shown to completely separate segmented flows of immiscible liquids; and a cross-flow filtration device, which is shown to achieve near full dye removal from an aqueous stream with a residence time of 3.4 minutes. For the cross-flow filtration device we describe a new “double-sided” printing technique whereby the plastic is directly printed onto both sides of the membrane to ensure the membrane is fully bonded to the 3D printed body. The range of devices showcased here highlights the versatility of the approach and its potential for use in chemical processing applications that require porous membranes.