3D fabrication technique promises rapid build and test of new polymer membranes

Ion exchange membranes have applications in fuel cells, as well as in water purification, desalination, removal of heavy metals and food processing.

Most of these membranes are thin, flat sheets but recent work has shown that by creating 3D patterns on top of the 2D membrane surface, certain hydrodynamic properties emerge that improve ion transport or mitigate fouling.

Making these so-called profiled patterned membranes involves etching a silicon mould with the desired pattern, pouring in the polymer and waiting for it to harden, a process that is time-consuming, expensive, and results in a single pattern type.

"We thought if we could use 3D printing to fabricate our custom-synthesised ion exchange membranes, we could make any sort of pattern and we could make it quickly," said Michael Hickner, associate professor of materials science and engineering, Penn State.

In a paper published in ACS Applied Materials and Interfaces, Hickner's team describes the development of a custom 3D photolithographic printing process similar to stereolithography.