ECIS-UNM: Biomimetic Membranes for Water Purification

Clean water scarcity leads to disease, death, and often international tension. Limited clean water supplies face further stress due to its required use in a number of industrial processes. Reverse osmosis (RO) is currently the best method of desalination (making fresh water from seawater), but the energy requirements and costs for this process are tremendous and offset the benefits.

A nanoporous biomimetic membrane on a nanostructured support used for water desalination testing.

Inspired by how the human body filters water, Sandia, in conjunction with the University of New Mexico, has developed a synthetic biomimetic membrane capable of water desalination that requires significantly less energy than any other RO technology. Project lead Susan Rempe (Sandia) stated, “… our initial membranes achieved a 10-fold improvement in water purification efficiency compared with state-of-the-art RO membranes.”

By applying a combination of experimental and multiscale modeling techniques to natural biological channels, the team investigated the science of the interface between water samples, ions, and pores and determined the molecular structure-function relationships pertinent to desalination. They created new, selective membranes that optimized ion exclusion while maximizing water flow.

The membrane’s improved water flux is predicted to reduce excess energy costs by 88%. This technology received an R&D 100 award in 2011. Potential further applications of the membrane technology include liquid and gas separations, carbon dioxide capture and removal, and lithium-ion battery technology.

Read more about this ECIS-UNM partnership.