Sumio Iijima Patents & Innovation Profile — PatSnap Eureka
Sumio Iijima: Patent Portfolio & Innovation Analysis
Sumio Iijima is a Japanese physicist and electron microscopist who holds 457 patents spanning carbon nanotube synthesis, encapsulation, and thermal management, with filings from 1993 to 2007. His portfolio is primarily assigned to the National Institute of Advanced Industrial Science and Technology (AIST) and covers foundational methods that underpin modern nanotechnology and nanocarbon materials science.
Patent Filing Activity
Peak activity in 2007, with 2 filings at AIST covering aligned CNT assemblies for thermal and electronic applications.
Sumio Iijima's Patent Filing Patterns
Iijima's sampled filing activity spans two distinct institutional phases — an NEC-era foundational patent in 1993 and AIST-era applied patents in 2007 — reflecting a career that bridged corporate and national laboratory R&D.
Annual Patent Filings
Peak year was 2007, with 2 filings at AIST covering aligned carbon nanotube assemblies for thermal and electronic device applications.
Technology Domain Breakdown
H01L23 (CNT thermal management) is the dominant IPC domain, accounting for 67% of sampled patents, followed by H01L39 superconductor-adjacent nanoelectronics.
Core Areas of Innovation
Sumio Iijima's patent portfolio centres on the structural design, synthesis, and functional application of carbon nanotubes — from foundational encapsulation chemistry to industrial-scale aligned CNT forest fabrication.
Carbon Nanotube Encapsulation & Functionalisation
1 patentThis domain covers the structural design of carbon nanotubules as hollow vessels capable of containing foreign materials — metals, molecules, or other nanostructures. Patents address how to open sealed nanotube tips and introduce guest materials while preserving structural integrity, constituting foundational prior art for drug delivery and nanoscale composite materials.
- Carbon nanotubule enclosing a foreign material (US5457343A)
- Multiple coaxially arranged graphite monoatomic sheets
- Quantum dot encapsulation and nanoscale composite design
Aligned CNT Assemblies for Thermal & Electronic Applications
2 patentsThis domain addresses fabrication of high-density, vertically aligned carbon nanotube forests for thermal management and electronic component applications. Patents cover CVD synthesis followed by liquid-contact densification to produce oriented multi-CNT aggregates with densities of 0.2–1.5 g/cm³, directly relevant to thermal interface materials in next-generation chip packaging.
- Aligned carbon nanotube monolithic aggregate and manufacturing method (CN101365650A)
- Single-walled CNT assembly with high density and hardness
- Thermal interface materials for semiconductor packaging
Superconductor-Adjacent Carbon Nanoelectronics
1 patentIPC code H01L39 encompasses devices exploiting superconductivity or employing superconducting elements, placing Iijima's earliest US patent at the intersection of carbon nanoelectronics and low-temperature device physics. This classification reflects scientific interest in the electronic transport properties of nanotubules as quasi-one-dimensional conductors.
- Carbon nanotubule electronic transport properties
- Quasi-one-dimensional conductor characterisation
- Low-temperature device physics applications
Sumio Iijima's Highest-Impact IP
US5457343A — filed in 1993 and attracting 177 citations — is a foundational prior art document for any technology involving the introduction of foreign materials into carbon nanotubes, spanning nanomedicine, semiconductor materials, energy storage, and advanced composites.
| Patent Number | Title | Year | Citations | Assignee | Status |
|---|---|---|---|---|---|
| US5457343A | Carbon nanotubule enclosing a foreign material | 1993 | 177 ↑ | NEC Corporation | Inactive |
| CN101365650A | Aligned carbon nanotube monolithic aggregate and manufacturing method | 2007 | 12 ↑ | AIST | Inactive |
Sumio Iijima's Research Collaborators
Most Frequent Co-Inventors
Collaboration Highlights
Iijima's co-inventor network reflects two distinct collaboration circles: his NEC-era partnership with Pulickel M. Ajayan — which produced the foundational nanotube encapsulation patent US5457343A — and his AIST-era core team of Hata Kenji, Futaba Don N., and Yumura Morio, who together developed the super-growth CVD platform for aligned CNT forest fabrication. Hata Kenji, the most frequent co-inventor with 6 joint patents, is also the lead author of the landmark 2004 Science paper on water-assisted CNT synthesis (1,875 citations).
- 畠贤治 (Hata Kenji) 6 joint patents
- HATA KENJI (variant record) 2 joint patents
- D·N·弗塔巴 (Futaba Don N.) 2 joint patents
- YUMURA MORIO 2 joint patents
- PULICKEL M. AJAYAN 1 joint patent
Research Literature by Sumio Iijima
285 papers indexed · Academic publication has been Iijima's primary vehicle for communicating discoveries, with his most cited works establishing foundational knowledge in CNT synthesis methodology, structural characterisation, and carbon nanohorn science.
| Title | Year | Citations | Institution |
|---|---|---|---|
| Water-Assisted Highly Efficient Synthesis of Impurity-Free Single-Walled Carbon Nanotubes | 2004 | 1,875 ↑ | AIST Research Center for Advanced Carbon Materials |
| Shape-engineerable and highly densely packed single-walled carbon nanotubes and their application as super-capacitor electrodes | 2006 | 1,329 ↑ | AIST Research Center for Advanced Carbon Materials |
| Size-selective growth of double-walled carbon nanotube forests from engineered iron catalysts | 2006 | 352 ↑ | AIST / NEC Corporation |
| Imaging active topological defects in carbon nanotubes | 2007 | 275 ↑ | AIST / ERATO-JST |
| Synthesis of Single- and Double-Walled Carbon Nanotube Forests on Conducting Metal Foils | 2006 | 172 ↑ | AIST / Meijo University |
CNT Synthesis Methodology
Most cited clusterThe water-assisted CVD super-growth platform developed at AIST with Hata Kenji enabled production of millimetre-tall, impurity-free nanotube forests. The 2004 Science paper (1,875 citations) is among the most influential results in the entire carbon nanotube field and directly underpins the 2007 CN patent family on aligned CNT assemblies.
CNT Structural Characterisation & Defect Physics
Electron microscopy expertiseLeveraging Iijima's unmatched expertise in high-resolution transmission electron microscopy (HRTEM) and STEM, this cluster includes the 2007 Nature Materials work on topological defects (275 citations), establishing structural knowledge that informs materials design across academic and industrial communities.
Carbon Nanohorn Science & Applications
Sustained 2000s–2020sA deliberate expansion of scope from nanotubes to the broader family of nanocarbon materials, this cluster covers fundamental structural analysis through to drug delivery, field emission devices, and biomedical imaging using single-walled carbon nanohorns (SWCNHs) — a structurally distinct carbon nanostructure with significant potential in energy storage.
Patent Jurisdictions
Iijima's sampled filings reflect a targeted rather than broadly defensive strategy — the 1993 US filing secured the world's largest technology market for the foundational encapsulation concept, while the 2007 China filings positioned AIST's aligned CNT assembly technology in a rapidly expanding electronics and advanced materials manufacturing market.
Filing Markets
The US filing (1993, NEC Corporation) targeted the world's largest patent market for the foundational nanotube encapsulation concept during the immediate post-discovery period. The China filings (2007, AIST) reflect deliberate commercial positioning in the Chinese electronics and advanced materials manufacturing market at a time when China was rapidly expanding its semiconductor and nanomaterials industries. The full 457-patent portfolio likely encompasses additional jurisdictions including Japan and Europe not represented in the base patent sample.
For complete jurisdiction coverage across all 457 patents, including JPO and EPO filings, search the full portfolio in PatSnap Eureka IP. See also the USPTO, EPO, and WIPO for official patent records.
Why Sumio Iijima's Portfolio Matters
Strategic implications for patent attorneys, in-house IP teams, and R&D strategists working in nanotechnology, semiconductor packaging, energy storage, and nanomedicine.
FTO Considerations
US5457343A, while now expired (December 2013), constitutes essential prior art for any technology involving the introduction of foreign materials into carbon nanotubes. Its expiry opens design space, but the patent's claim scope and extensive literature built around it define the boundaries of what was obvious at the priority date — directly relevant to patentability assessments for any new encapsulation or functionalisation approach. The CN101365650A family expired in January 2022, similarly opening commercial space in thermal interface materials and supercapacitor electrode design.
Prior Art Relevance
With 285 indexed papers, the academic record associated with Iijima is among the most consequential prior art bodies in all of nanotechnology. Any patent application touching CNT synthesis by CVD, nanotube alignment, water-assisted super-growth, nanohorn aggregation, or carbon nanotube structural modification must account for this literature in prior art searches and claim drafting. The 2004 Science water-assisted synthesis paper (1,875 citations) alone will surface as prior art against a broad range of synthesis and processing claims.
Sumio Iijima Patent Portfolio — Common Questions
Analyse Sumio Iijima's Full Patent Portfolio in PatSnap Eureka IP
Access all 457 patents, complete citation networks, co-inventor mapping, FTO analysis, and AI-powered prior art search across 208M+ patents and papers.
References & Further Reading
- US5457343A — Carbon nanotubule enclosing a foreign material (1993, NEC Corporation) · View in PatSnap Eureka IP · USPTO
- CN101365650A — Aligned carbon nanotube monolithic aggregate (2007, AIST) · View in PatSnap Eureka IP
- Water-Assisted Highly Efficient Synthesis of Impurity-Free Single-Walled Carbon Nanotubes (2004) · View paper
- European Patent Office (EPO) — Carbon nanotube patent landscape · epo.org
- WIPO — Global patent search and nanotechnology classification · wipo.int
- PatSnap Eureka IP — Full inventor portfolio analysis · eureka.patsnap.com
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