Development of highly efficient coalescence separators based on new three-dimensional and nanostructured filter media

The separation of liquid particles from a gaseous medium is a necessary step in many industrial processes. Such separation processes are required during exhaustion of oil vapours of machine tools. Aerosoles with dimensions lower than one micrometer develop at cutting surfaces due to high speeds and temperatures from cooling lubricants. These particles with diameters of about 100 – 500 nm are hazardous to human health.

This project, supported by the Federal Ministy of Education and Research within the framework of BIONA, aims at improving the separation of these small particles by applying a biomimetic approach. The goal is to develop new filter media by combining hydrophobic and hydrophilic surfaces. Several organisms appear to use such surfaces in order to achieve a high degree of droplet separation: 1) desert plants (Stipagrostis sp.), 2) desert beetles (Stenocara sp). Additionally, the self-cleaning ability of many organismic surfaces (particularly that of lotus plants) by nanostructures will be applied. The combination of these various biomimetic mechanisms into technical devices is expected to achieve a highly efficient droplet separation with rapid conduction of the collected liquids.

Industrial partners:

Hofmann Maschenstoffe GmbH
Karl Jetter & J. Herter GmbH & Co. KG
Keller Lufttechnik GmbH
Junker Filter GmbH

Cooperation partners:

Institute of Textile Technology and Process Engineering Denkendorf, Dr. Thomas Stegmaier


July 2011 Award: TECHTEXTIL innovation prize 2011


Nørgaard, T. Ebner, M., Dacke, M. (2012): Animal or Plant: Which Is the Better Fog Water Collector? PLOS ONE 7(4): e34603. doi: 10.1371/journal.pone.0034603

Roth-Nebelsick, A., Ebner, M., Miranda, T., Gottschalk, V., Voigt, D., Gorb, S., Stegmaier, T., Sarsour, J., Linke, M. & Konrad, W. (2012): Leaf surface structures enable the endemic Namib desert grass Stipagrostis sabulicola to irrigate itself with fog water. Journal of The Royal Society Interface, 9, 1965-1974. DOI: 10.1098/rsif.2011.0847

Ebner, M., Miranda, T. & Roth-Nebelsick, A. (2011): Efficient fog harvesting by Stipagrostis sabulicola (Namib Desert bushman grass). Journal of Arid Environments, 75, 524-531. DOI: 10.1016/j.jaridenv.2011.01.004