Researchers at the University of Bath suggest developments in 3D printing techniques could enable membrane capabilities to be significantly advanced.
The work is part of the University’s Centre for Advanced Separations Engineering (CASE). It represents the first time researchers have assessed the impact 3D printing techniques could have on membrane fabrication.
Membranes are a semi-permeable selective barrier that isolate molecules in a mixture within a gas or liquid into two streams. A key example of this is the separation of salt from water for desalination using reverse osmosis membranes.
With prior applications in a variety of industries from medicine to art, and engineering to sportswear, its use in separation membrane engineering is relatively new. It has been suggested that 3D printing has the ability to create almost any geometrically complex shape or feature in a range of materials across different scales. Membranes are currently restricted mainly to tubular/ hollow fibre and flat surface configurations due to the limitations of current manufacturing processes. As a result, the precision of present membranes are limited in successfully separating certain properties.
The use of 3D printing offers novel membrane preparation techniques that can produce membranes of different shapes, types and designs. These can be more precisely designed, fabricated and controlled than any other membrane fabrication method currently available. Bath University’s study, which evaluates existing knowledge of the pros and cons of different 3D printing techniques, as well as the potential developments of membrane fabrication, identifies a bright future in which 3D printing will allow innovative and more accurate membranes.
Any increased capabilities may have significant implications for a number of key industries, including the water industry. These new membranes, with designer pores and surface shapes, will enhance micro-mixing and shear flow across the membrane surface. They will be able to reduce the energy and down-time associated with cleaning blockages and fouling of the membranes.
“This review is the first to explore the possibility and challenges of using 3D printing for producing separation membranes,” said Dr Darrell Patterson, Director of the Centre for Advanced Separations Engineering at the University of Bath. “Although 3D printing technology is not quite well enough developed to yet produce large scale membranes that will be cost competitive with existing products, this work does signal what the future possibilities are with 3D printing, to produce membranes beyond that which are currently available. (This includes) controlled complex pore structures, integrated surface patterns and membranes based on nature.”
The paper, titled ‘Perspective on 3D printing of separation membranes and comparison to related unconventional fabrication techniques, was published in the Journal of Membrane Science. It can also be viewed on the Science Direct website.