What Our Nose Does Naturally: Liquid-Coated Air Filters Capture More Pollutants
The mucus that coats nasal hairs plays a central role in cleaning the air we breathe. It filters out pollen and dust particles that could otherwise reach deep into the lungs. An international team of researchers, including scientists from the Max Planck Institute for Polymer Research in Mainz, has demonstrated that this natural principle can also be applied to technical air filters, such as those used in air conditioning systems. By coating the filters with a thin liquid layer, even the tiniest particles can be captured and bound more effectively than with conventional dry filter systems — without obstructing the airflow.
Inspired by the mucus-covered nasal hairs in the human body, the researchers developed a filter that uses a microscopically thin liquid coating to trap particles through capillary forces. Liquid bridges form between the dust particles and the fibers of the filter, preventing the particles from detaching and leading to compact dust aggregates. Unlike conventional filters, which gradually become clogged and restrict airflow, the new filter remains permeable for longer — while still providing excellent filtration performance.
“This technology is a step toward long-lasting, energy-efficient filtration systems,” explains Dr. Michael Kappl of the Max Planck Institute in Mainz, one of the contributing authors. “What’s particularly impressive is that even ultra-fine particles in the nanometer range are reliably captured.”
The project brings together expertise from South Korea (Chung-Ang University, Incheon National University), the USA (University of Cincinnati), and Germany (Max Planck Institute for Polymer Research). Leading the effort was the team of Professor Sanghyuk Wooh (Chung-Ang University, Seoul), which developed the core idea and design.
Professor Hans-Jürgen Butt, Director at MPI‑P, emphasizes the importance of international collaboration: “Air purification is a global issue — and this work shows how interdisciplinary research across continents can lead to tangible solutions.”
This new filter technology is suitable for a wide range of applications, including ventilation and air conditioning systems, industrial exhaust systems, medical protective masks, clean rooms, such as dust and smoke filters in urban environments. Due to its high particle-capturing efficiency combined with low energy consumption, the technology has the potential to reduce long-term costs and lower environmental impact.
The results have now been published in the renowned scientific journal Nature.