Atoms are the basic building blocks for all ordinary matter in the universe. The ultimate goal of nanotechnology is to change the functionalities of devices by modulating individual atoms since the arrangement of them strongly affectthe physical properties of materials. While it needs the characterization and identification of each site of the whole system in three dimension (3D).

Crystallography was invented and used to get the 3D structure of crystals by X-ray diffraction, which makes it famous since last century. But it assumes the perfect crystal and it uses average effect to detect the averaged structure of massive same materials by characterize them together. While real materials can never be perfect, there are a lot of imperfections in the worlds, such as the point defects, line defects (dislocations), chemical order/disorder and interface like grain boundaries, stacking faults or material surface morphology. Actually, these are the most important structure that decided the materials properties. Moreover, the fine structure feature of amorphous materials in 3D can never be acquired by crystallography since most of them are isotropic, so it can only provide a one dimensional information. The recent development of electron microscopy based imaging techniques such as Atomic electron tomography and Electron ptychography enable us to see the individual atoms in two and three dimension without the assumption of crystallinity.

Our lab is at the frontiers of electron imaging methods to not only correlate the 3D atomic structure and properties of different materials, but also monitorng the dynamic process in atomic resoltion with different conditions such as heating and electro-chemistry among time.