Polymer membrane patterns get 3D makeover

Commonly used in many process environments for water purification, food processing, and in energy applications such as fuel cells, these polymer ‘ion exchange’ membranes are structured in the form of thin sheets.

However, the use of 3D patterns on top of the membrane surface is now being explored to solve issues such as fouling often associated with membrane applications.

We thought if we could use 3D printing to fabricate our custom-synthesized ion exchange membranes, we could make any sort of pattern and we could make it quickly

Michael Hickner, associate professor of materials science and engineering at Penn State

The manual creation of these patterns can be very time intensive, and limited in scope. To solve this issue, researchers from Penn State developed a custom 3D photolithographic printing process.

A paper published in the American Chemical Society's journal ACS Applied Materials and Interfaces describes the process, which the researchers hope will speed development of new membrane patterns.

"We thought if we could use 3D printing to fabricate our custom-synthesized 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 at Penn State.

The paper's lead author, Jiho Seo, said: "While surface-patterned membranes have been studied previously, this is the first 3D-printed example of these structures and the first model that really explains the resistance decrease in a quantitative way.

“This insight gives us a design tool to continue to innovate and create new patterns for further improvements along with changing the intrinsic chemistry of the material."

The team plans to continue to develop the geometry and chemistry of membranes being printed, while also learning to print completely new materials.