Current membrane fabrication processes are not sustainable as they are energy-intensive and require hazardous solvents. Additive manufacturing, due to its low waste production and the absence of harmful chemicals, can provide a more sustainable membrane manufacturing process. Up to this point, there was no way to 3D-print a membrane that meets the microfiltration pore sizes (1-10 μm) required in today’s industry. In this work, we showcase for the first time that membrane with pore size < 10 μm can be 3D-printed via a dual wavelength 3D printer. Polyethylene Glycol Diacrylate (PEGDA) hydrophilic membranes with cylindrical pores were designed and printed.

A dual-wavelength micro-stereolithography 3D printer has been employed to print the membranes. Photopolymerizable resins containing PEGDA monomers, were polymerized into membranes via a mixed projection of UV and blue light, creating unpolymerized pores and polymerized matrix respectively.

Using a pixel size of 1.4 μm, we could produce hydrophilic membranes with cylindrical pores and a diameter < 10 μm. These membranes were compared with benchmarking commercial PTFE membranes (JCWP14225, Merck, Germany) with the same pore size range. The resulting membranes exhibited good oil-repellent properties, indicated by the higher oil contact angle values under water. The permeability and filtration results also provide valuable insights into the material used for membrane printing. All in all, a successful microfiltration membrane has been produced via a fast, user-friendly and sustainable method.

We have introduced the next-generation 3D printing method for printing microfiltration membranes with precise pore size, shape, configuration, and arrangement. With further improvements, this technology will provide a new era in membrane manufacturing.