Potential applications of carbon nanotubes
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Carbon nanotubes (CNTs) are cylinders of one or more layers of graphene (lattice). Diameters of single-walled carbon nanotubes (SWNTs) and multi-walled carbon nanotubes (MWNTs) are typically 0.8 to 2 nm and 5 to 20 nm, respectively, although MWNT diameters can exceed 100 nm. CNT lengths range from less than 100 nm to 0.5 m.
Individual CNT walls can be metallic or semiconducting depending on the orientation of the lattice with respect to the tube axis, which is called chirality. MWNT's cross-sectional area offers an elastic modulus approaching 1 TPa and a tensile strength of 100 GPa, over 10-fold higher than any industrial fiber. MWNTs are typically metallic and can carry currents of up to 109 A cm−2. SWNTs can display thermal conductivity of 3500 W m−1 K−1, exceeding that of diamond.
As of 2013[update], carbon nanotube production exceeded several thousand tons per year, used for applications in energy storage, automotive parts, boat hulls, sporting goods, water filters, thin-film electronics, coatings, actuators and electromagnetic shields. CNT-related publications more than tripled in the prior decade, while rates of patent issuance also increased. Most output was of unorganized architecture. Organized CNT architectures such as "forests", yarns and regular sheets were produced in much smaller volumes. CNTs have even been proposed as the tether for a purported space elevator.
Recently, several studies have highlighted the prospect of using carbon nanotubes as building blocks to fabricate three-dimensional macroscopic (>1mm in all three dimensions) all-carbon devices. Lalwani et al. have reported a novel radical initiated thermal crosslinking method to fabricated macroscopic, free-standing, porous, all-carbon scaffolds using single- and multi-walled carbon nanotubes as building blocks. These scaffolds possess macro-, micro-, and nano- structured pores and the porosity can be tailored for specific applications. These 3D all-carbon scaffolds/architectures maybe used for the fabrication of the next generation of energy storage, supercapacitors, field emission transistors, high-performance catalysis, photovoltaics, and biomedical devices and implants.
- 1 Medicine
- 2 Composite materials
- 3 Microelectronics
- 4 Solar cells
- 5 Electronic components
- 6 Energy storage
- 7 Loudspeaker
- 8 Chemical
- 9 Mechanical
- 10 Optical
- 11 References
- 12 External links
Researchers from Rice University and State University of New York - Stony Brook have shown that the addition of low weight % of carbon nanotubes can lead to significant improvements in the mechanical properties of biodegradable polymeric nanocomposites for applications in bone tissue engineering. Dispersion of low weight % of graphene (~0.02 wt.%) results in significant increases in compressive and flexural mechanical properties of polymeric nanocomposites.
CNTs exhibit dimensional and chemical compatibility with biomolecules, such as DNA and proteins. CNTs enable fluorescent and photoacoustic imaging, as well as localized heating using near-infrared radiation.
SWNT biosensors exhibit large changes in electrical impedance and optical properties, which is typically modulated by adsorption of a target on the CNT surface. Low detection limits and high selectivity require engineering the CNT surface and field effects, capacitance, Raman spectral shifts and photoluminescence for sensor design. Products under development include printed test strips for estrogen and progesterone detection, microarrays for DNA and protein detection and sensors for NO
2 and cardiac troponin. Similar CNT sensors support food industry, military and environmental applications.
CNTs can be internalized by cells, first by binding their tips to cell membrane receptors. This enables transfection of molecular cargo attached to the CNT walls or encapsulated by CNTs. For example, the cancer drug doxorubicin was loaded at up to 60 wt % on CNTs compared with a maximum of 8 to 10 wt % on liposomes. Cargo release can be triggered by near-infrared radiation. However, limiting the retention of CNTs within the body is critical to prevent undesirable accumulation.
CNT toxicity remains a concern, although CNT biocompatibility may be engineerable. The degree of lung inflammation caused by injection of well-dispersed SWNTs was insignificant compared with asbestos and with particulate matter in air. Medical acceptance of CNTs requires understanding of immune response and appropriate exposure standards for inhalation, injection, ingestion and skin contact. CNT forests immobilized in a polymer did not show elevated inflammatory response in rats relative to controls. CNTs are under consideration as low-impedance neural interface electrodes and for coating of catheters to reduce thrombosis.
CNT enabled x-ray sources for medical imaging are also in development. Relying on the unique properties of the CNTs, researchers have developed field emission cathodes that allow precise x-ray control and close placement of multiple sources. CNT enabled x-ray sources have been demonstrated for pre-clinical, small animal imaging applications, and are currently in clinical trials.
MWNTs were first used as electrically conductive fillers in metals, at concentrations as high as 83.78 percent by weight (wt %). MWNT-polymer composites reach conductivities as high as 10,000 S m−1 at 10 wt % loading. In the automotive industry, CNT plastics are used in electrostatic-assisted painting of mirror housings, as well as fuel lines and filters that dissipate electrostatic charge. Other products include electromagnetic interference (EMI)–shielding packages and silicon wafer carriers.
For load-bearing applications, CNT powders are mixed with polymers or precursor resins to increase stiffness, strength and toughness. These enhancements depend on CNT diameter, aspect ratio, alignment, dispersion and interfacial interaction. Premixed resins and master batches employ CNT loadings from 0.1 to 20 wt %. Nanoscale stick-slip among CNTs and CNT-polymer contacts can increase material damping, enhancing sporting goods, including tennis racquets, baseball bats and bicycle frames.
CNT resins enhance fiber composites, including wind turbine blades and hulls for maritime security boats that are made by enhancing carbon fiber composites with CNT-enhanced resin. CNTs are deployed as additives in the organic precursors of stronger 1-μm diameter carbon fibers. CNTs influence the arrangement of carbon in pyrolyzed fiber.
Toward the challenge of organizing CNTs at larger scales, hierarchical fiber composites are created by growing aligned forests onto glass, silicon carbide (SiC), alumina and carbon fibers, creating so-called "fuzzy" fibers. Fuzzy epoxy CNT-SiC and CNT-alumina fabric showed 69% improved crack-opening (mode I) and/or in-plane shear interlaminar (mode II) toughness. Applications under investigation include lightning-strike protection, deicing, and structural health monitoring for aircraft.
MWNTs can be used as a flame-retardant additive to plastics due to changes in rheology by nanotube loading. Such additives can replace halogenated flame retardants, which face environmental restrictions.
Later, CNT yarns and laminated sheets made by direct chemical vapor deposition (CVD) or forest spinning or drawing methods may compete with carbon fiber for high-end uses, especially in weight-sensitive applications requiring combined electrical and mechanical functionality. Research yarns made from few-walled CNTs have reached a stiffness of 357 GPa and a strength of 8.8 GPa for a gauge length comparable to the millimeter-long CNTs within the yarn. Centimeter-scale gauge lengths offer only 2-GPa gravimetric strengths, matching that of Kevlar.
Because the probability of a critical flaw increases with volume, yarns may never achieve the strength of individual CNTs. However, CNT's high surface area may provide interfacial coupling that mitigates these deficiencies. CNT yarns can be knotted without loss of strength. Coating forest-drawn CNT sheets with functional powder before inserting twist yields weavable, braidable and sewable yarns containing up to 95 wt % powder. Uses include superconducting wires, battery and fuel cell electrodes and self-cleaning textiles.
As yet impractical fibers of aligned SWNTs can be made by coagulation-based spinning of CNT suspensions. Cheaper SWNTs or spun MWNTs are necessary for commercialization. Carbon nanotubes can be dissolved in superacids such as fluorosulfuric acid and drawn into fibers in dry jet-wet spinning.
DWNT-polymer composite yarns have been made by twisting and stretching ribbons of randomly oriented bundles of DWNTs thinly coated with polymeric organic compounds.
SWNT are in use as an experimental material for removable, structural bridge panels.
In 2015 researchers incorporated CNTs and graphene into spider silk, increasing its strength and toughness to a new record. They sprayed 15 Pholcidae spiders with water containing the nanotubes or flakes.The resulting silk had a fracture strength up to 5.4 GPa, a Young’s modulus up to 47.8 GPa and a toughness modulus up to 2.1 GPa, surpassing both synthetic polymeric high performance fibres (e.g. Kevlar49) and knotted fibers.
Stretched, aligned MWNT forests springs can achieve an energy density 10 times greater than that of steel springs, offering cycling durability, temperature insensitivity, no spontaneous discharge and arbitrary discharge rate. SWNT forests are expected to be able to store far more than MWNTs.
Adding small amounts of CNTs to metals increases tensile strength and modulus with potential in aerospace and automotive structures. Commercial aluminum-MWNT composites have strengths comparable to stainless steel (0.7 to 1 GPa) at one-third the density (2.6 g cm−3), comparable to more expensive aluminium-lithium alloys.
Coatings and Films
CNTs can serve as a multifunctional coating material. For example, paint/MWNT mixtures can reduce biofouling of ship hulls by discouraging attachment of algae and barnacles. They are a possible alternative to environmentally hazardous biocide-containing paints. Mixing CNTs into anticorrosion coatings for metals can enhance coating stiffness and strength and provide a path for cathodic protection.
CNTs provide a less expensive alternative to ITO for a range of consumer devices. Besides cost, CNT's flexible, transparent conductors offer an advantage over brittle ITO coatings for flexible displays. CNT conductors can be deposited from solution and patterned by methods such as screen printing. SWNT films offer 90% transparency and a sheet resistivity of 100 ohm per square. Such films are under development for thin-film heaters, such as for defrosting windows or sidewalks.
Carbon nanotubes forests and foams can also be coated with a variety of different materials to change their functionality and performance. Examples include silicon coated CNTs to create flexible energy-dense batteries, graphene coatings to create highly elastic aerogels and silicon carbide coatings to create a strong structural material for robust high-aspect-ratio 3D-micro architectures.
SWNTs are attractive for transistors because of their low electron scattering and their bandgap. SWNTs are compatible with field-effect transistor (FET) architectures and high-k dielectrics. Despite progress following the CNT transistor's appearance in 1998, including a tunneling FET with a subthreshold swing of <60 mV per decade (2004), a radio (2007) and an FET with sub-10-nm channel length and a normalized current density of 2.41 mA μm−1 at 0.5 V, greater than those obtained for silicon devices.
However, control of diameter, chirality, density and placement remains insufficient for commercial production. Less demanding devices of tens to thousands of SWNTs are more immediately practical. The use of CNT arrays/transistor increases output current and compensates for defects and chirality differences, improving device uniformity and reproducibility. For example, transistors using horizontally aligned CNT arrays achieved mobilities of 80 cm2 V−1 s−1, subthreshold slopes of 140 mV per decade and on/off ratios as high as 105. CNT film deposition methods enable conventional semiconductor fabrication of more than 10,000 CNT devices per chip.
Printed CNT thin-film transistors (TFTs) are attractive for driving organic light-emitting diode displays, showing higher mobility than amorphous silicon (~1 cm2 V−1 s−1) and can be deposited by low-temperature, nonvacuum methods. Flexible CNT TFTs with a mobility of 35 cm2 V−1 s−1 and an on/off ratio of 6×106 were demonstrated. A vertical CNT FET showed sufficient current output to drive OLEDs at low voltage, enabling red-green-blue emission through a transparent CNT network. CNTs are under consideration for radio-frequency identification tags. Selective retention of semiconducting SWNTs during spin-coating and reduced sensitivity to adsorbates were demonstrated.
The International Technology Roadmap for Semiconductors suggests that CNTs could replace Cu in microelectronic interconnects, owing to their low scattering, high current-carrying capacity, and resistance to electromigration. For this, vias comprising tightly packed (>1013 cm−2) metallic CNTs with low defect density and low contact resistance are needed. Recently, complementary metal oxide semiconductor (CMOS)–compatible 150-nm-diameter interconnects with a single CNT–contact hole resistance of 2.8 kOhm were demonstrated on full 200-mm-diameter wafers. Also, as a replacement for solder bumps, CNTs can function both as electrical leads and heat dissipaters for use in high-power amplifiers.
Last, a concept for a nonvolatile memory based on individual CNT crossbar electromechanical switches has been adapted for commercialization by patterning tangled CNT thin films as the functional elements. This required development of ultrapure CNT suspensions that can be spin-coated and processed in industrial clean room environments and are therefore compatible with CMOS processing standards.
Carbon nanotube field-effect transistors (CNTFETs) can operate at room temperature and are capable of digital switching using a single electron. In 2013, a CNT logic circuit was demonstrated that could perform useful work. Major obstacles to nanotube-based microelectronics include the absence of technology for mass production, circuit density, positioning of individual electrical contacts, sample purity, control over length, chirality and desired alignment, thermal budget and contact resistance.
Another way to make transistors is using random nanotube networks. Doing so averages their electrical differences enabling device creation at the wafer level.
Since the electron mean free path in SWCNTs can exceed 1 micrometer, long channel CNTFETs exhibit near-ballistic transport characteristics, resulting in high speeds. CNT devices are projected to operate in the frequency range of hundreds of gigahertz.
Nanotubes can be grown on nanoparticles of magnetic metal (Fe, Co) that facilitates production of electronic (spintronic) devices. In particular control of current through a field-effect transistor by magnetic field has been demonstrated in such a single-tube nanostructure.
In 2001 IBM researchers demonstrated how metallic nanotubes can be destroyed, leaving semiconducting nanotubes for use as components. Using "constructive destruction", they destroyed defective nanotubes on the wafer. This process, however, only gives control over the electrical properties on a statistical scale. In 2003 room-temperature ballistic transistors with ohmic metal contacts and high-k gate dielectric were reported, showing 20–30x more current than state-of-the-art siliconMOSFETs. Palladium is a high-work function metal that was shown to exhibit Schottky barrier-free contacts to semiconducting nanotubes with diameters >1.7 nm.
The first nanotube integrated memory circuit was made in 2004.
In 2014 networks of purified semiconducting carbon nanotubes were used as the active material in p-type thin film transistors. They were created using 3-D printers using inkjet or gravure methods on flexible substrates, including polyimide and polyethylene (PET) and transparent substrates such as glass. These transistors reliably exhibit high-mobilities (> 10 cm2 V−1 s−1) and ON/OFF ratios (> 1000) as well as threshold voltages below 5 V. They offer current density and low power consumption as well as environmental stability and mechanical flexibility. Hysterisis in the current-voltage curses as well as variability in the threshold voltage remain to be solved.
In 2015 researchers announced a new way to connect wires to SWNTs that make it possible to continue shrinking the width of the wires without increasing electrical resistance. The advance was expected to shrink the contact point between the two materials to just 40 atoms in width and later less. They tubes align in regularly spaced rows on silicon wafers. Simluations indicated that designs could be optimized either for high performance or for low power consumption. Commercial devices were not expected until the 2020s.
Large CNT structures can be used for thermal management of electronic circuits. An approximately 1 mm – thick CNT layer was used as a special material to fabricate coolers, this material has low density, ~20 times lower weight than a similar copper structure, but with similar cooling properties. In 2013, researchers demonstrated a Turing-complete prototype micrometer-scale computer. Carbon nanotube transistors as logic-gate circuits have not reached densities comparable to CMOS technology.
Single-walled nanotubes (SWNTs) have potential for use in photovoltaic panels, due to their strong ultraviolet/Vis-NIR absorption characteristics. Solar cells developed at the New Jersey Institute of Technology use a mixture of CNTs and fullerenes to form snake-like structures. Fullerenes trap electrons while nanotubes conduct them out of the cell.
Combining SWNT's with photexcitable electron donors can increase the number of electrons generated. The interaction between the photoexcited porphyrin and SWNT generates electro-hole pairs at the SWNT surfaces, at 8.5% efficiency.
SWNT's capillary effects can be used to condense gases to high density. This allows for gases, most notably hydrogen (H
2), to be stored at high densities without condensation into liquid form. Potentially, this method could support a hydrogen-powered car. Current storage methods involve liquifying the gas, which costs 25–45% of the potential energy. SWNT storage yields a volume to energy ratio slightly smaller than that of gasoline, allowing comparable range.
An area of controversy and frequent experimentation regarding the storage of hydrogen by adsorption in carbon nanotubes is the efficiency by which this process occurs. The effectiveness of hydrogen storage is integral to its use as a primary fuel source since hydrogen only contains about one fourth the energy per unit volume as gasoline.
One experiment sought to determine the amount of hydrogen stored in CNTs by utilizing elastic recoil detection analysis (ERDA). CNTs (primarily SWNTs) were synthesized via chemical vapor disposition (CVD) and subjected to a two-stage purification process including air oxidation and acid treatment, then formed into flat, uniform discs and exposed to pure, pressurized hydrogen at various temperatures. When the data was analyzed, it was found that the ability of CNTs to store hydrogen decreased as temperature increased. Moreover, the highest hydrogen concentration measured was ~0.18%; significantly lower than commercially viable hydrogen storage needs to be.
In another experiment, CNTs were synthesized via CVD and their structure was characterized using Raman spectroscopy. Utilizing microwave digestion, the samples were exposed to different acid concentrations and different temperatures for various amounts of time in an attempt to find the optimum purification method for SWNTs of the diameter determined earlier. The purified samples were then exposed to hydrogen gas at various high pressures, and their adsorption by weight percent was plotted. The data showed that hydrogen adsorption levels of up to 3.7% are possible with a very pure sample and under the proper conditions. It is thought that microwave digestion helps improve the hydrogen adsorption capacity of the CNTs by opening up the ends, allowing access to the inner cavities of the nanotubes.
Limitations on efficient hydrogen adsorption
The biggest obstacle to efficient hydrogen storage using CNTs is the purity of the nanotubes. To achieve maximum hydrogen adsorption, there must be minimum graphene, amorphous carbon, and metallic deposits in the nanotube sample. Current methods of CNT synthesis require a purification step. However, even with pure nanotubes, the adsorption capacity is only maximized under high pressures, which are undesirable in commercial fuel tanks.
Various companies are developing transparent, electrically conductive CNT films and nanobuds to replace indium tin oxide (ITO) in LCDs, touch screens and photovoltaic devices. Nanotube films show promise for use in displays for computers, cell phones, Personal digital assistants, and automated teller machines. CNT diodes display a photovoltaic effect.
Multi-walled nanotubes (MWNT coated with magnetite) can generate strong magnetic fields. Recent advances show that MWNT decorated with maghemite nanoparticles can be oriented in a magnetic field and enhance the electrical properties of the composite material in the direction of the field for use in electric motor brushes.
CNTs can be used as electron guns in miniature cathode ray tubes (CRT) in high-brightness, low-energy, low-weight displays. A display would consist of a group of tiny CRTs, each providing the electrons to illuminate the phosphor of one pixel, instead of having one CRT whose electrons are aimed using electric and magnetic fields. These displays are known as field emission displays (FEDs).
Conductive CNTs are used in brushes for commercial electric motors. They replace traditional carbon black. The nanotubes improve electrical and thermal conductivity because they stretch through the plastic matrix of the brush. This permits the carbon filler to be reduced from 30% down to 3.6%, so that more matrix is present in the brush. Nanotube composite motor brushes are better-lubricated (from the matrix), cooler-running (both from better lubrication and superior thermal conductivity), less brittle (more matrix, and fiber reinforcement), stronger and more accurately moldable (more matrix). Since brushes are a critical failure point in electric motors, and also don't need much material, they became economical before almost any other application.
Wires for carrying electric current may be fabricated from nanotubes and nanotube-polymer composites. Small wires have been fabricated with specific conductivity exceeding copper and aluminum; the highest conductivity non-metallic cables.
Metallic carbon nanotubes have aroused research interest for their applicability as very-large-scale integration (VLSI) interconnects because of their high thermal stability, high thermal conductivity and large current carrying capacity. An isolated CNT can carry current densities in excess of 1000 MA/sq-cm without damage even at an elevated temperature of 250 °C (482 °F), eliminating electromigration reliability concerns that plague Cu interconnects. Recent modeling work comparing the two has shown that CNT bundle interconnects can potentially offer advantages over copper. Recent experiments demonstrated resistances as low as 20 Ohms using different architectures, detailed conductance measurements over a wide temperature range were shown to agree with theory for a strongly disordered quasi-one-dimensional conductor.
Hybrid interconnects that employ CNT vias in tandem with copper interconnects offers advantages from a reliability/thermal-management perspective.
MWNTs are used in lithium ion batteries. In these batteries, small amounts of MWNT powder are blended with active materials and a polymer binder, such as 1 wt % CNT loading in LiCoO
2 cathodes and graphite anodes. CNTs provide increased electrical connectivity and mechanical integrity, which enhances rate capability and cycle life.
A 40-F supercapacitor with a maximum voltage of 3.5 V that employed forest-grown SWNTs that are binder- and additive-free achieved an energy density of 15.6 Wh kg−1 and a power density of 37 kW kg−1. CNTs can be bound to the charge plates of capacitors to dramatically increase the surface area and therefore energy density.
CNTs in organic solar cells help reduce energy loss (carrier recombination) and enhance resistance to photooxidation. Photovoltaic technologies may someday incorporate CNT-Silicon heterojunctions to leverage efficient multiple-exciton generation at p-n junctions formed within individual CNTs. In the nearer term, commercial photovoltaics may incorporate transparent SWNT electrodes.
A paper battery is a battery engineered to use a paper-thin sheet of cellulose infused with CNT. The nanotubes act as electrodes; allowing the storage devices to conduct electricity. The battery, which functions as both a lithium-ion battery and a supercapacitor, can provide a long, steady power output comparable to a conventional battery, as well as a supercapacitor’s quick burst of high power—and while a conventional battery contains a number of separate components, the paper battery integrates battery components in a single structure.
Parallel CNT have been used to create loudspeakers from CNT sheets, using a mechanism similar to how lightning produces thunder. Near-term commercial uses include replacing piezoelectric speakers in greeting cards.
CNT can be used for desalination. Water molecules can be separated from salt by forcing them through electrochemically robust nanotube networks with controlled nanoscale porosity. This process requires far lower pressures than conventional reverse osmosis methods. Compared to a plain membrane, it operates at a 20 °C lower temperature, and at a 6x greater flow rate. Membranes using aligned, encapsulated CNTs with open ends permit flow through the CNTs' interiors. Very-small-diameter SWNTs are needed to reject salt at seawater concentrations. Portable filters containing CNT meshes can purify contaminated drinking water. Such networks can electrochemically oxidize organic contaminants, bacteria and viruses.
CNT have the potential to store between 4.2 and 65% hydrogen by weight. If they can be mass-produced economically, 13.2 litres (2.9 imp gal; 3.5 US gal) of CNT could contain the same amount of energy as a 50 litres (11 imp gal; 13 US gal) gasoline tank.
CNTs can be used to produce nanowires of other elements/molecules, such as gold or zinc oxide. Nanowires in turn can be used to cast nanotubes of other materials, such as gallium nitride. These can have very different properties from CNTs—for example, gallium nitride nanotubes are hydrophilic, while CNTs are hydrophobic, giving them possible uses in organic chemistry.
Oscillators based on CNT have achieved speeds of > 50 GHz.
CNT electrical and mechanical properties suggest them as alternatives to traditional electrical actuators.
- See additional applications in: Optical properties of carbon nanotubes
- Carbon nanotube photoluminescence (fluorescence) can be used to observe semiconducting single-walled carbon nanotube species. Photoluminescence maps, made by acquiring the emission and scanning the excitation energy, can facilitate sample characterization.
- The reflectivity of buckypaper produced with "super-growth" chemical vapor deposition is 0.03 or less, potentially enabling performance gains for pyroelectric infrared detectors.
- Zhang, R.; Zhang, Y.; Zhang, Q.; Xie, H.; Qian, W.; Wei, F. (2013). "Growth of Half-Meter Long Carbon Nanotubes Based on Schulz–Flory Distribution". ACS Nano volume = 7 (7): 6156–61. doi:10.1021/nn401995z. PMID 23806050.
- De Volder, M. F. L.; Tawfick, S. H.; Baughman, R. H.; Hart, A. J. (2013). "Carbon Nanotubes: Present and Future Commercial Applications". Science 339 (6119): 535–539. doi:10.1126/science.1222453. PMID 23372006.
- "Supplementary Materials". Sciencemag.org. 2013-02-01. doi:10.1126/science.1222453. Retrieved 2014-04-09.
- F1 image
- Edwards, Brad C. (2003). The Space Elevator. BC Edwards. ISBN 0-9746517-1-0.
- Collins, P.G. (2000). "Nanotubes for Electronics" (PDF). Scientific American: 67–69.
Zhang, M.; Fang, S; Zakhidov, AA; Lee, SB; Aliev, AE; Williams, CD; Atkinson, KR; Baughman, RH (2005). "Strong, Transparent, Multifunctional, Carbon Nanotube Sheets". Science 309 (5738): 1215–1219. Bibcode:2005Sci...309.1215Z. doi:10.1126/science.1115311. PMID 16109875.
- Lalwani, Gaurav; Kwaczala, Andrea Trinward; Kanakia, Shruti; Patel, Sunny C.; Judex, Stefan; Sitharaman, Balaji (2013). "Fabrication and characterization of three-dimensional macroscopic all-carbon scaffolds". Carbon 53: 90–100. doi:10.1016/j.carbon.2012.10.035. PMC 3578711. PMID 23436939.
- Lalwani, Gaurav; Henslee, Allan M.; Farshid, Behzad; Lin, Liangjun; Kasper, F. Kurtis; Qin, Yi-Xian; Mikos, Antonios G.; Sitharaman, Balaji (2013). "Two-dimensional nanostructure-reinforced biodegradable polymeric nanocomposites for bone tissue engineering". Biomacromolecules 14 (3): 900–909. doi:10.1021/bm301995s. PMC 3601907. PMID 23405887.
- Lalwani, Gaurav (September 2013). "Tungsten disulfide nanotubes reinforced biodegradable polymers for bone tissue engineering". Acta Biomaterialia 9 (9): 8365–8373. doi:10.1016/j.actbio.2013.05.018. PMC 3732565. PMID 23727293.
- Nasibulin, A. G.; Shandakov, S. D.; Nasibulina, L. I.; Cwirzen, A.; Mudimela, P. R.; Habermehl-Cwirzen, K.; Grishin, D. A.; Gavrilov, Y. V.; Malm, J. E. M.; Tapper, U.; Tian, Y.; Penttala, V.; Karppinen, M. J.; Kauppinen, E. I. (2009). "A novel cement-based hybrid material". New Journal of Physics 11 (2): 023013. doi:10.1088/1367-2630/11/2/023013.
- Zhao, Z.; Gou, J. (2009). "Improved fire retardancy of thermoset composites modified with carbon nanofibers". Science and Technology of Advanced Materials 10: 015005. doi:10.1088/1468-6996/10/1/015005.
- Proceedings of the 7th Aachen-Dresden International Textile Conference, November 28–29, 2013, Aachen, Germany.
- Yang, Y.; Chen, X.; Shao, Z.; Zhou, P.; Porter, D.; Knight, D. P.; Vollrath, F. (2005). "Toughness of Spider Silk at High and Low Temperatures". Advanced Materials 17: 84–88. doi:10.1002/adma.200400344.
Naraghi, Mohammad; Filleter, Tobin; Moravsky, Alexander; Locascio, Mark; Loutfy, Raouf O.; Espinosa, Horacio D. (2010). "A Multiscale Study of High Performance Double-Walled Nanotube−Polymer Fibers". ACS Nano 4 (11): 6463–6476. doi:10.1021/nn101404u. PMID 20977259.
- "MIT Institute For Soldier Nanotechnologies". Web.mit.edu. Retrieved 2010-02-26.
- Rincon, Paul (2007-10-23). "Science/Nature | Super-strong body armour in sight". BBC News. Retrieved 2010-02-26.
Yildirim, T.; Gülseren, O.; Kılıç, Ç.; Ciraci, S. (2000). "Pressure-induced interlinking of carbon nanotubes". Phys. Rev. B 62 (19): 19. arXiv:cond-mat/0008476. Bibcode:2000PhRvB..6212648Y. doi:10.1103/PhysRevB.62.12648.
- Aliev, A. E.; Oh, J.; Kozlov, M. E.; Kuznetsov, A. A.; Fang, S.; Fonseca, A. F.; Ovalle, R.; Lima, M. D.; Haque, M. H.; Gartstein, Y. N.; Zhang, M.; Zakhidov, A. A.; Baughman, R. H. (2009). "Giant-Stroke, Superelastic Carbon Nanotube Aerogel Muscles". Science 323 (5921): 1575–8. doi:10.1126/science.1168312. PMID 19299612.
- "Composite Bridge Deck to Test Nanotube Technology | Composites Manufacturing Online". Compositesmanufacturingblog.com. 2009-10-19. Retrieved 2013-12-18.
- "Spiders Ingest Nanotubes, Then Weave Silk Reinforced with Carbon". Technology Review. May 6, 2015. Retrieved May 2015.
- Post to your group(s). "Carbon Nanotube Super Springs". ASME. Retrieved 2013-12-18.
- Fu, K. (1 Aug 2013). "Aligned Carbon Nanotube-Silicon Sheets: A Novel Nano-architecture for Flexible Lithium Ion Battery Electrodes". Advanced Materials 25 (36): 5109–5114. doi:10.1002/adma.201301920.
- Kim, K.H. (22 July 2012). "Graphene coating makes carbon nanotube aerogels superelastic and resistant to fatigue". Nature Nanotechnology 7 (9): 562–566. doi:10.1038/nnano.2012.118.
- Poelma, R.H. (17 Jul 2014). "Tailoring the Mechanical Properties of High-Aspect-Ratio Carbon Nanotube Arrays using Amorphous Silicon Carbide Coatings". Advanced Functional Materials 24 (36): 5737–5744. doi:10.1002/adfm.201400693.
- Postma, Henk W. Ch.; Teepen, T; Yao, Z; Grifoni, M; Dekker, C (2001). "Carbon Nanotube Single-Electron Transistors at Room temperature". Science 293 (5527): 76–9. Bibcode:2001Sci...293...76P. doi:10.1126/science.1061797. PMID 11441175.
- Bourzac, Katherine (2013-02-27). "Stanford University Researchers Make Complex Carbon Nanotube Circuits | MIT Technology Review". Technologyreview.com. Retrieved 2013-12-14.
- Talbot, David (2013-02-05). "IBM Creates a New Way to Make Faster and Smaller Transistors | MIT Technology Review". Technologyreview.com. Retrieved 2013-12-14.
- Gabriel, Jean-Christophe P. (2003). "Large Scale Production of Carbon Nanotube Transistors: A Generic Platforms for Chemical Sensors". Mat. Res. Soc. Symp. Proc. 762: Q.12.7.1.
Nanōmix – Breakthrough Detection Solutions with the Nanoelectronic Sensation Technology. Nano.com. Retrieved on 2012–06–06.
US patent US20070140946
Bradley, Keith; Gabriel, Jean-Christophe P.; Grüner, George (2003). "Flexible nanotube transistors". Nano Letters 3 (10): 1353–1355. Bibcode:2003NanoL...3.1353B. doi:10.1021/nl0344864.
Armitage, Peter N. "Flexible nanostructure electronic devices". United States Patent 20050184641 A1.
- Miller, J. T.; Lazarus, A.; Audoly, B.; Reis, P. M. (2014). "Shapes of a Suspended Curly Hair". Physical Review Letters 112 (6). doi:10.1103/PhysRevLett.112.068103.
- Hasan, S.; Salahuddin, S.; Vaidyanathan, M.; Alam, M. A. (2006). "High-frequency performance projections for ballistic carbon-nanotube transistors". IEEE Transactions on Nanotechnology 5: 14. doi:10.1109/TNANO.2005.858594.
- Appenzeller, J.; Lin, Y. -M.; Knoch, J.; Chen, Z.; Avouris, P. (2005). "Comparing Carbon Nanotube Transistors—The Ideal Choice: A Novel Tunneling Device Design". IEEE Transactions on Electron Devices 52 (12): 2568. doi:10.1109/TED.2005.859654.
- Wind, S. J.; Appenzeller, J.; Martel, R.; Derycke, V.; Avouris, P. (2002). "Vertical scaling of carbon nanotube field-effect transistors using top gate electrodes". Applied Physics Letters 80 (20): 3817. doi:10.1063/1.1480877.
- Chen, Z.; Appenzeller, J; Lin, Y. M.; Sippel-Oakley, J; Rinzler, A. G.; Tang, J; Wind, S. J.; Solomon, P. M.; Avouris, P (2006). "An Integrated Logic Circuit Assembled on a Single Carbon Nanotube". Science 311 (5768): 1735. doi:10.1126/science.1122797. PMID 16556834.
- Inami, N.; Ambri Mohamed, M.; Shikoh, E.; Fujiwara, A. (2007). "Synthesis-condition dependence of carbon nanotube growth by alcohol catalytic chemical vapor deposition method". Science and Technology of Advanced Materials 8 (4): 292. doi:10.1016/j.stam.2007.02.009.
- Collins, Philip G.; Arnold, MS; Avouris, P (2001). "Engineering Carbon Nanotubes and Nanotube Circuits Using Electrical Breakdown". Science 292 (5517): 706–709. Bibcode:2001Sci...292..706C. doi:10.1126/science.1058782. PMID 11326094.
- Javey, Ali; Guo, J; Wang, Q; Lundstrom, M; Dai, H (2003). "Ballistic Carbon Nanotube Transistors". Nature 424 (6949): 654–657. Bibcode:2003Natur.424..654J. doi:10.1038/nature01797. PMID 12904787.
Javey, Ali; Guo, Jing; Farmer, Damon B.; Wang, Qian; Yenilmez, Erhan; Gordon, Roy G.; Lundstrom, Mark; Dai, Hongjie (2004). "Self-aligned ballistic molecular transistors and electrically parallel nanotube arrays". Nano Letters 4 (7): 1319–1322. arXiv:cond-mat/0406494. Bibcode:2004NanoL...4.1319J. doi:10.1021/nl049222b.
- Tseng, Yu-Chih; Xuan, Peiqi; Javey, Ali; Malloy, Ryan; Wang, Qian; Bokor, Jeffrey; Dai, Hongjie (2004). "Monolithic Integration of Carbon Nanotube Devices with Silicon MOS Technology". Nano Letters 4: 123–127. Bibcode:2004NanoL...4..123T. doi:10.1021/nl0349707.
- Wang, C.; Chien, J. C.; Takei, K.; Takahashi, T.; Nah, J.; Niknejad, A. M.; Javey, A. (2012). "Extremely Bendable, High-Performance Integrated Circuits Using Semiconducting Carbon Nanotube Networks for Digital, Analog, and Radio-Frequency Applications". Nano Letters 12 (3): 1527–33. doi:10.1021/nl2043375. PMID 22313389.
- Lau, P. H.; Takei, K.; Wang, C.; Ju, Y.; Kim, J.; Yu, Z.; Takahashi, T.; Cho, G.; Javey, A. (2013). "Fully Printed, High Performance Carbon Nanotube Thin-Film Transistors on Flexible Substrates". Nano Letters 13 (8): 3864–9. doi:10.1021/nl401934a. PMID 23899052.
- Sajed, F.; Rutherglen, C. (2013). "All-printed and transparent single walled carbon nanotube thin film transistor devices". Applied Physics Letters 103 (14): 143303. doi:10.1063/1.4824475.]
- Markoff, John (2015-10-01). "IBM Scientists Find New Way to Shrink Transistors". The New York Times. ISSN 0362-4331. Retrieved 2015-10-02.
- Kordás, K.; TóTh, G.; Moilanen, P.; KumpumäKi, M.; VäHäKangas, J.; UusimäKi, A.; Vajtai, R.; Ajayan, P. M. (2007). "Chip cooling with integrated carbon nanotube microfin architectures". Appl. Phys. Lett. 90 (12): 123105. Bibcode:2007ApPhL..90l3105K. doi:10.1063/1.2714281.
- Lee, Robert. (2002–10–03) Build First Nanotube Computer – WSJ.com. Wall Street Journal. Retrieved on 2013–09–28.
Hsu, Jeremy. (2013–09–24) Carbon Nanotube Computer Hints at Future Beyond Silicon Semiconductors. Scientific American. Retrieved on 2013–09–28.
BBC News – First computer made of carbon nanotubes is unveiled. BBC. Retrieved on 2013–09–28.
- "New Flexible Plastic Solar Panels Are Inexpensive And Easy To Make". ScienceDaily. July 19, 2007.
- Guldi, Dirk M., G.M.A. Rahman, Maurizio Prato, Norbert Jux, Shubui Qin, and Warren Ford (2005). "Single-Wall Carbon Nanotubes as Integrative Building Blocks for Solar-Energy Conversion". Angewandte Chemie 117 (13): 2051–2054. doi:10.1002/ange.200462416. PMID 15724261.
- Li Zhongrui, Kunets Vasyl P., Saini Viney, and; et al. (2009). "Light-Harvesting Using High Density p-type Single Wall Carbon Nanotube/n-type Silicon Heterojunctions". ACS Nano 3 (6): 1407–1414. doi:10.1021/nn900197h.
- Dillon, A. C., K. M. Jones, T. A. Bekkedahl, C. H. Klang, D. S. Bethune, and M. J. Heben (1997). "Storage of hydrogen in single-walled carbon nanotubes". Nature 386 (6623): 377–379. Bibcode:1997Natur.386..377D. doi:10.1038/386377a0.
- Safa, S., Mojtahedzadeh Larijani, M., Fathollahi, V., Kakuee, O. R. (2010). "Investigating Hydrogen Storage Behavior of Carbon Nanotubes at Ambient Temperature and Above by Ion Beam Analysis". NANO 5 (6): 341–347. doi:10.1142/S1793292010002256.
- Yuca, N., Karatepe, N. (2011). "Hydrogen Storage in Single-Walled Carbon Nanotubes Purified by Microwave Digestion Method". World Academy of Science, Engineering and Technology 79: 605–610.
- "Canatu Oy". Canatu.com. Retrieved 2013-12-14.
"Makers of carbon nanotubes and films". Unidym. 2011-12-05. Retrieved 2013-12-14.
- Kim, I. T.; Nunnery, G. A.; Jacob, K.; Schwartz, J.; Liu, X.; Tannenbaum, R. (2010). "Synthesis, Characterization, and Alignment of Magnetic Carbon Nanotubes Tethered with Maghemite Nanoparticles". The Journal of Physical Chemistry C 114 (15): 6944. doi:10.1021/jp9118925.
- Kim, I. T.; Tannenbaum, A.; Tannenbaum, R. (2011). "Anisotropic conductivity of magnetic carbon nanotubes embedded in epoxy matrices". Carbon 49 (1): 54–61. doi:10.1016/j.carbon.2010.08.041. PMC 3457806. PMID 23019381.
- Tseng, S. H.; Tai, N. H.; Hsu, W. K.; Chen, L. J.; Wang, J. H.; Chiu, C. C.; Lee, C. Y.; Chou, L. J.; Leou, K. C. (2007). "Ignition of carbon nanotubes using a photoflash". Carbon 45 (5): 958. doi:10.1016/j.carbon.2006.12.033.
- The World's Smallest Radio: A Single Carbon Nanotube Can Function As A Radio That Detects And Plays Songs
- on YouTube
- Zhao, Yao; Wei, Jinquan; Vajtai, Robert; Ajayan, Pulickel M.; Barrera, Enrique V. (September 6, 2011). "Iodine doped carbon nanotube cables exceeding specific electrical conductivity of metals". Scientific Reports (Nature) 1. Bibcode:2011NatSR...1E..83Z. doi:10.1038/srep00083.
- Kreupl, F.; Graham, A. P.; Duesberg, G. S.; Steinhögl, W.; Liebau, M.; Unger, E.; Hönlein, W. (2002). "Carbon nanotubes in interconnect applications". Microelectronic Engineering 64: 399. doi:10.1016/S0167-9317(02)00814-6.
- Li, J.; Ye, Q.; Cassell, A.; Ng, H. T.; Stevens, R.; Han, J.; Meyyappan, M. (2003). "Bottom-up approach for carbon nanotube interconnects". Applied Physics Letters 82 (15): 2491. doi:10.1063/1.1566791.
- Srivastava, N.; Banerjee, K. (2005). "Performance analysis of carbon nanotube interconnects for VLSI applications". ICCAD-2005. IEEE/ACM International Conference on Computer-Aided Design, 2005. p. 383. doi:10.1109/ICCAD.2005.1560098. ISBN 0-7803-9254-X.
- Srivastava, N.; Joshi, R. V.; Banerjee, K. (2005). "Carbon nanotube interconnects: Implications for performance, power dissipation and thermal management". IEEE International Electron Devices Meeting, 2005. IEDM Technical Digest. p. 249. doi:10.1109/IEDM.2005.1609320. ISBN 0-7803-9268-X.
- Banerjee, K.; Srivastava, N. (2006). "Are carbon nanotubes the future of VLSI interconnections?". 2006 43rd ACM/IEEE Design Automation Conference. p. 809. doi:10.1109/DAC.2006.229330. ISBN 1-59593-381-6.
- Banerjee, K.; Im, S.; Srivastava, N. (2006). "Can Carbon Nanotubes Extend the Lifetime of On-Chip Electrical Interconnections?". 2006 1st International Conference on Nano-Networks and Workshops. p. 1. doi:10.1109/NANONET.2006.346235. ISBN 1-4244-0390-1.
- Naeemi, A.; Meindl, J. D. (2007). "Carbon nanotube interconnects". Proceedings of the 2007 international symposium on Physical design - ISPD '07. p. 77. doi:10.1145/1231996.1232014. ISBN 9781595936134.
- Coiffic, J.C.; Fayolle, M.; Maitrejean, S.; Foa Torres, L.E.F.; Le Poche, H. (2007). "Conduction regime in innovative carbon nanotube via interconnect architectures". Appl. Phys. Lett. 91 (25): 252107. Bibcode:2007ApPhL..91y2107C. doi:10.1063/1.2826274.
- Energy Exploration Energy Efficiency Energy Management. "Five World Records. One Cool Technology.". FastCap Systems. Retrieved 2013-12-18.
- "Beyond Batteries: Storing Power in a Sheet of Paper". Eurekalert.org. August 13, 2007. Retrieved 2008-09-15.
- "Folded paper lithium-ion battery increases energy density by 14 times". ExtremeTech. 2013-10-09. Retrieved 2013-12-18.
- Choi, C. (2008). "Nanotubes turn on the tunes". Nature. doi:10.1038/news.2008.1201.
- "New desalination process developed using carbon nanotubes". Sciencedaily.com. 2011-03-15. Retrieved 2013-12-14.
- R. B. Weisman and S. M. Bachilo (2003). "Dependence of Optical Transition Energies on Structure for Single-Walled Carbon Nanotubes in Aqueous Suspension: An Empirical Kataura Plot". Nano Letters 3 (9): 1235–1238. Bibcode:2003NanoL...3.1235W. doi:10.1021/nl034428i.
- Paul Cherukuri, Sergei M. Bachilo, Silvio H. Litovsky, and R. Bruce Weisman (2004). "Near-Infrared Fluorescence Microscopy of Single-Walled Carbon Nanotubes in Phagocytic Cells". Journal of the American Chemical Society 126: 15638–15639. doi:10.1021/ja0466311.
- Kevin Welsher, Sarah P. Sherlock, and Hongjie Dai (2011). "Deep-tissue anatomical imaging of mice using carbon nanotube fluorophores in the second near-infrared window". Proceedings of the National Academy of Sciences 108 (22): 8943–8948. arXiv:1105.3536. Bibcode:2011PNAS..108.8943W. doi:10.1073/pnas.1014501108.
- Paul W. Barone, Seunghyun Baik, Daniel A. Heller, and Michael S. Strano (2005). "Near-infrared optical sensors based on single-walled carbon nanotubes". Nature Materials 4: 86–92. Bibcode:2005NatMa...4...86B. doi:10.1038/nmat1276.
- AIST nanotech 2009
K. Mizuno; et al. (2009). "A black body absorber from vertically aligned single-walled carbon nanotubes". Proceedings of the National Academy of Sciences 106 (15): 6044–6077. Bibcode:2009PNAS..106.6044M. doi:10.1073/pnas.0900155106. PMC 2669394. PMID 19339498.