PERSPECTIVES

Trends in worldwide nanotechnology patent applications:

1991 to 2008

Yan Dang • Yulei Zhang • Li Fan •

Hsinchun Chen • Mihail C. Roco

Received: 7 December 2009 / Accepted: 10 December 2009

 Springer Science+Business Media B.V. 2009

Abstract Nanotechnology patent applications published during 1991–2008 have been examined using

the ‘‘title–abstract’’ keyword search on esp@cenet

‘‘worldwide’’ database. The longitudinal evolution of

the number of patent applications, their topics, and

their respective patent families have been evaluated for

15 national patent offices covering 98% of the total

global activity. The patent offices of the United States

(USA), People’s Republic of China (PRC), Japan, and

South Korea have published the largest number of

nanotechnology patent applications, and experienced

significant but different growth rates after 2000. In

most repositories, the largest numbers of nanotechnology patent applications originated from their own

countries/regions, indicating a significant ‘‘home

advantage.’’ The top applicant institutions are from

different sectors in different countries (e.g.,

from industry in the US and Canada patent offices,

and from academe or government agencies at the PRC

office). As compared to 2000, the year before the

establishment of the US National Nanotechnology

Initiative (NNI), numerous new invention topics

appeared in 2008, in all 15 patent repositories. This is

more pronounced in the USA and PRC. Patent families

have increased among the 15 patent offices, particularly after 2005. Overlapping patent applications

increased from none in 1991 to about 4% in 2000 and

to about 27% in 2008. The largest share of equivalent

nanotechnology patent applications (1,258) between

two repositories was identified between the US and

Japan patent offices.

Keywords Nanotechnology  Research and

development  esp@cenet ‘‘worldwide’’ database 

Number of patent applications  Longitudinal

evolution  Patent topics  Patent family analysis

Introduction

Nanotechnology developments continue to be produced at exponential rates for a wide and diverse

range of applications. Because of nanotechnology’s

pivotal role in future scientific and economic development, in order to remain competitive, more than 60

countries have adopted national projects or programs

Y. Dang (&)  Y. Zhang  L. Fan  H. Chen

Department of Management Information Systems, Eller

College of Management, The University of Arizona,

Tucson, AZ 85721, USA

e-mail: ydang@email.arizona.edu

Y. Zhang

e-mail: ylzhang@email.arizona.edu

L. Fan

e-mail: fanli@email.arizona.edu

H. Chen

e-mail: hchen@eller.arizona.edu

M. C. Roco

National Science Foundation, 4201 Wilson Blvd.,

Arlington, VA 22230, USA

e-mail: mroco@nsf.gov

123

J Nanopart Res

DOI 10.1007/s11051-009-9831-7
to prompt research in nanotechnology since 2000

(Roco 2005). Patent analysis is an indicator for

assessing development of different research communities and technology fields (Narin 1998; Oppenheim

2000). Our evaluation framework integrates bibliographic, citation (Garfield 1955), contents (Tolle and

Chen 2000), network (Albert and Barabasi 2002), and

statistical analyses. The framework has been applied

to nanotechnology patent publications in the US

Patent and Trademark Office (USPTO), the European

Patent Office (EPO), and the Japan Patent Office

(JPO) in Huang et al. (2003) (for USPTO), Huang

et al. (2006) (for USPTO), and Li et al. (2007) (for

USPTO, EPO, and JPO).

This study has considered all the public repositories

and is focused on data from the 15 countries’/regions’

repositories that are most active in the nanotechnology

domain; these repositories cover 98% of the patent

applications worldwide. The respective applications

were searched on titles and abstracts (‘‘title–abstract’’

search) using a group of keywords provided by domain

experts (Huang et al. 2003). This article presents the

longitudinal evolution of the number of patent applications after their origin, topics, and corresponding

patent families since 1991.

Analysis method of patent applications

Data collection and preprocessing

Nanotechnology publications from different countries’/regions’ patent offices (repositories) were

extracted from the esp@cenet ‘‘worldwide’’ database

into our database by using keyword ‘‘title–abstract’’

searching.

A patent office is a governmental or intergovernmental organization which controls the issue of

patents. Different countries have their own patent

offices, such as the USPTO, the JPO, the Canadian

Intellectual Property Office (CIPO), and the South

Korean Intellectual Property Office (KIPO). In addition to national (country level) patent offices, there are

several regional (country group level) patent offices as

well, such as the EPO and the World Intellectual

Property Organization (WIPO). The EPO grants

European patents for the 27 member states of the

European Patent Convention. The WIPO is a specialized agency of the United Nations with 184 member

states in 2008. It grants patents for all of its member

states. Many countries publish patent applications and/

or grant patent rights for public information (Chemical

Abstracts Service 2008).

A reliable international database covering patent

information from multiple patent offices is the esp@

cenet ‘‘worldwide’’ database, which is maintained by

the EPO together with the member states of the

European Patent Organization. Esp@cenet includes

three databases:

– ‘‘EPO’’ database

– ‘‘WIPO’’ database

– ‘‘worldwide’’ database

The esp@cenet ‘‘worldwide’’ database contains

the patent applications examined and published by 85

individual countries’/regions’ patent offices, including the USPTO, EPO, and JPO. The esp@cenet

‘‘worldwide’’ database holds more than 60 million

patents (Espacenet Website, ‘‘Coverage of the worldwide database’’) (Espacenet Website, ‘‘Coverage of

the worldwide database’’) (EPO 2008). English

translations for all other languages are provided for

the bibliographic information, and selected content

information (such as abstract, claim, and description)

are also provided. Owing to the limitation of the

search functions of esp@cenet, we collected the

patent applications by searching the nanotechnology

keywords only in each patent application’s title and

abstract (‘‘title–abstract’’ search).

The esp@cenet ‘‘worldwide’’ database previously

has been used to examine patents in biology (Oldham

and Cutter 2006), hydrogen and fuel cells (Seymour

et al. 2007), and globalization of knowledge (Andersen

et al. 2006).

Patent parsing

Two sets of patent information were parsed into our

database from the collected patent applications:

– Nanotechnology patent applications published in

different countries’/regions’ patent offices (repositories)

– Patent family information of these patent applications.

Table 1 shows the data field limitation of our patent

application collection. Most of the data fields are

available in the esp@cenet ‘‘worldwide’’ database.

J Nanopart Res

123
However, it does not contain the citation information

for patent applications published in patent offices other

than EPO and WIPO (Espacenet Website, ‘‘What is a

cited document?’’). For some regional or country

patent offices, the bibliographic data (such as the

application country, European patent classification

code (EPC), claim, or description) are incomplete. All

the selected repositories in our study are part of EPO

and WIPO.

A patent application for an invention is originally

filed in one country; however, it can be filed later in

other countries as well. The original, first application

filing generally is considered to be the priority

application (Hingley and Park 2003). In esp@cenet,

such related applications or ‘‘members of corresponding documents’’ or ‘‘equivalents’’ and have exactly

the same priority (Espacenet Website, ‘‘Also published as documents’’).

A patent family is a group of patents that are all

related to each other. We use the esp@cenet patent

‘‘simple family’’ definition as comprising all the

documents having exactly the same priority or combination of priorities (Espacenet Website, ‘‘Patent

families’’). The International Patent Documentation

Center (INPADOC) defines as ‘‘expanded family’’ all

the documents sharing directly or indirectly (e.g., via a

third document) at least one priority (Espacenet

Website, ‘‘Patent families’’).

Data analysis

Three types of analyses were conducted using the

data collected from the previous components:

– Longitudinal evolution of the number of patent

publications per year and per applicant (i.e., the

institution to which a patent is assigned to countries, applicant institutions, and technology fields)

– Topic analysis, where we have created content

maps to identify the most important and emerging

research topics in nanotechnology domain in

different time intervals for each patent office

(repository).

– Patent family analysis across different patent offices

(repositories) including ranking those with the

largest numbers of equivalent patent applications.

Results

Data description

We collected the nanotechnology patent applications

published from 1991 to 2008 from the esp@cenet

‘‘worldwide’’ database. We focused attention on the

leading 15 country/regional patent offices that cover

more than 98% of the whole collection; each has

more than 100 patent applications.

Longitudinal evolution of patent applications

Global increase of nanotechnology patents

The evolution of the total number of nanotechnology

patent applications in the 15 repositories per year

from 1991 to 2008 is shown in Fig 1. This figure also

shows the number of non-overlapping nanotechnology patent applications by considering one patent

application per family. The annual rate of increase

for all the patent publications is more pronounced

between 2000 and 2008 (34.5%). This rate is higher

than that of Science Citation Index’s article publication rate of 20–25% for the same period when we use

the same keyword ‘‘title–abstract’’ search approach as

for patent applications.

The percentage of nanotechnology patent application

as compared to the total number of patent applications in

all the technical areas is illustrated in Fig. 2.

Table 1 Data field limitation of the esp@cenet ‘‘worldwide’’

database

Data field Available

Publication number Yes

Publication date Yes

Inventor name Yes

Applicant institution name Yes

Applicant country *

International patent classification code (IPC) Yes

European patent classification code (EPC) *

Citation information No

Priority number(s) Yes

Title Yes

Abstract Yes

Claim *

Description *

* The patent application data from some countries/regions’

patent offices is incomplete

J Nanopart Res

123
The nanotechnology patent application percentages for the USPTO reported in the above figure are

consistent with the data trends reported in previous

studies (Huang et al. 2006; Hu et al. 2007) where the

granted patents were searched by ‘‘title–claims’’ from

1991 to 2004. In that study, the percentage of granted

patents reached 1.09% in 2004 versus 0.63% for

patent applications in Fig. 2. Our previous studies

also showed that the nanotechnology-granted patent

percentages for ‘‘full-text’’ search was 4.85% in 2004

for the USPTO.

Number of patent applications per repository

Table 2 lists the numbers of nanotechnology patent

applications published by each of the 15 countries/

Total number of nanotechnology applications per year

0

2,000

4,000

6,000

8,000

10,000

12,000

14,000

199119921993

1994

1995199619971998

1999

200020012002

2003

20042005200620072008

Year

Number of Patent Applications

All applications

Non-overlapping applications Year All applications Non-overlapping 

applications

1991 224 224 

2000 1,197 1,153 

2008 12,776 10,067 

Fig. 1 Longitudinal

evolution of the total

number of nanotechnology

patent applications in the 15

repositories per year (‘‘title

abstract,’’ 1991–2008)

The percentage of nanotechnology patent application as compared to the total number of 

patent applications in all technical areas

0.0%

0.2%

0.4%

0.6%

0.8%

1.0%

1.2%

1991

19921993

1994

1995

1996

1997

199819992000

2001

200220032004

200520062007

2008

Year

Percentage

All 15 repositories USPTO (the United States' patent office)

Fig. 2 Longitudinal

evolution of the percentage

of patent publications on

nanotechnology versus all

topics, in the repositories of

leading 15 countries/regions

and USA from 1991 to 2008

using keyword ‘‘title–

abstract’’ search

J Nanopart Res

123
regions’ patent offices from 1991 to 2008. The

USPTO examined and published the largest number

of nanotechnology patent applications, followed by

the patent offices of the PRC and Japan.

The total number of nanotechnology patent applications published from 1991 to 2008 by authors from

the US and PRC are estimated each at over 17,000.

Over 20% of the US patent applications and 4% of

the PRC’s are in foreign repositories.

Figures 3 and 4 show the evolution of the numbers

of nanotechnology patent applications published in

different countries’/regions’ patent offices by year.

Since the patent offices of the US, PRC, Japan, and

South Korea had many more nanotechnology patent

applications, we present their evolution trends in

Fig. 3. The evolution trends of the other 11 countries’/regions’ patent offices are shown in Fig. 4.

The patent offices of the US, PRC, Japan, and South

Korea have significantly more nanotechnology patent

applications than other patent offices, and all experienced larger increases especially after 2003. The

PRC’s repository surpassed the USA’ repository after

2006. As shown in Fig. 4, the other 11 patent offices

have experienced mostly increases but also decreased

in recent years. The patent offices of the Russian

Federation, Brazil, and the United Kingdom (UK)

reached their peaks in 2008 with 162, 103, and 68

nanotechnology patent applications, respectively. The

Ukraine’s patent office peaked in 2007 with 87

nanotechnology patent applications, and the patent

offices of Germany and New Zealand reached their

peaks in 2006 with 164 and 21 nanotechnology patent

applications, respectively. Canada’s and Mexico’s

patent offices reached their peaks in 2005 with 274 and

94 nanotechnology patent applications, respectively.

Australia’s and France’s patent offices peaked in 2003

with 343 and 57 nanotechnology patent applications,

respectively. Taiwan’s patent office had more than 200

nanotechnology patent applications per year from

Table 2 Nanotechnology

patent applications

published in the top 15

countries/regions’ patent

offices in the interval 1991

to 2008 using keyword

‘‘title–abstract’’ search

Rank Patent office

(repository)

No. of nanotechnology

patent applications (1991–2008)

2000 2008

1 USA 19,665 405 3,729

2 PRC 18,438 105 5,030

3 Japan 10,763 328 1,744

4 South Korea 5,963 74 1,249

5 Canada 1,539 41 255

6 Taiwan 1,363 28 3

7 Germany 1,312 62 70

8 Australia 1,296 76 136

9 Russian Federation 859 45 162

10 Mexico 471 0 88

11 UK 412 14 68

12 France 390 8 38

13 Brazil 315 0 103

14 Ukraine 243 0 83

15 New Zealand 140 11 18

Nanotechnology patent applications (1991-2008)

0

1,000

2,000

3,000

4,000

5,000

6,000

19911992199319941995199619971998199920002001

2002

2003200420052006

2007

2008

Year

Number of Patent Applications

US

PRC

Japan

South Korea

Fig. 3 The numbers of nanotechnology patent applications

from all countries in the patent offices of the US, PRC, Japan,

and South Korea using ‘‘title–abstract’’ search, from 1991 to

2008

J Nanopart Res

123
2004 to 2007 with 2006 as the peak (343 applications);

however, the number dropped dramatically in 2008 to

only three nanotechnology patent applications probably due to a delay in collecting the 2008 Taiwan patent

data by the esp@cenet ‘‘worldwide’’ database. In all

following analyses, we used 2007 data for Taiwan’s

patent office instead of 2008.

Most patent offices generally publish the country of

origin of the patent publications, with the exceptions

of Japan, Australia, and New Zealand. Table 3 lists the

top five countries where patent applications were filled

from 1991 to 2008. For several of the other patent

offices, a small portion of their patent applications

may have incomplete applicant country information.

In these cases, we manually verified the information.

For each application having the applicant same as the

inventor(s), we then used the country of the first

inventor as its applicant country. As a comparison, we

also list the numbers of nanotechnology patent applications published in 2000 (the year before the

establishment of the US National Nanotechnology

Initiative; Roco et al. 2000) and 2008 (the most recent

year with data available for the whole year).

The USA was the most active internationally with

the largest numbers of nanotechnology patent applicants published in other patent offices. It ranked first in

three out of the 12 patent offices, including its own

patent office, Canada’s, and Mexico’s patent offices; it

ranked second in the patent offices of six other

countries; and third in the remaining three patent

offices. Japan, Germany, South Korea, and France are

the most active internationally after the USA.

These results on country ranking generally are

consistent with those reported in the previous study on

granted patents at USPTO using ‘‘title–claims’’ search

(Li et al. 2007), in which study the top five applicant

countries of USPTO nanotechnology-granted patents

published from 1976 to 2004 were the US (3,450

patents), Japan (517 patents), Germany (204 patents),

France (156 patents), and South Korea (131 patents),

with Taiwan being the seventh. In this study, the top

five applicant countries identified were the US, Japan,

South Korea, Germany, and Taiwan. However, the

numbers of nanotechnology patent documents

reported in this study are different from those reported

by Li et al. (2007) due to three reasons. First, instead of

using the granted patents as used by Li et al. (2007), we

used the published patent applications as the data

source in this study, because the esp@cenet ‘‘worldwide’’ database does not differentiate granted patents

from published patent applications. Second, in this

study involving 15 repositories we could not use the

more complete ‘‘title/abstract/claims’’ used in previous study only for the USPTO. Third, our results are

based on the data published from 1991 to 2008 while

the numbers reported by Li et al. (2007) are based on

the data published from 1976 to 2004. Many patent

offices have published a large number of nanotechnology patents in recent years.

Table 3 shows that all the patent offices except

those of Canada and Mexico had the largest numbers

of nanotechnology patent applications published by

applicants from their own countries. This indicates a

‘‘home advantage’’ effect. As defined in previous

Nanotechnology patent applications (1991-2008)

0

50

100

150

200

250

300

350

400

19911992

199319941995

19961997

19981999

2000

2001200220032004

2005

20062007

2008

Year

Number of Patent Applications

Canada

Taiwan 

Australia

Germany

Russian

Federation

Mexico

United Kingdom

France 

Brazil

Ukraine 

New Zealand 

Fig. 4 The numbers of

nanotechnology patent

applications from all the

countries in the remaining

11 patent offices using

‘‘title–abstract’’ search from

1991 to 2008

J Nanopart Res

123
Table 3 Top five applicant countries in 12 countries/regions’ patent offices based on the number of nanotechnology patent applications

from 1991 to 2008

No. Patent office/repository

(no. of applications

from all countries)

Rank Applicant

country

Number of nanotechnology

patent applications

(1991–2008)

2000 2008

1 USA (19,665) 1 USA 12,606 285 2,288

2 Japan 1,866 42 308

3 South Korea 1,272 6 343

4 Germany 1,048 23 168

5 Taiwan 839 7 175

2 PRC (18,438) 1 PRC 16,348 85 4,409

2 USA 805 3 260

3 South Korea 327 5 80

4 Japan 301 2 64

5 Germany 145 3 43

3 South Korea (5,963) 1 South Korea 4,087 41 967

2 USA 461 15 151

3 PRC 145 1 53

4 Japan 138 4 39

5 Germany 119 0 42

4 Canada (1,539) 1 USA 825 18 156

2 Canada 192 4 28

3 Germany 124 7 18

4 France 57 6 7

5 Japan 53 2 5

5 Taiwan (1,363)a 1 Taiwan 906 3 165

2 USA 224 17 26

3 Japan 113 3 17

4 Germany 35 3 6

5 South Korea 32 2 10

6 Germany (1,312) 1 Germany 1,182 56 124

2 Taiwan 21 1 1

3 USA 20 1 3

4 South Korea 16 2 2

5 Japan 15 0 1

7 Russian Federation (859) 1 Russian Federation 711 41 147

2 USA 37 1 3

3 Japan 17 0 3

3 Germany 17 1 1

5 France 16 0 2

8 Mexico (471) 1 USA 277 0 53

2 Germany 30 0 5

3 Mexico 28 0 4

4 France 26 0 3

5 Switzerland 20 0 2

J Nanopart Res

123
studies, the ‘‘home advantage’’ effect is the tendency

of domestic applicants to file more patents with their

home country patent office than foreign applicants

(European Commission 1997; Ganguli 1998; Criscuolo 2005).

By comparing the numbers of nanotechnology

patent applications published in 2000 and 2008, the

tremendous increase in nanotechnology patent applications from each top applicant country can be easily

perceived. Especially notable are the increases

recorded by Mexico, Brazil, and Ukraine.

Top applicant institutions

Table 4 lists the leading five applicant institutions per

repository that includes large companies, universities,

and research centers. In each of the patent offices of

the PRC, South Korea, Germany, Russian Federation,

France, and Ukraine, all of the top five applicant

institutions were from the home country. In contrast,

all the top five applicant institutions in Australia’s

patent office came from the USA. Four out of the top

five application institutions in both Canada’s and

Mexico’s patent offices were from the USA. In

addition, none of the top five applicant institutions in

New Zealand’s patent office was from its home

country. Some internationally active applicant institutions that ranked among the top five in different

countries’/regions’ patent offices included IBM (from

the US), the University of California (from the USA),

Samsung Electronics Co. Ltd. (South Korea), Hon

Hai Prec Ind Co. Ltd. (Taiwan), Industrial Technology Research Institute (Ind Tech Res Inst; Taiwan),

Hyperion Catalysis International Inc. (USA), and

General Electric (USA).

In the USA’s patent office, IBM ranked first,

followed by the University of California and Samsung Electronic Co. In Japan’s patent office, the

National Institute for Materials Science (Nat Inst for

Materials Science) ranked first followed by the National

Institute of Advanced Industrial Science and Technology (Nat Inst of Adv Ind & Technol) and Matsushita

Table 3 continued

No. Patent office/repository

(no. of applications

from all countries)

Rank Applicant

country

Number of nanotechnology

patent applications

(1991–2008)

2000 2008

9 UK (412) 1 UK 162 5 27

2 USA 109 8 15

3 Germany 25 0 7

4 Japan 20 0 3

5 South Korea 19 1 5

10 France (390) 1 France 358 6 37

2 Belgium 6 0 2

2 Japan 6 0 0

4 Taiwan 5 0 0

4 USA 5 2 0

11 Brazil (315) 1 Brazil 116 0 42

2 USA 99 0 32

3 Germany 25 0 8

4 Switzerland 21 0 4

5 France 15 0 5

12 Ukraine (243) 1 Ukraine 221 0 78

2 Switzerland 4 0 3

3 Japan 2 0 0

4 Switzerland 1 0 0

4 USA 1 0 0

a As noted previously, data from 2007 was used for Taiwan’s patent office, rather than 2008

J Nanopart Res

123
Table 4 Top five applicant institutions in the 15 patent offices based on the number of nanotechnology patent applications from

1991 to 2008

No. Patent office/

repository

Rank Applicant institution Country of

the institution

Number of

nanotechnology

patent applications

(1991–2008)

2000 2008

1 USA 1 IBM USA 277 11 54

2 Univ California USA 209 11 29

3 Samsung Electronics Co. Ltd. South Korea 172 0 69

4 Hon Hai Prec Ind Co. Ltd. Taiwan 157 0 54

5 Ind Tech Res Inst Taiwan 106 3 15

2 PRC 1 Chinese Academy of Sciencea PRC 1,155 14 312

2 Univ Zhejiang PRC 464 3 129

3 Univ Tsinghua PRC 461 2 91

4 Univ Shanghai Jiaotong PRC 409 3 75

5 Univ Fudan PRC 317 3 81

3 Japan 1 Nat Inst for Materials Science Japan 334 0 60

2 Nat Inst of Adv Ind & Technol Japan 322 0 69

3 Matsushita Electric Ind Co. Ltd. Japan 263 6 37

4 Fujitsu Ltd. Japan 247 13 48

5 Canon Kk. Japan 222 11 26

4 South Korea 1 Samsung Electronics Co. Ltd. South Korea 327 1 82

2 Korea Inst Science Technology South Korea 253 3 57

3 LG Electronics Inc. South Korea 153 2 26

4 Samsung Sdi Co. Ltd. South Korea 144 1 12

5 Seoul National University South Korea 120 0 46

5 Canada 1 Xerox Co. US 27 0 18

2 Nantero Inc. US 25 0 0

3 Nat Res Council Canada 23 1 1

4 Hyperion Catalysis International Inc. USA 21 0 3

5 Nanosys Inc. USA 18 0 0

6 Taiwanb 1 Ind Tech Res Inst Taiwan 201 0 23

2 Hon Hai Prec Ind Co. Ltd. Taiwan 78 0 51

3 Univ Nat Cheng Kung Taiwan 32 0 2

4 IBM USA 25 3 28

5 Univ Nat Chiao Tung Taiwan 17 0 3

7 Germany 1 Infineon Technologies AG Germany 55 0 0

2 Fraunhofer Ges Forschung Germany 44 4 4

3 Siemens AG Germany 36 2 10

4 Henkel Kgaa Germany 31 5 0

5 Hahn Meitner Inst Berlin Gmbh Germany 20 0 0

8 Australia 1 Univ California US 37 3 5

2 Univ Northwestern US 18 1 0

3 Hyperion Catalysis International Inc. US 16 3 4

4 Nanosphere Inc. US 15 0 1

5 Harvard College US 14 0 1

9 Russian Federation 1 G Obrazovatel Noe Uchrezhdenie Russian Fed. 45 0 22

2 Zao NT MDT Russian Fed. 11 4 1

3 Boreskova Inst Kataliza Sibir Russian Fed. 10 1 3

3 Inst Fiz Tverdogo Tela Ran Russian Fed. 10 0 6

3 Inst Ehlektrofiziki Ural Skogo Russian Fed. 10 6 0

J Nanopart Res

123
Electric Ind Co. Ltd. In PRC’s patent offices, all the

leading applicants are academic or academy research

institutions.

Compared with 2000, there is a general increase in

the number of nanotechnology patent applications

published by the top institutions in 2008. Among the

top five institutions, in each of the patent offices of

the USA, PRC, and Australia, the institution with the

largest numbers of nanotechnology patent applications from 1991 to 2008 also ranked first in 2000.

Top technology fields

We used the International Patent Classification (IPC)

class instead of the European Patent Classification

(EPC) class to indicate technology fields in Table 5

Table 4 continued

No. Patent office/

repository

Rank Applicant institution Country of

the institution

Number of

nanotechnology

patent applications

(1991–2008)

2000 2008

10 Mexico 1 Procter & Gamble USA 23 0 2

2 Elan Pharma International Ltd. Ireland 9 0 9

2 Hyperion Catalysis International Inc. USA 9 0 0

4 Kimberly Clark Co. USA 8 0 1

4 Rohm & Haas USA 8 0 0

11 UK 1 Toshiba Res Europ Ltd. UK 13 1 4

2 Hitachi Europ Ltd. UK 9 0 0

3 Gen Electric USA 8 1 0

4 Intel Co. USA 7 0 3

5 Waters Investments Ltd. USA 6 0 0

12 France 1 Centre Nat Rech Scient France 58 0 5

2 Commissariat Energie Atomique France 41 1 3

3 O’real France 27 0 0

4 Rhone Poulenc Chimie France 10 0 0

5 Arkema Sa France 8 0 0

13 Brazil 1 Unicamp Brazil 13 0 1

2 Comissao Nac de En Nuclear Brazil 8 0 1

3 Gen Electric US 6 0 2

4 Du Pont US 5 0 5

5 Gomes Uilame Umbelino Brazil 5 0 1

14 Ukraine 1 Kaplunenko Volodymyr Heorhiiov Ukraine 99 0 53

1 Kosinov Mykola Vasyliovych Ukraine 99 0 53

3 Shulzhenko Oleksandr Oleksandr Ukraine 6 0 0

4 Lytvynenko Yurii

Mykhailovych

Ukraine 5 0 0

5 Lviv Polytekhnika

Nat Universi

Ukraine 4 0 1

15 New Zealand 1 Eastman Kodak Co. US 4 0 0

2 Snow Brand Milk Prod Co. Ltd. Japan 3 1 0

3 Smithkline Beecham Co. USA 2 0 0

3 Technologies Avancees & Membra France 2 0 0

3 Univ Johns Hopkins USA 2 0 0

a In our data collection, Chinese Academy of Sciences had variations of its name in English and it also has several affiliated organizations. We

manually checked and came up with 27 different institution names which are all essentially Chinese Academy of Sciences. The number reported in the

table is the sum of all the nanotechnology patent applications published by these 27 institutions

b As noted previously, data from 2007 was used for Taiwan’s patent office, rather than 2008

J Nanopart Res

123
Table 5 Top five technology fields in the 15 patent offices based on the number of nanotechnology patent applications from 1991 to

2008

No Patent office/

repository

Rank IPC class Class name Number of

nanotechnology patent

applications

(1991–2008)

2000 2008

1 USA 1 H01L Semiconductor devices; electric solid state devices

not otherwise provided for

4,203 76 743

2 A61K Preparations for medical, dental, or toilet purposes 1,974 51 367

3 G01N Investigating or analyzing materials by determining

their chemical or physical properties

1,754 36 230

4 C01B Non-metallic elements; compounds thereof 1,453 23 187

5 B32B Layered products, i.e., products built-up of strata of

flat or non-flat, e.g., cellular or honeycomb

1,400 15 444

2 PRC 1 A61K Preparations for medical, dental, or toilet purposes 1,549 9 370

2 C01B Non-metallic elements; compounds thereof 1,501 14 392

3 B01J Chemical or physical processes, e.g., catalysis,

colloid chemistry; their relevant apparatus

1,311 11 388

4 C08L Compositions of macromolecular compounds 1,247 7 349

5 H01L Semiconductor devices; electric solid state devices

not otherwise provided for

1,095 4 350

3 Japan 1 H01L Semiconductor devices; electric solid state devices

not otherwise provided for

2,324 81 367

2 C01B Non-metallic elements; compounds thereof 1,994 55 292

3 B82B Nano-structures manufacture or treatment thereof 1,599 35 229

4 G01N Investigating or analyzing materials by determining

their chemical or physical properties

1,123 47 89

5 H01J Electric discharge tubes or discharge lamps 1,031 58 82

4 South Korea 1 B82B Nano-structures manufacture or treatment thereof 1,280 5 417

2 H01L Semiconductor devices; electric solid state devices

not otherwise provided for

1,094 29 238

3 C01B Non-metallic elements; compounds thereof 409 5 103

4 C08K Use of inorganic or non-macromolecular organic

substances as compounding ingredients

374 0 88

5 H01J Electric discharge tubes or discharge lamps 361 7 30

5 Canada 1 A61K Preparations for medical, dental, or toilet purposes 328 8 47

2 G01N Investigating or analyzing materials by determining

their chemical or physical properties

169 7 9

3 B01J Chemical or physical processes, e.g., catalysis,

colloid chemistry; their relevant apparatus

148 10 8

4 C01B Non-metallic elements; compounds thereof 144 2 23

5 H01L Semiconductor devices; electric solid state devices

not otherwise provided for

123 4 22

6 Taiwana 1 H01L Semiconductor devices; electric solid state devices

not otherwise provided for

367 11 47

2 C01B Non-metallic elements; compounds thereof 114 1 14

3 H01J Electric discharge tubes or discharge lamps 112 1 9

4 C23C Coating metallic material coating material with

metallic material surface treatment of metallic

material by diffusion into the surface, by

chemical conversion or substitution coating by

vacuum evaporation, by sputtering, by ion

implantation or by chemical vapor deposition, in

general

78 2 13

5 G01N Investigating or analyzing materials by determining

their chemical or physical properties

71 0 15

J Nanopart Res

123
Table 5 continued

No Patent office/

repository

Rank IPC class Class name Number of

nanotechnology patent

applications

(1991–2008)

2000 2008

7 Australia 1 A61K Preparations for medical, dental, or toilet purposes 295 22 19

2 C01B Non-metallic elements; compounds thereof 212 12 7

3 H01L Semiconductor devices; electric solid state devices

not otherwise provided for

209 9 11

4 B01J Chemical or physical processes, e.g., catalysis,

colloid chemistry; their relevant apparatus

177 10 12

5 G01N Investigating or analyzing materials by determining

their chemical or physical properties

163 15 4

8 Germany 1 H01L Semiconductor devices; electric solid state devices

not otherwise provided for

165 7 17

2 B01J Chemical or physical processes, e.g., catalysis,

colloid chemistry; their relevant apparatus

135 13 10

3 B82B Nano-structures manufacture or treatment thereof 121 3 16

4 G01N Investigating or analyzing materials by determining

their chemical or physical properties

111 3 13

5 A61K Preparations for medical, dental, or toilet purposes 103 6 8

9 Russian

Federation

1 B82B Nano-structures manufacture or treatment thereof 118 2 55

2 H01L Semiconductor devices; electric solid state devices

not otherwise provided for

88 4 13

3 C01B Non-metallic elements; compounds thereof 75 2 16

4 B01J Chemical or physical processes, e.g., catalysis,

colloid chemistry; their relevant apparatus

69 6 15

5 A61K Preparations for medical, dental, or toilet purposes 58 1 12

10 UK 1 H01L Semiconductor devices; electric solid state devices

not otherwise provided for

83 2 16

2 G01N Investigating or analyzing materials by determining

their chemical or physical properties

58 2 15

3 B01D Separation 30 2 2

4 A61K Preparations for medical, dental, or toilet purposes 29 0 7

5 C01B Non-metallic elements; compounds thereof 28 0 2

11 Mexico 1 A61K Preparations for medical, dental, or toilet purposes 109 0 26

2 B01J Chemical or physical processes, e.g., catalysis,

colloid chemistry; their relevant apparatus

60 0 0

3 C08K Use of inorganic or non-macromolecular organic

substances as compounding ingredients

58 0 8

4 C08L Compositions of macromolecular compounds 52 0 3

5 C09D Coating compositions, e.g. paints, varnishes,

lacquers; filling-pastes; chemical paint or ink

removers; inks; correcting fluids; wood stains;

pastes or solids for coloring or printing; use of

materials therefore

45 0 8

12 France 1 A61K Preparations for medical, dental, or toilet purposes 69 0 2

2 H01L Semiconductor devices; electric solid state devices

not otherwise provided for

61 0 6

3 B82B Nano-structures manufacture or treatment thereof 55 0 7

4 C01B Non-metallic elements; compounds thereof 47 0 7

5 A61Q Use of cosmetics or similar toilet preparations 45 0 2

J Nanopart Res

123
because the EPC class information is incomplete in

some patent offices (repositories). Among the top five

technology fields in the 15 patent offices, there were

19 unique IPC classes, 10 of which ranked among the

top five in more than one patent office:

– ‘‘Semiconductor devices; electric solid state

devices not otherwise provided for’’ (H01L)

ranked among the top five in 11 patent offices

(except in those of Mexico, Brazil, the Ukraine,

and New Zealand)

– ‘‘Preparations for medical, dental, or toilet purposes’’ (A61K) ranked among the top five in 11

patent offices (except in those of Japan, South

Korea, Taiwan, and the Ukraine)

– ‘‘Non-metallic elements; compounds thereof’’

(C01B) ranked among the top five in 11 patent

offices (except in those of Germany, Mexico,

Brazil, and New Zealand)

– ‘‘Chemical or physical processes, e.g., catalysis,

colloid chemistry; their relevant apparatus’’

(B01J) also ranked among the top five in nine

patent offices

– ‘‘Investigating or analyzing materials by determining their chemical or physical properties’’ (G01N)

ranked among the top five in seven patent offices

– ‘‘Nano-structures manufacture or treatment

thereof’’ (B82B) ranked among the top five in

six patent offices.

In the USPTO, ‘‘Semiconductor devices; electric

solid state devices not otherwise provided for’’ (H01L)

ranked first, followed by ‘‘Preparations for medical,

dental, or toilet purposes’’ (A61K). Such rankings are

consistent with the results reported in our previous

study for granted patents. In addition, ‘‘Investigating or

analyzing materials by determining their chemical or

physical properties’’ (G01N) and ‘‘Layered products,

i.e., products built-up of strata of flat or non-flat, e.g.,

cellular or honeycomb’’ (B32B), which ranked third

and fifth, respectively, in this study, ranked fifth and

fourth, respectively, in the previous study (Li et al.

2007). However, ‘‘Non-metallic elements; compounds

thereof’’ (C01B), which was also among the top five,

did not appear among the top 10 technology fields as

reported by Li et al. (2007).

Table 5 continued

No Patent office/

repository

Rank IPC class Class name Number of

nanotechnology patent

applications

(1991–2008)

2000 2008

13 Brazil 1 A61K Preparations for medical, dental, or toilet purposes 65 0 21

2 C08K Use of inorganic or non-macromolecular organic

substances as compounding ingredients

30 0 7

3 C08L Compositions of macromolecular compounds 28 0 6

4 B01J Chemical or physical processes, e.g., catalysis,

colloid chemistry; their relevant apparatus

28 0 8

5 B82B Nano-structures manufacture or treatment thereof 24 0 12

14 Ukraine 1 B01J Chemical or physical processes, e.g., catalysis,

colloid chemistry; their relevant apparatus

52 0 25

2 C01B Non-metallic elements; compounds thereof 24 0 3

3 B22F Working metallic powder; manufacture of articles

from metallic powder; making metallic powder

21 0 4

4 C12N Micro-organisms or enzymes; compositions thereof 19 0 16

5 C02F Treatment of water, waste water, sewage, or sludge 18 0 4

15 New Zealand 1 A61K Preparations for medical, dental, or toilet purposes 62 4 8

2 A61P Therapeutic activity of chemical compounds or

medicinal preparations

28 1 3

3 B01J Chemical or physical processes, e.g., catalysis,

colloid chemistry; their relevant apparatus

20 2 4

4 B01D Separation 18 1 3

5 C07K Peptides 17 0 3

a As noted previously, data from 2007 was used for Taiwan’s patent office, rather than 2008

J Nanopart Res

123
In Japan’s patent office, ‘‘Semiconductor devices;

electric solid state devices not otherwise provided

for’’ (H01L) ranked first, followed by ‘‘Non-metallic

elements; compounds thereof’’ (C01B), ‘‘Nano-structures manufacture or treatment thereof’’ (B82B),

‘‘Investigating or analyzing materials by determining

their chemical or physical properties’’ (G01N), and

‘‘Electric discharge tubes or discharge lamps’’

(H01J). All these technology fields ranked among

the top 10 in the previous study (Li et al. 2007).

Except ‘‘Nano-structures manufacture or treatment

thereof’’ (B82B), which ranked eighth in Li et al.

(2007), they all ranked among the top five as well.

Compared to 2000, there were many more nanotechnology patent applications in the top five technology fields in 2008 for different patent offices,

including the patent offices of the USA, PRC, Japan,

South Korea, Canada, Germany, Russian Federation,

the UK, Mexico, France, Brazil, the Ukraine, and

New Zealand. Since the patent offices of Mexico,

Brazil, and Ukraine did not have nanotechnology

patent applications in 2000, there were no applications from their top five technology fields in 2000. In

addition, none of the eight applications in France’s

patent office in 2000 belonged to its top five

technology fields. In 2008, almost all the top five

technology fields in each of the 15 patent offices had

nanotechnology patent applications.

For the patent offices of the USA, Japan, Taiwan,

Australia, and New Zealand, the technology field that

ranked the first in each of them based on data from 1991

to 2008 also had the largest number of nanotechnology

patent applications in 2000. In 2008, there were 13

patent offices (excepting the patent offices of PRC and

France) for which the technology field which ranked

first based on data from 1991 to 2008, also had the

largest number of nanotechnology patent applications

in 2008 (Taiwan in 2007).

Topic analysis

Content maps were used to visualize the major

technology topics in different patent offices (repositories). Since the patent offices of the USA and PRC

had many more nanotechnology patent applications

than other countries, we created content maps for

both of them. In order to get a better understanding of

the topic evolution for all the 15 patent offices, we

also created content maps using the data from all the

15 patent offices for years 2000 and 2008.

We used the multi-level self-organization map

algorithm (Chen et al. 1996; Ong et al. 2005)

developed by the Artificial Intelligence Lab at the

University of Arizona. A content map has two

components: a folder tree, and a hierarchical map.

Each node in the folder tree, corresponding to a region

in the hierarchical map, is a topic (keyword) identified

from the document. Conceptually closer technology

topics are positioned closer geographically. The

numbers of documents assigned to the different levels

of topics are presented after the topic labels. The size

of each topic region also generally corresponds to the

number of documents assigned to the topic. For each

topic region, a growth rate is computed as the ratio

between the number of documents in the current time

period and that of the previous time period. A baseline

growth rate is computed as the ratio between the total

number of documents in the current time period and

that of the previous time period. A topic region with a

growth rate similar to the base growth rate is assigned

a green color. A topic region with a higher or lower

growth rate is assigned a warmer or colder color,

respectively. If the topic is brand new, a red color is

assigned to the region.

Figures 5, 6, and 7 show the content maps for the

patent office of the USA in 2008 for USPTO, PRC,

and for all the 15 patent offices, respectively. The

data in 2008 for USPTO and all the 15 countries are

compared to data in 2000. For the patent office of the

PRC, the 2008 data cannot be statistically well

compared to data in 2000, because the number of

nanotechnology patent applications in 2000 is too

limited to generate a content map at that date.

Compared with 2000, the nanotechnology patent

applications published in the USPTO in 2008 (Fig. 5)

have a baseline growth rate of 16.14 times, indicating a

significant increase in nanotechnology research. Topics that appear in both years are: ‘‘Aqueous solutions,’’

‘‘Dielectric layers,’’ and ‘‘Metal oxides,’’ each of which

had many more applications in 2008 than in 2000.

Topics which appeared in 2000 only included:

– Nanomaterial-related topics, such as ‘‘Carbon

atoms,’’ ‘‘Carbon nanotubes,’’ and ‘‘Memory cells’’

– Properties of nanomaterials, such as ‘‘Average

molecular weight,’’ ‘‘Low dielectric,’’ ‘‘Molecular

weights,’’ and ‘‘Surface roughness’’

J Nanopart Res

123
– Nano-device related topics, such as ‘‘Alkali

metals,’’ ‘‘Laser beams,’’ ‘‘Light source,’’ ‘‘Magnetic recording medium,’’ ‘‘Silicon substrates,’’

‘‘Substrate surfaces’’

– Measurement- and method-related topics, such as

‘‘Nanometers at reaction conditions,’’ ‘‘Surface

roughness,’’ and ‘‘Ultraviolet radiation.’’

The newly emerging topics of 2008 included:

– Nanomaterial-related topics, such as ‘‘Composite

materials,’’ ‘‘Metal nanoparticles,’’ ‘‘Quantum dots,’’

‘‘Single walled carbon nanotubes,’’ ‘‘Solar cells,’’

and ‘‘Thin films’’

– Properties of nanomaterials, such as ‘‘Average

particle sizes,’’ ‘‘Effective average particle size,’’

and ‘‘Electrical conductivities’’

– Nano-device related topics, such as ‘‘Electric

fields,’’ ‘‘Electronic devices,’’ ‘‘Field emission

devices,’’ ‘‘Insulating layer,’’ ‘‘Memory devices,’’

‘‘Semiconductor substrate,’’ ‘‘Therapeutic agents’’

– Measurement- and method-related topics, such as

‘‘Atomic force microscope,’’ ‘‘Chemical vapor

deposition,’’ ‘‘Electromagnetic radiation,’’ and

‘‘Fabrication method.’’

As shown in Fig. 6, the largest topic in the patent

office of the PRC in 2008 was ‘‘human bodies’’ with

295 nanotechnology patent applications. Topics

related to nanomaterials included ‘‘Carbon nanotube,’’

‘‘Composite materials,’’ ‘‘Nanometer materials,’’

‘‘Quantum dots,’’ and ‘‘Thin films.’’ Topics related to

properties of nanomaterials were ‘‘Good stability,’’

‘‘Grain diameter,’’ ‘‘High activity,’’ ‘‘High sensitivity,’’ ‘‘Molar ratio,’’ ‘‘pH values,’’ ‘‘Service life,’’ and

‘‘Weight percentages.’’ Topics related to nano-device

included ‘‘Deionized water,’’ ‘‘Organic solvents,’’ and

‘‘Stainless steels.’’ Topics related to measurements and

methods included ‘‘Aqueous solutions,’’ ‘‘Convenient

operation,’’ ‘‘Production method,’’ and ‘‘Water

solution.’’

Fig. 5 The content map for patent applications at the USPTO in 2008 (the color means the rate of increase as compared to 2000; the

‘‘new region’’ in red is 92%)

J Nanopart Res

123
Compared with 2000 the nanotechnology patent

applications published in all, the 15 patent offices in

2008 (Fig. 7) had a baseline growth rate of 12.57,

indicating a significant increase in nanotechnology

research. Six main topics that appeared in both years

included:

– ‘‘Average particle size’’

– ‘‘Aqueous solutions’’

– ‘‘Metal oxides’’

– ‘‘Manufacturing method’’

– ‘‘Thin films’’

– ‘‘Functional groups’’

Each of these topics had significantly more

applications in 2008 than in 2000.

Older main topics that appeared in 2000 only

included:

– Nanomaterial-related topics, such as ‘‘Carbon nanotube,’’ ‘‘Composite materials,’’ ‘‘Organic polymer,’’

‘‘Quantum dot,’’ and ‘‘Such films’’

– Properties of nanomaterials, such as ‘‘Average

pore diameter,’’ ‘‘Average size,’’ ‘‘High densities,’’ ‘‘Molecular weights,’’ ‘‘Surface roughness,’’ ‘‘Weight ratio,’’ etc.

– Nano-device related topics, such as ‘‘Electric

fields,’’ ‘‘Electron beams,’’ ‘‘Laser beams,’’ ‘‘Light

source,’’ ‘‘Magnetic cores,’’ ‘‘Semiconductor substrates,’’ and ‘‘Transition metals’’

– Measurement- and method-related topics, such as

‘‘Atomic force microscope,’’ ‘‘Electromagnetic

radiation,’’ and ‘‘Ultraviolet radiation’’

The newly emerging topics for 2008 included:

– Nanomaterial-related topics, such as ‘‘Composite

materials,’’ ‘‘Metal nanoparticles,’’ and ‘‘Quantum dots’’

– Properties of nanomaterials, such as ‘‘pH values,’’

‘‘High purities,’’ and ‘‘Particle diameters’’

– Nano-device related topics, such as ‘‘Organic

solvents,’’ ‘‘Semiconductor Devices,’’ ‘‘Deionized water,’’ and ‘‘Gate electrodes’’

There were no new topics related to certain

measurements or methods.

Patent family analysis

The patent office of each country or region has the

jurisdiction to grant a patent for its own geographic

Fig. 6 The content map for

the patent office of the PRC

in 2008

J Nanopart Res

123
area only. In order to achieve broader coverage of the

exclusive rights for an invention, some patent applications are filed in multiple countries’/regions’ patent

offices, and, thus, become a patent family. All the

patent applications (or granted patents) in a given

patent family are equivalents and considered to be

one invention.

Patent family analysis within each patent office

Table 6 lists the numbers of nanotechnology patent

applications published in single patent office, two or

more patent offices, and three or more patent offices.

For example, 2,939 patent applications that were

published in the US patent office had been also

published in at least one other patent office. Among

those patent applications, 741 had been published in

three or more countries’/regions’ patent offices. The

patent offices of Japan, the PRC, and South Korea

also had relatively larger numbers of nanotechnology

patent applications published in multiple patent

offices.

For each patent office, we also identified other

patent offices with which it shared the greatest

numbers of nanotechnology patent applications for

the interval between 1991 and 2008. For example,

– The top five patent offices sharing nanotechnology patent applications with the USPTO were

Japan (1,258), PRC (725); South Korea (636),

Taiwan (353), and Canada (350). Our analysis

shows that all other patent offices (except for

Brazil’s patent offices) shared the largest numbers

of nanotechnology patent applications with the

USPTO.

– The top five patent offices sharing nanotechnology patent applications with the PRC repository

were those of the USA (725), South Korea (624),

Japan (416), Taiwan (68), and Canada (40).

– The top five patent offices sharing nanotechnology patent applications with the JPO were those

of the USA (1258), South Korea (450), PRC

(416), Taiwan (107), and Canada (106).

Patent family analysis across patent offices

The network in Fig. 8 shows patent families across

patent offices. In the network, nodes represent different

countries’/regions’ patent offices. The bigger the node,

the higher the number of nanotechnology patent

applications it shares with other countries’/regions’

patent offices. The number of nanotechnology patent

applications each patent office shared with others is

Table 6 Numbers of nanotechnology patent applications published in single patent office, two or more patent offices, and three or

more patent offices (1991–2008)

No. Patent office

(repository)

No. of patent

applications

published in total

No. of patent

applications published

in a single patent office

No. of patent applications

published in C2 patent

offices

No. of patent applications

published in C3 patent

offices

1 USA 19,665 16,726 2,939 741

2 PRC 18,438 17,079 1,359 490

3 Japan 10,763 9,084 1,679 614

4 South Korea 5,963 4,731 1,232 491

5 Canada 1,539 988 551 160

6 Taiwan 1,363 900 463 123

7 Australia 1,312 926 386 91

8 Germany 1,296 1,229 67 21

9 Russian Federation 859 785 74 31

10 Mexico 471 228 243 96

11 UK 412 291 121 32

12 France 390 339 51 17

13 Brazil 315 167 148 70

14 Ukraine 243 231 12 6

15 New Zealand 140 68 72 38

J Nanopart Res

123
presented in parentheses after the node label. The link

between two patent offices means that they have

published nanotechnology patent applications in the

same patent families. The thicker the link, the greater the

number of nanotechnology patent applications the two

patent offices shared. The number beside the link

indicates how many nanotechnology patent applications

the two patent offices shared. The network was drawn

using open source software, NetDraw (available at:

http://www.analytictech.com/Netdraw/netdraw.htm/).

Each of the top 15 patent offices shared nanotechnology patent applications with other patent offices.

The USPTO shared the largest number of nanotechnology patent applications with others (2,939),

followed by the patent offices of Japan, PRC, and

South Korea (1,679; 1,359; and 1,232 nanotechnology patent applications, respectively). The thickest

link in the network shows that the patent offices of

the US and Japan shared the largest number of

nanotechnology patent applications (i.e., 1,258

applications).

We have identified 12 patent families that had

equivalent nanotechnology patent applications published in at least five patent offices. The titles of the

equivalent patents may or may not be the same.

Conclusions

The nanotechnology patent applications published in

different countries’/regions’ patent offices have been

evaluated by using the esp@cenet ‘‘worldwide’’

database. Key findings from the longitudinal analysis

of nanotechnology patent applications between 1991

and 2008 are:

• The worldwide growth rate of the number of

nanotechnology patent applications between

2000 and 2008 is about 34.5% (Fig. 1). This

rate is larger than the corresponding rate of

increase for International Citation Index articles

of about 25%. The baseline growth rates of the

number of patent applications for continuing

Fig. 7 The content map for

all 15 patent offices in 2008

(the color means the rate of

increase as compared to

2000; the ‘‘new region’’ in

red is 68%)

J Nanopart Res

123
topics are 16.14 and 12.57 times in the interval

from 1991 to 2008 for the USPTO and the top

15 nanotechnology patent repositories, respectively. The new nanotechnology topics in 2008

as compared with 2000 represent 92% in the

USA (Fig. 5) and 68% for top 15 repositories

(Fig. 7). The baseline growth rate is significant

in the PRC patent office, but the data available

in 2000 are too limited to generate a content

map in that year for comparison with 2008. The

largest number of nanotechnology patent applications, as well as of the patent application

families, are at the patent offices of the USA,

PRC, Japan, and South Korea.

• A higher number of nanotechnology patent

applications are published by applicants from

their own countries/regions, indicating significant

‘‘home advantage’’ effects. The USA, Japan,

Germany, South Korea, and France were the

largest contributors in patent offices other than its

repository. The top 15 patent offices except for

Brazil’s patent office shared the largest numbers

of nanotechnology patent applications with the

USPTO. Japan is the USPTO’s largest partner cosharing 1,258 nanotechnology patent applications.

• Applicant institutions with large international

activity are illustrated by IBM (from the USA),

the University of California (from the USA),

Samsung Electronics Co. Ltd. (from South

Korea), Hon Hai Prec Ind Co. Ltd. (from Taiwan),

and Industrial Technology Research Institute (Ind

Tech Res Inst; from Taiwan), Hyperion Catalysis

International Inc. (from the USA), and General

Electric (Gen Electric, from the USA).

• The ranking of the most productive institutions

and the categories of the lead technology fields in

patent repositories have had relatively small

changes over time, and few institutions or categories of technology fields were able to break into

the top ranks. However, specific topics within

various technology field categories changed

rapidly after 2000. Topics that increased in

2008 in most of the 15 patent offices included:

‘‘Composite materials,’’ ‘‘Deionized water,’’

‘‘Gate electrodes,’’ ‘‘High purities,’’ ‘‘Metal nanoparticles,’’ ‘‘Organic solvents,’’ ‘‘Particle diameters,’’

‘‘PH values,’’ ‘‘Quantum dots,’’ and ‘‘Semiconductor

Devices.’’

• Several top technology fields (represented by IPC

class) were shared by multiple repositories.

Fig. 8 Patent families

across leading 15 patent

offices for nanotechnology

applications from 1991 to

2008

J Nanopart Res

123
‘‘Semiconductor devices; electric solid state

devices not otherwise provided for’’ (H01L) was

among the top five technology fields in 11 out of

the 15 patent offices. The following fields ranked

among the top five in multiple repositories:

‘‘Preparations for medical, dental, or toilet purposes’’ (A61K), ‘‘Non-metallic elements; compounds thereof’’ (C01B), ‘‘Chemical or physical

processes, e.g., catalysis, colloid chemistry; their

relevant apparatus’’ (B01J), ‘‘Investigating or analyzing materials by determining their chemical or

physical properties’’ (G01N), and ‘‘Nano-structures

manufacture or treatment thereof’’ (B82B).

Acknowledgments This research was supported by the

following awards: National Science Foundation: ‘‘Intelligent

Patent Analysis for Nanoscale Science and Engineering,’’ IIS0311652; ‘‘Mapping Nanotechnology Development,’’ DMI0533749; and ‘‘Worldwide Nanotechnology Development: A

Comparative Study of Global Patents’’ CMMI-0654232. The last

co-author was supported by the Directorate for Engineering,

NSF. We would like to thank esp@cenet for making the

‘‘worldwide’’ database available for research.

References

Albert R, Barabasi AL (2002) Statistical mechanics of complex

networks. Rev Mod Phys 74:47–97

Andersen PH, Drejer I, Waldstrøm C (2006) In the eye of the

storm—knowledge appropriation and the globalization of

regional competencies. In: The proceedings of the annual

meeting of the Academy of Management

Chemical Abstracts Service (April 24, 2008) Patent terminology.

Available http://www.stn-international.de/training_center/

patents/pat_term.pdf

Chen H, Schuffels C, Orwig R (1996) Internet categorization

and search: a machine learning approach. J Vis Commun

Image Represent 7(1):88–102

Criscuolo P (2005) The ‘home advantage’ effect and patent

families. A comparison of OECD triadic patents, the USPTO

and the EPO. Scientometrics 66(1):23–41

EPO (2008) Global patent data coverage. Available http://

documents.epo.org/projects/babylon/eponet.nsf/0/2464E1

CD907399E0C12572D50031B5DD/$File/global_patent_

data_coverage.pdf

Espacenet Website. Also published as documents. Retrieved

April 24, 2009, from http://ep.espacenet.com/help?topic=

publishedas&&method=handleHelpTopic&locale=

en_ep

Espacenet Website. Corresponding documents. Retrieved April

24, 2009, from http://ep.espacenet.com/help?topic=cor

responding&method=handleHelpTopic&locale=en_ep

Espacenet Website. Coverage of the worldwide database.

Retrieved April 24, 2009, from http://ep.espacenet.com/

help?topic=coverageww

Espacenet Website. esp@cenet databases. Retrieved April 24,

2009, from http://ep.espacenet.com/help?topic=coveragesqh

&locale=en_EP&method=handleHelpTopic

Espacenet Website. Patent families. Retrieved April 24, 2009,

from http://ep.espacenet.com/help?locale=en_EP&method=

handleHelpTopic&topic=patentfamily

Espacenet Website. What is a cited document? Retrieved April

24, 2009, from http://v3.espacenet.com/answer?AID=3&

AACT=textdoc

European Commission (1997) Second European report on S&T

indicators. European Commission, Brussels

Ganguli P (1998) Intellectual property rights in transition.

World Pat Inf 20(3–4):171–180

Garfield E (1955) Citation indexes for science: a new dimension in

documentation through association of ideas. Science 122:

108–111

Hingley P, Park W (2003) Patent family data and statistics at

the European Patent Office. WIPO-OED workshop on

statistics in the patent field, Geneva

Hu D, Chen H, Huang Z, Roco MC (2007) Longitudinal study

on patent citations to academic research articles in nanotechnology (1976–2004). J Nanopart Res 9(4):529–542

Huang Z, Chen H, Yip A, Ng G, Guo F, Chen Z-K, Roco MC

(2003) Longitudinal patent analysis for nanoscale science

and engineering: country, institution and technology field.

J Nanopart Res 5:333–363

Huang Z, Chen H, Li X, Roco MC (2006) Connecting NSF

funding to patent innovation in nanotechnology (2001–

2004). J Nanopart Res 8(6):859–879

Li X, Lin Y, Chen H, Roco MC (2007) Worldwide nanotechnology development: a comparative study of USPTO, EPO, and

JPO patents (1976–2004). J Nanopart Res 9(6):977–1002

Narin F (1998) Patents and publicly funded research: assessing

the value of research in the chemical sciences. National

Academy Press, Washington, pp 59–72

Oldham P, Cutter AM (2006) Mapping global status and trends

in patent activity for biological and genetic material.

Genomics Soc Policy 2(2):62–91

Ong T-H, Chen H, Sun W-K, Zhu B (2005) News map: a

knowledge map for online news. Decis Support Syst 39(4):

583–597

Oppenheim C (2000) Do patent citations count? The Web of

Knowledge (Information Today Inc.), Medford

Roco MC (2005) International perspective on government nanotechnology funding in 2005. J Nanopart Res 7(6):707–712

Roco MC, Williams RS, Alivisatos P (2000) Nanotechnology

research directions. Springer, Dordrecht

Seymour EH, Borges FC, Fernandes R (2007) Indicators of

European public research in hydrogen and fuel cells—an

input–output analysis. Int J Hydrogen Energy 32:3212–3222

Tolle K, Chen H (2000) Comparing noun phrasing techniques

for use with medical digital library tools. J Am Soc Inf Sci

51(4):352–370

J Nanopart Res

123