Bacterial Magnetic Particles for Applications in NDT&E, Detection of Flaws and Cracks in Sample Materials

Current NDT techniques are capable of identifying sub millimetre defects in structural materials. Nanoscale NDT however, necessitates development of new techniques for identifying and sizing surface and more importantly subsurface imperfections. The reliability of micro and especially nano scale components heavily depends on such new developments. This paper presents an attempt to explore the potential of magnetotactic bacteria for applications in NDT&E. Such bacteria having dimensions of a few microns can form single crystals of iron magnetite encapsulated in a magnetosome membrane. Crystals are structured in a long chain arrangement and polarised in the north / south direction, thus allowing the bacterial organisms to behave as magnets. Since their discovery in the 70s, different magnetotactic bacteria morphologies have been observed and a few have been successfully cultured. Work in progress at The University of Bolton has investigated using Magnetotactic Bacteria to detect flaws in materials. It was discovered that the bacteria can be used to show the presence of cracks and flaws in materials