Antimicrobial Copper - Functional Surfaces and Factors of Toxicity

• Applicant: Professor Dr.-Ing. Frank Mücklich
• Subject Area: Synthesis and Properties of Functional Materials
• Term: from 2013 to 2015
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 247643033

By precisely tuning the surface parameters topography and chemistry using laser interference surface structuring, model surfaces on the scale of bacteria have been generated during the first proposal. Using these, the surface parameters that govern wetting, ion release and bacterial adhesion on metallic surfaces have been evaluated. In addition, the oxidation behavior of copper during viability tests with bacteria as well as the combination of copper and silver by laser cladding have been implemented and investigated on. The tuned material and surface parameters have been precisely correlated to the antimicrobial efficiency of these surfaces.The here described follow-up proposal is motivated by the partially surprising results from the first proposal. The emphasis here lies on the role of the immediate contact between material and bacteria as well as the electrochemical influence of differentiating surface potentials on the contact killing. As it has been quantitatively shown during the first proposal, that the contact between bacteria and metallic surface significantly governs the killing rate, topographically tailored copper surfaces will be created in the follow-up proposal. On these, it will be subject of investigation if and how the killing rate can be influenced by variation of the effective contact area. In the second part of the project, chemical surface pattern with controlled potential differences will be induced by laser interference lithography and consecutive metal coating. By using these patterned surfaces, the influence of potential differences will be studied by variation of material combination and pattern scale. In order to correlate it with antimicrobial efficiency, the bacterial adhesion on the investigated surfaces will be quantitatively characterized by microscope, parallel to these studies. This research is specifically relevant for the society in the light of rising antibiotics resistance of dangerous germs and the fight of partly deadly and highly infectious diseases by employing antimicrobial materials.

• DFG Programme: Research Grants
• International Connection: Switzerland
• Participating Person: Professor Dr. Marc Solioz