News | May 24, 2019

Research shows 3D-printed chevrons enhance reverse osmosis water filters

US Army applies for a patent, technology transfer makes it available to industry

Water gushes from reverse osmosis water purification unit during disaster relief operations in the Phillipines.

Christopher Ruano/Air Force

An Army engineer has discovered that adding a V-shaped chevron to the filter membrane can significantly enhance the performance of reverse osmosis water purification units.

Jeremy Walker, a project engineer at the Army’s CCDC Ground Vehicle Systems Center in Michigan, found that the tiny chevrons can be 3D printed onto the surface of the semi-permeable membranes which are at the core of reverse osmosis water purification.

The channels formed by the chevrons eliminate the need to insert a mesh-type feed spacer between the membrane layers as has been done for many years.

Removing the spacer increases the membrane surface area available for water filtering, meaning increased throughput, but Walker also discovered that the raised chevron shapes helped rid the membranes of microscopic sediment and bacteria that can lower performance over time.

“The same feature configuration is also optimized for enhancing/increasing turbulence and scouring of the membrane when the flow through the filter is reversed during a cleaning operation, according to the Army’s U.S. patent application that published on Thursday.

“The predetermined configuration can also be optimized to capture bubbles in reverse flow and to oscillate such captured bubbles without harmful cavitation using acoustic streaming to further scour the membrane and the features themselves (e.g., in their cavities, etc.). The bubbles can then be flushed out in forward flow (also without cavitation).”

Thus, the tiny chevrons “eliminate the need for cleaning chemicals by allowing the use of a reverse flow of water (or other non-caustic cleaning solution) to keep the membrane surfaces clean and operating efficiently.”

News Article Image of Research shows 3D-printed chevrons enhance reverse osmosis water filters

Reservist Liana Valcin connects piping to a reverse osmosis water filtration unit during a water treatment training course at the Naval Construction Battalion Center in Gulfport, Mississippi, on May 7, 2019.

Jessica Dupree/Navy

Since the rise of reverse osmosis water filters as a practical technology in the late 1950s, the range of their application has expanded beyond the desalination of seawater.

In addition to military and industrial needs (including biotech and pharmaceuticals), government regulation and expanding populations has meant growing international demand for water purification technology, making reverse osmosis an economically attractive solution (relative to distillation).

In cooperation with the Army’s technology transfer program, TechLink is marketing Walker’s invention to qualified U.S. businesses that can make, use, or sell the invention commercially. As the Department of Defense’s national partnership intermediary, TechLink’s staff facilitate patent license agreements with such companies in part so that the military and the public can benefit from DOD inventions.

Dr. Brian Metzger, a senior technology manager at TechLink, has studied the patent application, the technology’s potential for commercialization in the marketplace, and is initiating the first phase of patent review and marketing. He said that interested companies are welcome to start a conversation so he can explain technical evaluation, the technology transfer process, and how TechLink provides no-cost licensing assistance.

“Reverse osmosis membranes are due for an upgrade and this is a great piece of intellectual property for companies that want to make it happen,” Metzger said. “Licensing from the DOD can be tricky for newcomers, but we’re here to help make sure companies of all sizes have access to the department’s invention portfolio.”


Company inquiries can be sent to Dr. Brian Metzger at brian.metzger@montana.edu or 406-994-7782.