A breakthrough in filtration technology from European researchers could transform how the world produces clean water and processes sensitive liquids. Scientists at the Fraunhofer Institute for Electron Beam and Plasma Technology FEP in Dresden, Germany, working with the startup CNM Technologies GmbH, have created carbon nanomembrane (CNM) composite filters just a few nanometres thick. In laboratory tests, these membranes achieved at least a fivefold improvement in salt rejection compared with standard reverse-osmosis membranes while maintaining comparable water flow rates.
The development emerged from the European Union’s Horizon Europe-funded Convert2Green project, which ran from 2023 to 2025. The initiative established an Open Innovation Test Bed to accelerate climate-neutral and circular materials across key European value chains. Fraunhofer FEP contributed its expertise in electron-beam and plasma coating processes, successfully scaling the laboratory concept into a continuous roll-to-roll manufacturing sequence suitable for industrial production.
How the Nanometre-Scale Barrier Works
Conventional reverse-osmosis systems rely on relatively thick, dense polyamide membranes that demand high hydraulic pressure and substantial electrical energy to force water molecules through. The new CNM layers are single-molecule-thick, two-dimensional carbon networks featuring sub-nanometre pores. Water molecules pass with minimal friction, while dissolved salt ions, organic compounds and micro-contaminants are retained almost completely.
This structural advantage allows the membranes to operate at lower pressures. Reduced pressure requirements translate directly into lighter pumping infrastructure, smaller plant footprints and significant cuts in energy consumption – critical advantages for large-scale desalination and industrial water treatment facilities facing rising energy costs and climate pressures.
Cross-linked carbon nanomembranes also offer superior resistance to biofouling and chemical degradation. Their ultra-smooth surfaces and robust cross-linking help extend operational life and reduce the frequency of aggressive cleaning cycles that plague traditional polymer membranes.
Applications Beyond Drinking Water
The technology’s potential reaches well beyond municipal water supplies. In food and beverage processing, manufacturers traditionally concentrate liquids by boiling, a process that can destroy delicate flavours and heat-sensitive proteins. Forward osmosis using CNM filters enables gentle water extraction at ambient temperatures, preserving quality while lowering storage and transport costs for concentrates.
Researchers further enhanced the membranes by integrating nanoscale metal layers, producing ultra-thin metal foils only tens of nanometres thick. These open pathways for next-generation sensors, optical devices and clean-energy components, expanding the economic value of the underlying coating technology.
Dr Matthias Fahland, project manager at Fraunhofer FEP, emphasised the dual achievement: “What is crucial here is not only the technological result itself, but also the fact that we have established structures within the project that will enable future innovations to be transferred more rapidly into market-ready applications.”
From Laboratory to Industrial Scale
A decisive milestone was the first complete integration of molecular-layer deposition and electron-beam cross-linking into a high-speed, continuous roll-to-roll process. This step addresses a common bottleneck in nanomaterials research – bridging the gap between laboratory prototypes and cost-effective manufacturing.
Although Convert2Green formally concluded, the Open Innovation Test Bed infrastructure continues to support small and medium-sized enterprises. Companies can access pilot production lines, testing facilities and digital platforms designed to accelerate the move from concept to market. The technology will be showcased at the pro flex 2027 conference in Dresden on 25–26 May 2027, providing a platform for further industrial partnerships.
Global Relevance for Water-Stressed Regions
Access to safe drinking water remains uneven across the world. In many coastal and arid regions, salinity intrusion and limited freshwater resources already strain communities and agriculture. Lower-energy, higher-efficiency membranes could ease the economics of desalination and wastewater reuse, supporting efforts such as those documented in South Asian groundwater and tap-water initiatives.
The membranes’ ability to produce ultrapure water at reduced pressure also holds promise for pharmaceutical manufacturing, electronics and other industries requiring high-purity process water. By cutting energy intensity, the technology aligns with broader climate and sustainability goals, including reduced greenhouse-gas emissions from water treatment infrastructure.
Challenges and Next Steps
While laboratory results are compelling, commercial deployment will require further validation under real-world conditions – variable feed-water quality, long-term fouling behaviour and full-scale module durability. Cost competitiveness against mature reverse-osmosis systems will also determine adoption rates. The Convert2Green network’s continued support for SMEs is intended to shorten this pathway by providing shared testing and scale-up resources.
The core innovation rests on proven electron-beam processing techniques already familiar in flexible electronics and packaging industries. This familiarity may ease integration into existing production lines and regulatory frameworks in different jurisdictions.
The ultra-thin CNM filtration system represents more than an incremental improvement in membrane performance. It demonstrates how targeted European research collaboration can deliver technologies with global reach – lower energy demand for clean water, gentler processing for food and beverages, and enabling materials for sensors and energy devices. As water stress intensifies in many parts of the world, such advances offer practical tools for more efficient and sustainable resource management.
The pro flex 2027 conference will provide the next public platform for industrial partners to explore commercial pathways. Until then, the Convert2Green Open Innovation Test Bed remains open to enterprises seeking to evaluate and adapt the technology for their specific needs.
(Courtesy owsa.in)