Materials Science via Electron Tomography:
It is one of key points in understanding the origin of material properties to determine microscale and nanoscale structures. For this purpose, transmission electron microscopy (TEM) is widely used, which enables to analyze internal structure of materials with high spatial resolution. 
However, structural information that we can obtain from ordinary TEM is confined to two-dimensional one that is projected to a particular direction, which is against that real material possesses three-dimensional structure. 
In order to truly understand structure-property relationship, we study structure of materials with the use of electron tomography, which allows us to determine three-dimensional structure with the spatial resolution of several nano meters.