Dragomir Davidovic's research focuses on the exploration of physical properties that emerge in objects when their size approaches nanometer-scale. The objects of study are metallic or insulating particles, molecules, atomic-scale diameter wires, and droplets of one phase surrounded by another phase. Recent advances in lithography enable attachment of these objects to larger scale conducting electrodes, making it possible to explore their physical properties by electronic transport. The properties of nanoscale objects can be fundamentally different from those in bulk. As an example, whereas in bulk metals, the energy spectrum of conduction electrons is continuous, in metallic nanoparticles the spectrum is discrete. As a result, metallic nanoparticles are more like atoms than bulk metals, and nanoparticles are commonly referred to as artificial atoms.