Possibility of biological micromachining used for metal removal

Besides the physical and chemical machining methods, a biological machining method has been presented. The experimental results show that machining of pure iron, pure copper and constantan by a special bacterium, Thiobacillus ferrooxidans, was possible. A micro gear and grooves on pure copper piece were bio-machined. The depth of the groove so bio-machined was directly dependent on the machining time. The biomachining mechanism has been analyzed from the electron-transport chain (ETC) in the T. ferrooxidans membrane, and its developing direction has been also discussed.