1. Worldwide Nanotechnology Development: A Comparative Study of USPTO, EPO, and JPO Patents Xin Li Yiling Lin Hsinchun Chen Dec 2006

2. 2 Outline Introduction Background and Research Objectives Research Design Dataset Basic Bibliographic Analysis Content Map Analysis Citation Network Analysis Conclusions

3. 3 Introduction Nanotechnology –A fundamental technology. –Critical for a nation’s technological competence. –Revolutionizes a wide range of application domains. –Its R&D status attracts various communities’ interest. Patent analysis has been widely used to assess a field’s research and development status. –(Huang et al., 2003a, Huang et al., 2004 ) studied the longitudinal patent publications of different countries, institutions, and technology fields in the nanotechnology field. –(Huang et al., 2005) studied the impact of National Science Foundation’s funding on nanotechnology patents. Introduction

4. 4 Our previous research shows that: –The US is the main contributor to the nanotechnology field. –Japan and some European countries, such as Germany and the United Kingdom, play an important role in worldwide nanotechnology research. Many patent analysis studies are based on the patents filed in the US Patent and Trademark Office (USPTO) database. –Although the USPTO covers many of the patents in the nanotechnology field, the European Patent Office (EPO) and Japan Patent Office (EPO) also document large amounts of nanotechnology patents. Little research/information available about –The nanotechnology research status reflected by the patents in the EPO database and JPO database. –Comparisons of the characteristics of the patents filed in the three repositories. Introduction

5. 5 Our Research Our research focuses on the nanotechnology field and is a comparative study of nanotechnology patents filed in USPTO, EPO, and JPO. –The nanotechnology research in German, P. R. China, South Korea, and France are also very active. Their patent offices documented many nanotechnology patents (mostly in their own language). But in this research we focus on the patents documented in EPO and JPO, which have been translated into English. We use basic bibliographic analysis, content map analysis, and citation network analysis techniques. Introduction

6. 6 Patent Analysis Patent publication status has been used in evaluating technology development (Karki, 1997; Oppenheim, 2000; Narin, 1994) in different domains: –Nanotechnology field (Huang et al., 2003a; Huang et al., 2004; Huang et al., 2005) –Gastroenterology field (Lewison, 1998) –Taiwan high-tech companies (Huang et al., 2003b) Background and Research Objectives

7. 7 Patent Offices in the World There are several governmental (e.g., USPTO) or intergovernmental (e.g., EPO) patent offices which control the granting of patents in the world. USPTO, EPO and JPO issue nearly 90 percent of the world’s patents (Kowalski et al., 2003). –In the nanotechnology field, the United States, the European group, and Japan dominate the patent publication in the USPTO filed patents (Huang et al., 2003a). The inventors may file their patents in different patent offices. Background and Research Objectives

8. 8 Three Major Patent Offices USPTO Patents –US Patent and Trademark Office (USPTO): more than 6.5 million patents with 3,500 to 4,000 newly granted patents each week. EPO Patents –European Patent Office (EPO): more than 1.5 million patents with more than 1,000 newly granted patents each week. –European Patent Office provides an online patent search system, esp@cenet, which contains the structured patent information from EPO, JPO, USPTO, and other countries’ patent offices. JPO Patents –Japan Patent Office (JPO): more than 1.7 million patents with 2,000 to 3,000 newly granted patents each week. Background and Research Objectives

9. 9 Patent Offices’ Effect The patent offices have different procedures and policies which affect the patent publication process. –USPTO patents have more citations per patent due to the different rules governing citation practices (Bacchiocchi et al., 2004). In the USA, the “duty of candor” rule requires applicants to disclose all the prior related work of which they are aware. At the European Patent Office, there is no such rule. Most EPO patent citations were added by the examiners. –The USPTO has less rigorous patent applications standards than the EPO (Quillen et al., 2002). The USPTO has a significantly higher grant rate than EPO and JPO. Background and Research Objectives

10. 10 Patent Offices’ Effect (cont.) The “home advantage” effect can be another factor that affects the composition of the patents in one repository. –Domestic applicants, proportionate to their innovative activities, tend to file more patents with their home country patent office than foreign applicants do (European Commission, 1997). –Both EPO and USPTO patents have the home advantage effect (Criscuolo P, 2005). –The patents in USPTO, EPO, and JPO databases have the home advantage effect both in the whole dataset and in “high-tech” areas (Ganguli, 1998). Background and Research Objectives

11. 11 Utilizing Different Patent Offices’ Repositories To obtain a comprehensive understanding of a technology area’s development, it is necessary to study the patents filed in different patent offices’ repositories. Background and Research Objectives

12. 12 Utilizing Different Patent Offices’ Repositories In some other domains, a few previous studies combine different patent offices’ data for their research: –Balconi et al. (2004a; 2004b) studied Italian professors’ contribution in the firms in science-based technological classes using the patents filed in USPTO and EPO. –Lukach et al. (2001) studied inter-firm and intra-firm knowledge diffusion patterns using patents published in EPO and USPTO by Belgian Companies. In the nanotechnology field, many previous studies use a single patent repository. –Huang et al. (2003a, 2004) assessed nanotechnology research status from 1976 to 2003 using USPTO patents. –Meyer (2001) assessed the interrelationships between science and technology in the nanotechnology field using USPTO patents. Background and Research Objectives

13. 13 Research Gap Few studies employ multiple repositories to reveal the nanotechnology field’s R&D status. Results of past patent analysis studies may be biased by the characteristics of different databases. Background and Research Objectives

14. 14 Research Objectives Assess the nanotechnology development status represented by USPTO, EPO, and JPO patents. Compare and contrast the differences in the nanotechnology patents in the three repositories. Background and Research Objectives

15. 15 Patent parsing Research Design Data acquisition USPTO database USPTO database Research status analysis Topic coverage Collected by keywords Content map Citation Network Patent publication Patent importance/ strength of a repository Patent importance/ strength of a repository Number of patents Average number of cites EPO database EPO database JPO database JPO database Knowledge diffusion Collected by keywords JPO dataset EPO dataset USPTO dataset Patent status checking EPO+JPO patent JPO patent Patent status We develope a framework to assess the R&D status of a a science and engineering domain based on the patents in the three repositories: USPTO, EPO, and JPO. Research Design

16. 16 Research Design The framework contains three steps: –Data acquisition Retrieve patents from the three repositories. –Patent parsing Parse the free-text data to structured data. –Research status analysis Analyze the patents at different analytical unit levels, i.e., country (country group), assignee institution, and technology field (represented by third level IPC categories). Research Design

17. 17 Data Acquisition Retrieve the patents from the three repositories –A list of keywords can be used to search for patents related to a domain from the three repositories. –USPTO USPTO provides online full-text access for patents issued since 1976. The patents can be searched using almost all the data fields of a patent. –EPO esp@cenet provides online full-text access to EPO patents issued since 1978. The patents can be searched based on title, abstract, and some of the bibliographic data. –JPO Patent Abstracts of Japan (PAJ) is the official patent database of JPO, which contains the patents issued since 1976. The PAJ database is difficult to spider. But its patents and patent applications can be searched from esp@cenet. Need to use the PAJ database to differentiate granted patents from patent applications. Research Design

18. 18 Research Status Analysis We assess a field’s research status using the following indicators. Patent publication trend –Number of patents by country in each year –Number of patents by country group in each year –Number of patents by assignee institution in each year –Number of patents by technology field in each year Patent impact –Average number of cites by country –Average number of cites by assignee institution –Average number of cites by technology field Topic coverage –Content map analysis Knowledge diffusion –Country citation network analysis –Institution citation network analysis –Technology field network analysis Research Design

19. 19 Data Limitations The three repositories have different data fields, which need to be considered during the analysis. –There is no assignee country information in JPO patents. We can't perform the "assignee country analysis" and "country group analysis" on the JPO patents. –There is no citation information in JPO patents. We can't perform the citation network analysis on the JPO patents. –In previous studies we used US Patent Classifications to represent technology fields. Since USPTO, EPO, and JPO all have International Patent Classification (IPC), in this research we use IPC classifications to represent technology fields. The United States Patent Classification has 462 first-level categories. IPC has 120 level-2 classifications and 631 level-3 classifications. To be comparable to our previous research, we use level-3 IPC in this study. Research Design

20. 20 Analysis Performed USPTOEPOJPO Patent publication trend Number of patents by country in each year  No Number of patents by country group in each year  No Number of patents by assignee institution in each year  Number of patents by technology field in each year  Patent impact Average number of cites by country  No Average number of cites by assignee institution  No Average number of cites by technology field  No Topic coverage Content map analysis  Knowledge diffusion Country citation network analysis  No Assignee institution citation network analysis  No Technology field network analysis  No Research Design

21. 21 Data Collection Keyword list –A nanotechnology-related keyword list provided by domain experts (Huang et al., 2003; 2004). Patent search/retrieval –In our previous research, we retrieved nanotechnology patents by searching the nanotechnology-related keyword list in patent title, abstract, and claims (“title-claims” search) and in all patent data fields (“full-text” search) from USPTO database (Huang et al., 2003; 2004). –Because of the limitation of the search function of esp@cenet, we collected the nanotechnology patents in EPO and JPO by searching the nanotechnology-related keyword list in patent title and abstract (“title-abstract” search). –To be comparable with the patents retrieved from EPO and JPO, we collected the data using “title-abstract” search from USPTO database in this research. Dataset

22. 22 Data: USPTO Patents Comparing with "full-text" search and "title-claims" search, “title- abstract” search provides fewer search results but with higher accuracy. From “title-abstract” search: –5,363 unique patents were collected. –Submitted by 2,196 assignee institutions, 8,405 inventors, and 46 countries. Dataset

23. 23 Data: USPTO Patents (cont.) Top 20 nanotechnology patent assignees (with average patent age) and countries based on “title-abstract” search of patents published from 1976 to 2004 Dataset

24. 24 Data: EPO Patents EPO nanotechnology patent collected by “title-abstract” search in esp@cenet. –2,328 EPO patents were collected. –Submitted by 1,168 assignee institutions, 5,400 inventors, and 43 countries. Dataset

25. 25 Data: EPO Patents (cont.) Top 20 nanotechnology patent assignees (with average patent age) and countries based on “title-abstract” search of patents published from 1978 to 2004 Dataset

26. 26 Data: JPO Patents JPO patent collection –The patents collected by “title-abstract” search in esp@cenet contain both JPO patent applications and JPO registered patents. –The patents’ status are retrieved from the JPO database to filter out patent applications. –923 JPO registered patents were collected. –Submitted by 348 assignee institutions and 1,729 inventors. Dataset

27. 27 Data: JPO Patents (cont.) Top 20 nanotechnology patent assignees based on “title- abstract” search of patents published from 1976 to 2004 Dataset

28. 28 Data: USPTO, EPO, and JPO Patents The numbers of nanotechnology patents in USPTO and EPO roughly show a pattern of straight line, indicating exponential increases of the nanotechnology patents. After 1993, the number of nanotechnology patents published in JPO becomes stable. Dataset The numbers of nanotechnology patents published in USPTO, EPO and JPO by year (log scale)

29. 29 I. Basic Analysis- USPTO Patents by Country Top 20 nanotechnology patent assignee countries in USPTO (“title-abstract” search) and their patents by year, 1976-2004 (log scale) Many countries had an increasing trend of nanotechnology patent publication The United States published more nanotechnology patents than other countries in USPTO. The US nanotechnology patents showed an exponential growth trend. Between 1994 and 2002, Japan nanotechnology patents showed a slower increasing speed. Germany patents in USPTO were continuously increasing. After 2002, the number of nanotechnology patents published by France experienced a decrease. Basic Bibliographic Analysis

30. 30 Basic Analysis- EPO Patents by Country The United States filed more nanotechnology patents than other countries. The US nanotechnology patents showed an exponential increase trend. The Japan patents kept at the same level between 1989 and 2000. After 2000, there was a rapid growth of Japan patents. Germany patents remained at the same level after 2000. France patents were consistently increasing in EPO. Top 20 nanotechnology patent assignee countries in EPO (“title-abstract” search) and their patents by year, 1978-2004 (log scale) Basic Bibliographic Analysis

31. 31 Basic Analysis- USPTO Patents by Country Group Assignee country group analysis by year, 1976-2004 (“title-abstract” search) (log scale) The United States filed more patents than the other three groups. The European Group, Japan, and the Others group had similar numbers of nanotechnology patents in each year. Basic Bibliographic Analysis

32. 32 Basic Analysis- EPO Patents by Country Group Assignee country group analysis by year, 1978-2004 (“title-abstract” search) (log scale) The numbers of patents filed by the United States and European group countries were at the same level. The numbers of patents filed by Japan and Other countries were at the same level after 1998. These two groups’ patents are fewer than the patents filed by the other two country groups. Basic Bibliographic Analysis

33. 33 Findings - Patents by Country and Country Group USPTO and EPO assignee country analysis: –Many of the top 20 assignee countries had an increasing trend of nanotechnology patent publication. –The United States filed more nanotechnology patents than other countries. Its patents showed an exponential increasing trend. –Some countries showed different publication trends in the two repositories. USPTO and EPO assignee country group analysis: –In USPTO, the United Sates published more patents than the other three country groups. –In EPO, the United Sates published a similar number of patents to European group countries. –The United States filed much more nanotechnology patents in USPTO than in EPO. –European group countries filed more patents in EPO than in USPTO. Basic Bibliographic Analysis

34. 34 Basic Analysis- USPTO Patents by Assignee Top 10 nanotechnology patent assignee institutions in USPTO (“title-abstract” search) and their patents by year, 1976-2004 Most of the top assignees were United States companies/ institutions. Some institutions, such as IBM and “Micron Technology, Inc” showed a decrease in recent years’ nanotechnology patent publication. Most institutions started publishing nanotechnology patents in 1990s, while IBM, “The United States of America as represented by the Secretary of the Navy,” “Eastman Kodak Company,” and “Minnesota Mining and Manufacturing Company” started in 1970s. Basic Bibliographic Analysis

35. 35 Basic Analysis- EPO Patents by Assignee The top 10 assignees consisted of companies/institutions from the United States, Koreas, Japan, etc. “Samsung Electronics Co Ltd” had a steady increase in patent publication after 2001 Some institutions, such as “Eastman Kodak Co” and “Japan Science & Tech Corp” experienced a decrease in recent years. Top 10 nanotechnology patent assignee institutions in EPO (“title-abstract” search) and their patents by year, 1978-2004 Basic Bibliographic Analysis

36. 36 Basic Analysis- JPO Patents by Assignee Top 10 nanotechnology patent assignee institutions in JPO (“title-abstract” search) and their patents by year, 1976-2004 Most of the top assignees were Japanese companies/ institutions. Many of assignee institutions in JPO experienced a decrease in recent years, such as “Nippon Electric Co,” “Agency Ind Science Techn,” “Tokyo Shibaura Electric Co,” etc. “Japan Science & Tech Corp” and “Nat Inst for Materials Science” continued to have active patent publications in recent years. Basic Bibliographic Analysis

37. 37 Findings - Patents by Assignee “Home advantage” effect: –In the three patent databases, many of the top nanotechnology patent assignee institutions are companies that belong to the same region as the patent office. Basic Bibliographic Analysis

38. 38 Basic Analysis- USPTO Technology Fields Top 10 technology fields according to the number of patents published between 1976 and 2004 based on US Class (“title-abstract” search) Basic Bibliographic Analysis

39. 39 Basic Analysis- USPTO Technology Fields Top 10 US classification technology fields by year (1976-2004) (“title- abstract” search) Most of the top 10 technology fields had an increasing trend of patent publication. Comparing with other technology fields, the number of patents in technology field “250: Radiant energy” did not change much after 1989. Technology field “257:Active solid-state devices” experienced a rapid growth since 1999. Basic Bibliographic Analysis

40. 40 Basic Analysis- USPTO Technology Fields Top 10 technology fields according to the number of patents published between 1976 and 2004 based on IPC (“title-abstract” search) Basic Bibliographic Analysis Technology field “H01L” had the most nanotechnology patents published, almost double the amount of the second largest technology field “A61K.”

41. 41 Basic Analysis- USPTO Technology Fields Top 10 IPC technology fields by year (1976-2004) (“title-abstract” search) Most of the top 10 technology fields had an increasing trend of patent publication. The technology fields “H01L: Semiconductor devices; electric solid state devices” experienced much faster growth than other technology fields. The patents published in technology field “A61K: Preparations for medical, dental, or toilet purposes” each year became stable after 1996. Some of the technology fields in the two systems have similar meanings and similar development trends, for example, H01L in IPC and 438 in USPC. Basic Bibliographic Analysis

42. 42 Basic Analysis- EPO Technology Fields Top 10 technology fields according to the number of patents published between 1978 and 2004 (“title-abstract” search) Basic Bibliographic Analysis

43. 43 Basic Analysis- EPO Technology Fields Top 10 technology fields by year (1978-2004) (“title-abstract” search) Most of the top 10 technology fields had an increasing trend of patent publication. After 2000, technology fields “A61K: Preparations for medical, dental, or toilet purposes,” “H01L: Semiconductor devices; electric solid state devices,” and “C01B: Non-metallic elements; compounds thereof" showed faster growth than the other technology fields. The patent publication of technology field “G01B: Measuring length, thickness, or similar linear dimensions; measuring angles; measuring areas; measuring irregularities of surfaces or contours” was quite consistent in recent years, which is different from the other technology fields. Basic Bibliographic Analysis

44. 44 Basic Analysis- JPO Technology Fields Top 10 technology fields according to the number of patents published between 1976 and 2004 (“title-abstract” search) Basic Bibliographic Analysis

45. 45 Basic Analysis- JPO Technology Fields Top 10 technology fields by year (1976-2004) (“title-abstract” search) Many of the technology fields experienced a decrease in recent years. Technology field “C01B: Non-metallic elements; compounds thereof” had a steady growth in patent publication. Basic Bibliographic Analysis

46. 46 Summary: USPTO/EPTO/JPO Technology Fields Basic Bibliographic Analysis The three repositories have several top technology fields in common, e.g., “A61K,” “H01L,” “H01J,” “G01B,” and “G01N.” Although the top 10 technology fields are very similar in the three repositories, their rankings (and numbers of patents published) are significant different.

47. 47 Findings - Technology Fields In USPTO, technology field H01L had many more nanotechnology patents than other fields. In EPO and JPO there was no dominate technology field among the top 10 technology fields. USPTO, EPO and JPO have many top technology fields in common. Most of the JPO top technology fields experienced a decrease in recent years, which was different from the technology fields in USPTO and EPO. In USPTO patents, the top technology fields were mainly related to biomedical research, material research and semiconductor research. In EPO patents, the top technology fields were mainly related to biomedical research, chemistry research, material research, and semiconductors research. In JPO patents, the top technology fields were mainly related to biomedical research and material research and semiconductor research. Basic Bibliographic Analysis

48. 48 Basic Analysis- Average Number of Cites by Country USPTO top 10 countries with more than 10 patents based on the average number of cites measure (1976-2004) (“title- abstract” search) EPO top 10 countries with more than 10 patents based on the average number of cites measure (1978-2004) (“title- abstract” search) Basic Bibliographic Analysis

49. 49 Basic Analysis- Average Number of Cites by Assignee Institution USPTO top 10 assignee institutions with more than 10 patents based on the average number of cites measure (1976-2004) (“title-abstract” search) EPO top 10 assignee institutions with more than 10 patents based on the average number of cites measure (1978-2004) (“title-abstract” search) Basic Bibliographic Analysis

50. 50 Basic Analysis- Average Number of Cites by Technology Field USPTO top 10 technology fields with more than 10 patents based on the average number of cites measure (1976- 2004) (“title- abstract” search) EPO top 10 technology fields with more than 10 patents based on the average number of cites measure (1978- 2004) (“title- abstract” search) Basic Bibliographic Analysis

51. 51 Findings - Average Number of Cites In general, USPTO countries, assignees, and technology fields had a higher average number of cites than those in EPO. –USPTO requires inventors to cited previous works in their patents. –EPO patent citations were mostly assigned by the examiners. Although five out of the ten highly cited countries (The United Sates, Japan, Switzerland, France, and Israel) are the same in USPTO and EPO, their rankings are significantly different. –The United States and Japan published most of the patents with very high average number of cites in both repositories. The difference between USPTO and EPO highly cited technology fields shows the different focuses and strengths of the nanotechnology patents in the two repositories. However, technology fields “H01J” and “G01B” appear in both top 10 lists with large numbers of patents and high average number of cites. Basic Bibliographic Analysis

52. 52 II. Content Map Analysis Documents Topic Similarity Keyword Extraction Topics Visualization Arizona Noun Phraser Topic Relation Analysis SOM Algorithm Technology topics,represented by keywords in the documents, are extracted using a Natural Language Processing tool, the Arizona Noun Phraser, which can identify the key noun phrases based primarily on the linguistic patterns of free texts. The technology topics map are organized by the multi-level self-organization map algorithm (Chen et al., 1996; Ong et al., 2005) developed by the Arizona Artificial Intelligence Lab. This algorithm calculates the topic similarities according to the co-occurrence patterns of key phrases in document titles and abstracts. The topics are positioned geographically on a graph according to their similarity by the topic map interface. Content Map Analysis

53. 53 Topic Map Interface Two components –A folder tree –A hierarchical content map Each node in the tree, corresponding to a region in the map, is a topic (keyword) identified from the document. Conceptually closer technology topics were positioned closer geographically. Numbers of documents that were assigned to the different levels of topics are presented after the topic labels. The sizes of the topic regions also generally correspond to the number of documents assigned to the topics. Content Map Analysis

54. 54 Content Map Analysis (USPTO) USPTO Content Map (1976-1989) (“title-abstract” search) Content Map Analysis

55. 55 Content Map Analysis (USPTO) USPTO Content Map (1990-1999) (“title-abstract” search) USPTO Content Map (2000-2004) (“title-abstract” search) Content Map Analysis 4.18 5.39 6.03 6.51 6.93 7.33 7.75 8.23 8.86 9.32 10.07 NEW REGION -0.80 0.41 1.05 1.53 1.95 2.35 2.77 3.25 3.88 4.34 5.09 NEW REGION

56. 56 Findings –Content Map (USPTO) From 1976 to 1989, the major research topics of USPTO nanotechnology patents included: “carbon atoms,” “optical fibers,” and “thin films.” From 1990 to 1999, several new research topics appeared from 1990 to 1999, including: “aqueous solutions,” “composite materials,” “laser beams,” “nucleic acids,” “optical waveguide,” “organic colvents,” “reverse osmosis,” “self-assembled monolayer,” “semiconductor substrate,” “silicon carbide,” and “substrate surfaces.” From 2000 to 2004, the numbers of patents related to several topics had increased significantly, such as “aqueous solutions,” “composite materials,” “carbon nanotubes,” “nucleic acids,” “self-assembled monolayer,” and “thin films.” Some new topics also became major research topics in this time period, such as “atomic force microscope,” “clay materials,” “dielectric layers,” “nanocomposite materials,” “naphtha stream,” “polymeric materials,” and “semiconductor devices.” Content Map Analysis

57. 57 Content Map Analysis (EPO) -1.88 -0.67 -0.04 0.44 0.86 1.26 1.68 2.16 2.80 3.26 4.01 NEW REGION EPO Content Map (1990-1999) (“title-abstract” search) EPO Content Map (2000-2004) “title-abstract” search Content Map Analysis

58. 58 Findings –Content Map (EPO) From 1978 to 1989, EPO had only 97 nanotechnology patents, which are not enough to generate a meaningful content map. From 1990 to 1999, EPO nanotechnology patents covered the topics “aqueous solutions,” “atomic force,” “carbon nanotubes,” “magnetic core,” “metal oxides,” and “thin films.” From 2000 to 2004, the research topics “aqueous solutions,” “metal oxides,” and “thin films” had significant increase. The new topics included: “gate electrode,” “low dielectric,” “nanocomposite materials,” “nanoparticulate compositions,” and “ploymer compositions.” Content Map Analysis

59. 59 Content Map Analysis (JPO) -3.33 -2.12 -1.48 -1.00 -0.58 -0.18 0.24 0.72 1.35 1.82 2.56 NEW REGION JPO Content Map (1990-1999) (“title-abstract” search)JPO Content Map (1999-2004) (“title-abstract” search) Content Map Analysis

60. 60 Findings –Content Map (JPO) From 1978 to 1989, JPO had only 31 nanotechnology patents, which are not enough to generate a meaningful content map. From 1990 to 1999, the major topics of JPO nanotechnology patents were “atomic force microscope,” “laser beams,” “silicon substrate,” and “thin films.” From 2000 to 2004, the topics “atomic force microscope,” and “thin films” were still major research topics. The new research topics include “Carbon nanofibers,” “gate electrodes,” “heat treatment,” and “quantum dots.” Content Map Analysis

61. 61 Findings –Content Map USPTO patents had broader topic coverage than EPO and JPO. Many of the EPO and JPO topics were related to research tools/methods (e.g., “atomic force microscope,” “thin films,” and “scanning tunneling microscope”) and physics research (e.g., “carbon nanotubes,” “carbon nanofibers,” “magnetic core,” “metal oxides,” and “transition metal”) Many USPTO topics were related to physics research (e.g., “carbon nanotubes,” “laser beams,” “optical waveguide,” and “self-assembled monolayer”), biomedical research (e.g., “nucleic acids,” “organic colvents,” “pharmaceutical compositions,” and “reverse osmosis”), and electronic research (e.g., “dielectric layers,” “semiconductor devices” and “semiconductor substrate”). Content Map Analysis

62. 62 III. Citation Network Analysis In this research, the patent citation networks are studied at three abstract analytical unit levels: countries, institutions, and technology fields. In this research, the top 100 links of each network (according to the number of citations between the nodes) are used to create the core networks. These citation networks are visualized using an open source graph drawing software, Graphviz, provided by AT&T Labs (Gansner and North, 2000) (available at: http://www.research.att.com/sw/tools/graphviz/). In the citation networks, direction of the links represents the direction of the citations. For example, a link from “Country A” to “Country B” means that country A’s patents cited country B’s patents and the number beside the link is the total number of these citations. It allows us to identify the salient knowledge diffusion patterns among the analytical units. Citation Network Analysis

63. 63 Citation Network Analysis- USPTO Countries Citation Network Analysis

64. 64 Citation Network Analysis- EPO Countries Citation Network Analysis

65. 65 Findings – Country Citation Network In the USPTO dataset, the United States is the most significant citation center on the network. Japan, Republic of Korea, the United Kingdom, China (Taiwan) and Germany are the secondary citation centers and constructed a cluster with close citations. In the EPO dataset, the United States, France, Japan, Germany, and the United Kingdom are large citation centers and construct a citation cluster on the network. In both repositories, the countries have close citation relationships. In EPO most assignee countries have more than one citing/cited country. In USPTO several countries only have citation relationship with the United States. Many of the countries that only had citations with the United States were relatively new in the nanotechnology domain. Citation Network Analysis

66. 66 Citation Network Analysis- USPTO Institutions Citation Network Analysis

67. 67 Citation Network Analysis- EPO Institutions Citation Network Analysis

68. 68 Findings – Institution Citation Network Both institution citation networks have many disconnected components. In USPTO, “IBM,” “Massachusetts Institute of Technology,” “The Regents of the University of California,” and “Molecular Imaging Corporation” are the major companies/institutions in the largest citation cluster. In EPO, “IBM,” “Hitachi Europ Ltd,” “Seiko Instr Inc,” “Matsushita Electric Ind Co Ltd,” etc. are the major citation centers in the first citation cluster. “Lucent Technologies Inc”, “Iljin Nanotech Co Ltd”, “Ise Electronics Corp,” etc. construct the other a large citation cluster. Citation Network Analysis

69. 69 Citation Network Analysis- USPTO Technology Fields (US class) Citation Network Analysis

70. 70 Citation Network Analysis- USPTO Technology Fields (IPC) Citation Network Analysis

71. 71 Citation Network Analysis- EPO Technology Fields Citation Network Analysis

72. 72 Findings – Technology Field Citation Network In all three technology field citation networks, the technology fields have close citation relationships. In the USPTO technology field citation network represented by USPC, the technology fields that are most often citing and being cited by other fields were “435 Chemistry: molecular biology and microbiology,” “428 Stock material or miscellaneous articles,” and “427 Coating processes.” In USPTO, the large citation centers of technology fields represented by IPC include “H01L: Semiconductor devices; electric solid state devices not otherwise provided for,” “G01N: Investigating or analysing materials by determining their chemical or physical properties,” “B32B: Layered products, i.e. products built-up of strata of flat or non-flat, e.g. cellular or honeycomb, form,” and “H01J: Electric discharge tubes or discharge lamps.” Citation Network Analysis

73. 73 Findings – Technology Field Citation Network (cont.) In EPO, technology fields “H01J: Electric discharge tubes or discharge lamps,” “C08K: Use of inorganic or non- macromolecular organic substances as compounding ingredients,” “C09D: Coating compositions, e.g. paints, varnishes, lacquers; filling pastes; chemical paint or ink removers; inks; correcting fluids; woodstains; pastes or solids for colouring or printing; use of materials therefor,” and “C01B: Non-metallic elements; compounds thereof” are major citation centers in the technology field citation network. In USPTO technology field citation network, a major citation center usually has citation relationships with several smaller citation centers. On the other hand, in EPO, most citation relations are between the major citation centers. Citation Network Analysis

74. 74 Conclusions The nanotechnology patents issued by USPTO and EPO experienced an exponential growth in the past 30 years. But the nanotechnology patent issued by JPO yearly became stable after 1993. In USPTO and EPO, the high productivity assignee countries and their rankings are very similar to each other. The United States filed the most nanotechnology patents in both repositories. The patent published by the four country groups all had an increasing trend in both USPTO and EPO. –The United States had much more nanotechnology patents than the other three groups in USPTO. –European group countries had similar number of patents as the Untied States in EPO. Conclusions

75. 75 Conclusions The top assignee institutions are quite different in USPTO, EPO, and JPO. However, IBM and “L’Oreal” are high productivity assignee institutions in all three repositories. Most of the top assignee institutions in USPTO and JPO are United States institutions and Japan institutions, respectively. From the content map analysis, USPTO patents cover more topic areas than EPO and JPO. –Many of the EPO and JPO topics were related to research tools/methods and physics research. –Many of the USPTO topics were related to physics research, biomedical research, and electronic research. Both USPTO and EPO assignee country citation networks have close citation relationships. The USPTO technology field citation network shows a clear pattern of knowledge diffusion from the major citation centers to the smaller citation centers. The EPO technology field citation network shows a clear pattern of knowledge exchange between the major citation centers. Conclusions

76. 76 Future Directions Study the inter-repository citation relationships of the three repositories. –At the repository level –At the technology field level Study the collaboration of the inventors in the three repositories. –At the country level –At the assignee level Extend our research framework to include the more patent offices’ documents, such as Germany, P. R. China, South Korea, and France.

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