3D visualization and characterization of nano structured materials

This paper reports a study on 3D topography and tomography visualization of materials with micro and nano features. SEM stereo imaging technique is employed to characterize surfaces by reconstruction. With this technique, diatomaceous frustules and sputtering yield of metals were analyzed. X-ray nanotomography (nCT) is used for characterization of a polymer electrolyte fuel cell (PEFC) gas diffusion layer (GDL) with 680 nm resolution. Focused ion beam/SEM (FIB/SEM) nanotomography is developed to visualize materials with resolution from 8 to 60 nm. The technique was used to reconstruct glass micropipette tips and PEFC microporous layers (MPL). In addition, porosity of PEFC layers and roundness of micropipette tips can be extracted from the reconstructed models. As an example of the applications of the FIB/SEM technique, tomographic images of PEFC MPL is combined with the lattice Boltzmann (LB) numerical modeling to anticipate the permeability which helps understand the flow inside the porous layers of the fuel cell and provide the opportunity to improve the performance.