A key feature of my research is to develop a transmission electron microscope (TEM) into an atomic-scale nano-chemistry laboratory to fabricate, modify and characterize samples so that crucial structure property studies and synthesis studies can be conducted in high spatial resolution and high temporal resolution. In this presentation I will show a variety of electron beam driven reactions and electron beam engineering techniques in which we can fabricate and manipulate nano-materials. I will also show how one can structure and look at structure-property relationship of graphene devices, both fabricated and examined in-situ in a TEM.