Exploration of the evolution of nanotechnology via mapping of patent applications

This study explored the evolution of nanotechnology based on a mapping of patent applications. Citations among patent applications designated to the European Patent Office were intensively analysed. Approximately 4300 nanotechnology patent applications linked through citations were mapped. Fifteen domains of nanotechnology patent applications were found in the map in 2003. The domains cover a wide range of application fields; they are domains related to measurement and manufacturing; electronics; optoelectronics; biotechnology; and nano materials. Maps in several reference years registered the evolution of nanotechnology, where the breadth of application fields has been broadening over time. Direct and indirect knowledge flows among different domains of nanotechnology are seemingly small at the present. Each domain of nanotechnology is likely pushing the technological frontier within its own domain. The exception is sensing and actuating technologies on the nanometre scale. Direct and indirect knowledge flows to/from this domain describe their vital role in nanotechnology. Countries' specialisation was also analysed. Patent applications from the United States and the European Union cover a wide range of nanotechnology. Inventive activities in Japan are, however, strongly focusing on electronics. Intensive knowledge creation in specific technologies was found in Switzerland and Korea.