Characterizing emergence using a detailed micro-model of science: Investigating two hot topics in nanotechnology

The structure and evolution of science and technology can be studied at multiple levels. Most such studies explore the developments of fields, disciplines, or specialties. Given the large numbers of articles underlying these analyses, developments appear to be continuous and smooth in most cases. By contrast, analysis of structure and evolution at the level of research problems results in a combination of stable and instable features. We characterize the development of two emerging topics within nanotechnology - graphene and dye-sensitized solar cells (DSSC) - at the research problem level. The analysis shows two different types of emergence, one in which the topic is spread throughout a large number of research problems prior to emergence and does not become a research problem of its own for many years, and one in which the topic quickly dominates a few research problems.