Unconventional supercapacitors from nanocarbon-based electrode materials to device configurations.

PubMed

Liu, Lili; Niu, Zhiqiang; Chen, Jun

2016-07-25

As energy storage devices, supercapacitors that are also called electrochemical capacitors possess high power density, excellent reversibility and long cycle life. The recent boom in electronic devices with different functions in transparent LED displays, stretchable electronic systems and artificial skin has increased the demand for supercapacitors to move towards light, thin, integrated macro- and micro-devices with transparent, flexible, stretchable, compressible and/or wearable abilities. The successful fabrication of such supercapacitors depends mainly on the preparation of innovative electrode materials and the design of unconventional supercapacitor configurations. Tremendous research efforts have been recently made to design and construct innovative nanocarbon-based electrode materials and supercapacitors with unconventional configurations. We review here recent developments in supercapacitors from nanocarbon-based electrode materials to device configurations. The advances in nanocarbon-based electrode materials mainly include the assembly technologies of macroscopic nanostructured electrodes with different dimensions of carbon nanotubes/nanofibers, graphene, mesoporous carbon, activated carbon, and their composites. The electrodes with macroscopic nanostructured carbon-based materials overcome the issues of low conductivity, poor mechanical properties, and limited dimensions that are faced by conventional methods. The configurational design of advanced supercapacitor devices is presented with six types of unconventional supercapacitor devices: flexible, micro-, stretchable, compressible, transparent and fiber supercapacitors. Such supercapacitors display unique configurations and excellent electrochemical performance at different states such as bending, stretching, compressing and/or folding. For example, all-solid-state simplified supercapacitors that are based on nanostructured graphene composite paper are able to maintain 95% of the original capacity at a 180° folding state. The progress made so far will guide further developments in the structural design of nanocarbon-based electrode materials and the configurational diversity of supercapacitor devices. Future developments and prospects in the controllable assembly of macroscopic nanostructured electrodes and the innovation of unconventional supercapacitor configurations are also discussed. This should shed light on the R&D of supercapacitors.

Suppression of tritium retention in remote areas of ITER by nonperturbative reactive gas injection.

PubMed

Tabarés, F L; Ferreira, J A; Ramos, A; van Rooij, G; Westerhout, J; Al, R; Rapp, J; Drenik, A; Mozetic, M

2010-10-22

A technique based on reactive gas injection in the afterglow region of the divertor plasma is proposed for the suppression of tritium-carbon codeposits in remote areas of ITER when operated with carbon-based divertor targets. Experiments in a divertor simulator plasma device indicate that a 4  nm/min deposition can be suppressed by addition of 1  Pa·m³ s⁻¹ ammonia flow at 10 cm from the plasma. These results bolster the concept of nonperturbative scavenger injection for tritium inventory control in carbon-based fusion plasma devices, thus paving the way for ITER operation in the active phase under a carbon-dominated, plasma facing component background.

Coupling carbon nanomaterials with photochromic molecules for the generation of optically responsive materials

PubMed Central

Zhang, Xiaoyan; Hou, Lili; Samorì, Paolo

2016-01-01

Multifunctional carbon-based nanomaterials offer routes towards the realization of smart and high-performing (opto)electronic (nano)devices, sensors and logic gates. Meanwhile photochromic molecules exhibit reversible transformation between two forms, induced by the absorption of electromagnetic radiation. By combining carbon-based nanomaterials with photochromic molecules, one can achieve reversible changes in geometrical structure, electronic properties and nanoscale mechanics triggering by light. This thus enables a reversible modulation of numerous physical and chemical properties of the carbon-based nanomaterials towards the fabrication of cognitive devices. This review examines the state of the art with respect to these responsive materials, and seeks to identify future directions for investigation. PMID:27067387

Carbon-Based Nanomaterials in Biomass-Based Fuel-Fed Fuel Cells

PubMed Central

Vestergaard, Mun’delanji C.; Tamiya, Eiichi

2017-01-01

Environmental and sustainable economical concerns are generating a growing interest in biofuels predominantly produced from biomass. It would be ideal if an energy conversion device could directly extract energy from a sustainable energy resource such as biomass. Unfortunately, up to now, such a direct conversion device produces insufficient power to meet the demand of practical applications. To realize the future of biofuel-fed fuel cells as a green energy conversion device, efforts have been devoted to the development of carbon-based nanomaterials with tunable electronic and surface characteristics to act as efficient metal-free electrocatalysts and/or as supporting matrix for metal-based electrocatalysts. We present here a mini review on the recent advances in carbon-based catalysts for each type of biofuel-fed/biofuel cells that directly/indirectly extract energy from biomass resources, and discuss the challenges and perspectives in this developing field. PMID:29125564

Carbon-Based Nanomaterials in Biomass-Based Fuel-Fed Fuel Cells.

PubMed

Hoa, Le Quynh; Vestergaard, Mun'delanji C; Tamiya, Eiichi

2017-11-10

Environmental and sustainable economical concerns are generating a growing interest in biofuels predominantly produced from biomass. It would be ideal if an energy conversion device could directly extract energy from a sustainable energy resource such as biomass. Unfortunately, up to now, such a direct conversion device produces insufficient power to meet the demand of practical applications. To realize the future of biofuel-fed fuel cells as a green energy conversion device, efforts have been devoted to the development of carbon-based nanomaterials with tunable electronic and surface characteristics to act as efficient metal-free electrocatalysts and/or as supporting matrix for metal-based electrocatalysts. We present here a mini review on the recent advances in carbon-based catalysts for each type of biofuel-fed/biofuel cells that directly/indirectly extract energy from biomass resources, and discuss the challenges and perspectives in this developing field.

Critical role of the sorting polymer in carbon nanotube-based minority carrier devices

DOE PAGES

Mallajosyula, Arun T.; Nie, Wanyi; Gupta, Gautam; ...

2016-11-27

A prerequisite for carbon nanotube-based optoelectronic devices is the ability to sort them into a pure semiconductor phase. One of the most common sorting routes is enabled through using specific wrapping polymers. Here we show that subtle changes in the polymer structure can have a dramatic influence on the figures of merit of a carbon nanotube-based photovoltaic device. By comparing two commonly used polyfluorenes (PFO and PFO-BPy) for wrapping (7,5) and (6,5) chirality SWCNTs, we demonstrate that they have contrasting effects on the device efficiency. We attribute this to the differences in their ability to efficiently transfer charge. Although PFOmore » may act as an efficient interfacial layer at the anode, PFO-BPy, having the additional pyridine side groups, forms a high resistance layer degrading the device efficiency. By comparing PFO|C 60 and C 60-only devices, we found that presence of a PFO layer at low optical densities resulted in the increase of all three solar cell parameters, giving nearly an order of magnitude higher efficiency over that of C 60-only devices. In addition, with a relatively higher contribution to photocurrent from the PFO-C 60 interface, an open circuit voltage of 0.55 V was obtained for PFO-(7,5)-C 60 devices. On the other hand, PFO-BPy does not affect the open circuit voltage but drastically reduces the short circuit current density. Lastly, these results indicate that the charge transport properties and energy levels of the sorting polymers have to be taken into account to fully understand their effect on carbon nanotube-based solar cells.« less

Carbon nanotube oscillator surface profiling device and method of use

DOEpatents

Popescu, Adrian [Tampa, FL; Woods, Lilia M [Tampa, FL; Bondarev, Igor V [Fuquay Varina, NC

2011-11-15

The proposed device is based on a carbon nanotube oscillator consisting of a finite length outer stationary nanotube and a finite length inner oscillating nanotube. Its main function is to measure changes in the characteristics of the motion of the carbon nanotube oscillating near a sample surface, and profile the roughness of this surface. The device operates in a non-contact mode, thus it can be virtually non-wear and non-fatigued system. It is an alternative to the existing atomic force microscope (AFM) tips used to scan surfaces to determine their roughness.

Broadband photodetector based on carbon nanotube thin film/single layer graphene Schottky junction

NASA Astrophysics Data System (ADS)

Zhang, Teng-Fei; Li, Zhi-Peng; Wang, Jiu-Zhen; Kong, Wei-Yu; Wu, Guo-An; Zheng, Yu-Zhen; Zhao, Yuan-Wei; Yao, En-Xu; Zhuang, Nai-Xi; Luo, Lin-Bao

2016-12-01

In this study, we present a broadband nano-photodetector based on single-layer graphene (SLG)-carbon nanotube thin film (CNTF) Schottky junction. It was found that the as-fabricated device exhibited obvious sensitivity to a wide range of illumination, with peak sensitivity at 600 and 920 nm. In addition, the SLG-CNTF device had a fast response speed (τr = 68 μs, τf = 78 μs) and good reproducibility in a wide range of switching frequencies (50-5400 Hz). The on-off ratio, responsivity, and detectivity of the device were estimated to be 1 × 102, 209 mAW-1 and 4.87 × 1010 cm Hz1/2 W-1, respectively. What is more, other device parameters including linear performance θ and linear dynamic range (LDR) were calculated to be 0.99 and 58.8 dB, respectively, which were relatively better than other carbon nanotube based devices. The totality of the above study signifies that the present SLG-CNTF Schottky junction broadband nano-photodetector may have promising application in future nano-optoelectronic devices and systems.

Broadband photodetector based on carbon nanotube thin film/single layer graphene Schottky junction

PubMed Central

Zhang, Teng-Fei; Li, Zhi-Peng; Wang, Jiu-Zhen; Kong, Wei-Yu; Wu, Guo-An; Zheng, Yu-Zhen; Zhao, Yuan-Wei; Yao, En-Xu; Zhuang, Nai-Xi; Luo, Lin-Bao

2016-01-01

In this study, we present a broadband nano-photodetector based on single-layer graphene (SLG)-carbon nanotube thin film (CNTF) Schottky junction. It was found that the as-fabricated device exhibited obvious sensitivity to a wide range of illumination, with peak sensitivity at 600 and 920 nm. In addition, the SLG-CNTF device had a fast response speed (τr = 68 μs, τf = 78 μs) and good reproducibility in a wide range of switching frequencies (50–5400 Hz). The on-off ratio, responsivity, and detectivity of the device were estimated to be 1 × 102, 209 mAW−1 and 4.87 × 1010 cm Hz1/2 W−1, respectively. What is more, other device parameters including linear performance θ and linear dynamic range (LDR) were calculated to be 0.99 and 58.8 dB, respectively, which were relatively better than other carbon nanotube based devices. The totality of the above study signifies that the present SLG-CNTF Schottky junction broadband nano-photodetector may have promising application in future nano-optoelectronic devices and systems. PMID:27929053

Hot spot dynamics in carbon nanotube array devices.

PubMed

Engel, Michael; Steiner, Mathias; Seo, Jung-Woo T; Hersam, Mark C; Avouris, Phaedon

2015-03-11

We report on the dynamics of spatial temperature distributions in aligned semiconducting carbon nanotube array devices with submicrometer channel lengths. By using high-resolution optical microscopy in combination with electrical transport measurements, we observe under steady state bias conditions the emergence of time-variable, local temperature maxima with dimensions below 300 nm, and temperatures above 400 K. On the basis of time domain cross-correlation analysis, we investigate how the intensity fluctuations of the thermal radiation patterns are correlated with the overall device current. The analysis reveals the interdependence of electrical current fluctuations and time-variable hot spot formation that limits the overall device performance and, ultimately, may cause device degradation. The findings have implications for the future development of carbon nanotube-based technologies.

Highly sensitive humidity sensing properties of carbon quantum dots films

DOE Office of Scientific and Technical Information (OSTI.GOV)

Zhang, Xing; Ming, Hai; Liu, Ruihua

2013-02-15

Graphical abstract: Display Omitted Highlights: ► A humidity sensing device was fabricated based on carbon quantum dots (CQDs) films. ► The conductivity of the CQDs films shows a linear and rapid response to atmosphere humidity. ► The humidity sensing property was due to the hydrogen bonds between the functional groups on CQDs. -- Abstract: We reported the fabrication of a humidity sensing device based on carbon quantum dots (CQDs) film. The conductivity of the CQDs film has a linear and rapid response to relative humidity, providing the opportunity for the fabrication of humidity sensing devices. The mechanism of our humiditymore » sensor was proposed to be the formation of hydrogen bonds between carbon quantum dots and water molecules in the humidity environment, which significantly promote the electrons migration. In a control experiment, this hypothesis was confirmed by comparing the humidity sensitivity of candle soot (i.e. carbon nanoparticles) with and without oxygen containing groups on the surfaces.« less

Ultrathin Graphene Membranes as Flexible Electrodes for Electrochemical Double Layer Capacitors

NASA Astrophysics Data System (ADS)

Talapatra, Saikat; Kar, Swastik; Shah, Rakesh; Ghosh, Sujoy; An, Xiaohong; Simmons, Trevor; Washington, Morris; Nayak, Saroj

2010-03-01

We will present the results of our investigations of electrochemical double layer capacitors (EDLCs) or supercapacitors (SC) fabricated using graphene based ultra thin membranes. These EDLC's show far superior performance compared to other carbon nanomaterials based EDLC's devices. We found that the graphene based devices possess specific capacitance values as high as 120 F/g, with impressive power densities (˜105 kW/kg) and energy densities (˜9.2 Wh/kg). Further, these devices indicated rapid charge transfer response even without the use of any binders or specially prepared current collectors. Our ultracapacitors reflect a significant improvement over previously reported graphene-based ultracapacitors and are substantially better than those obtained with carbon nanotubes.

Elaboration of a microstructured inkjet-printed carbon electrochemical capacitor

NASA Astrophysics Data System (ADS)

Pech, David; Brunet, Magali; Taberna, Pierre-Louis; Simon, Patrice; Fabre, Norbert; Mesnilgrente, Fabien; Conédéra, Véronique; Durou, Hugo

Carbon-based micro-supercapacitors dedicated to energy storage in self-powered modules were fabricated with inkjet printing technology on silicon substrate. An ink was first prepared by mixing an activated carbon powder with a PTFE polymer binder in ethylene glycol stabilized with a surfactant then deposited by inkjet on patterned gold current collectors with the substrate heated at 140 °C in order to assure a good homogeneity. Electrochemical micro-capacitors with electrodes in an interdigital configuration were fabricated, and characterized using electrochemical techniques in 1 M Et 4NBF 4 propylene carbonate electrolyte. These micro-devices show an excellent capacitive behavior over a wide potential range of 2.5 V for a cell capacitance of 2.1 mF cm -2. The newly developed technology will allow the integration of the storage device as close as possible to the MEMS-based energy harvesting device, minimizing power losses through connections.

High Per formance and Flexible Supercapacitors based on Carbonized Bamboo Fibers for Wide Temperature Applications

PubMed Central

Zequine, Camila; Ranaweera, C. K.; Wang, Z.; Singh, Sweta; Tripathi, Prashant; Srivastava, O. N.; Gupta, Bipin Kumar; Ramasamy, K.; Kahol, P. K.; Dvornic, P. R.; Gupta, Ram K.

2016-01-01

High performance carbonized bamboo fibers were synthesized for a wide range of temperature dependent energy storage applications. The structural and electrochemical properties of the carbonized bamboo fibers were studied for flexible supercapacitor applications. The galvanostatic charge-discharge studies on carbonized fibers exhibited specific capacity of ~510F/g at 0.4 A/g with energy density of 54 Wh/kg. Interestingly, the carbonized bamboo fibers displayed excellent charge storage stability without any appreciable degradation in charge storage capacity over 5,000 charge-discharge cycles. The symmetrical supercapacitor device fabricated using these carbonized bamboo fibers exhibited an areal capacitance of ~1.55 F/cm2 at room temperature. In addition to high charge storage capacity and cyclic stability, the device showed excellent flexibility without any degradation to charge storage capacity on bending the electrode. The performance of the supercapacitor device exhibited ~65% improvement at 70 °C compare to that at 10 °C. Our studies suggest that carbonized bamboo fibers are promising candidates for stable, high performance and flexible supercapacitor devices. PMID:27546225

High Per formance and Flexible Supercapacitors based on Carbonized Bamboo Fibers for Wide Temperature Applications.

PubMed

Zequine, Camila; Ranaweera, C K; Wang, Z; Singh, Sweta; Tripathi, Prashant; Srivastava, O N; Gupta, Bipin Kumar; Ramasamy, K; Kahol, P K; Dvornic, P R; Gupta, Ram K

2016-08-22

High performance carbonized bamboo fibers were synthesized for a wide range of temperature dependent energy storage applications. The structural and electrochemical properties of the carbonized bamboo fibers were studied for flexible supercapacitor applications. The galvanostatic charge-discharge studies on carbonized fibers exhibited specific capacity of ~510F/g at 0.4 A/g with energy density of 54 Wh/kg. Interestingly, the carbonized bamboo fibers displayed excellent charge storage stability without any appreciable degradation in charge storage capacity over 5,000 charge-discharge cycles. The symmetrical supercapacitor device fabricated using these carbonized bamboo fibers exhibited an areal capacitance of ~1.55 F/cm(2) at room temperature. In addition to high charge storage capacity and cyclic stability, the device showed excellent flexibility without any degradation to charge storage capacity on bending the electrode. The performance of the supercapacitor device exhibited ~65% improvement at 70 °C compare to that at 10 °C. Our studies suggest that carbonized bamboo fibers are promising candidates for stable, high performance and flexible supercapacitor devices.

High Per formance and Flexible Supercapacitors based on Carbonized Bamboo Fibers for Wide Temperature Applications

NASA Astrophysics Data System (ADS)

Zequine, Camila; Ranaweera, C. K.; Wang, Z.; Singh, Sweta; Tripathi, Prashant; Srivastava, O. N.; Gupta, Bipin Kumar; Ramasamy, K.; Kahol, P. K.; Dvornic, P. R.; Gupta, Ram K.

2016-08-01

High performance carbonized bamboo fibers were synthesized for a wide range of temperature dependent energy storage applications. The structural and electrochemical properties of the carbonized bamboo fibers were studied for flexible supercapacitor applications. The galvanostatic charge-discharge studies on carbonized fibers exhibited specific capacity of ~510F/g at 0.4 A/g with energy density of 54 Wh/kg. Interestingly, the carbonized bamboo fibers displayed excellent charge storage stability without any appreciable degradation in charge storage capacity over 5,000 charge-discharge cycles. The symmetrical supercapacitor device fabricated using these carbonized bamboo fibers exhibited an areal capacitance of ~1.55 F/cm2 at room temperature. In addition to high charge storage capacity and cyclic stability, the device showed excellent flexibility without any degradation to charge storage capacity on bending the electrode. The performance of the supercapacitor device exhibited ~65% improvement at 70 °C compare to that at 10 °C. Our studies suggest that carbonized bamboo fibers are promising candidates for stable, high performance and flexible supercapacitor devices.

Field Emission Characteristics of Carbon Nanotubes and Their Applications in Sensors and Devices

NASA Astrophysics Data System (ADS)

Vaseashta, Ashok

2003-03-01

FIELD EMISSION CHARACTERISTICS OF CARBON NANOTUBES AND THEIR APPLICATIONS IN SENSORS AND DEVICES A. Vaseashta, C. Shaffer, M. Collins, A. Mwuara Dept of Physics, Marshall University, Huntington, WV V. Pokropivny Institute for Materials Sciences of NASU, Kiev, Ukraine. D. Dimova-Malinovska Bulgarian Academy of Sciences, Sofia, Bulgaria. The dimensionality of a system has profound influence on its physical behavior. With advances in technology over the past few decades, it has become possible to fabricate and study reduced-dimensional systems, such as carbon nanotubes (CNTs). Carbon nanotubes are especially promising candidate for cold cathode field emitter because of their electrical properties, high aspect ratio, and small radius of curvature at the tips. Electron emission from the carbon nanotubes was investigated. Based upon the field emission investigation of carbon nanotubes, several prototype devices have been suggested that operate with low swing voltages with sufficient high current densities. Characteristics that allow improved current stability and long lifetime operation for electrical and opto-electronics devices are presented. The aim of this brief overview is to illustrate the useful characteristics of carbon nanotubes and its possible application.

Carbon nanotube/polymer composite coated tapered fiber for four wave mixing based wavelength conversion.

PubMed

Xu, Bo; Omura, Mika; Takiguchi, Masato; Martinez, Amos; Ishigure, Takaaki; Yamashita, Shinji; Kuga, Takahiro

2013-02-11

In this paper, we demonstrate a nonlinear optical device based on a fiber taper coated with a carbon nanotube (CNT)/polymer composite. Using this device, four wave mixing (FWM) based wavelength conversion of 10 Gb/s Non-return-to-zero signal is achieved. In addition, we investigate wavelength tuning, two photon absorption and estimate the effective nonlinear coefficient of the CNTs embedded in the tapered fiber to be 1816.8 W(-1)km(-1).

Ultrafast graphene and carbon nanotube film patterning by picosecond laser pulses

NASA Astrophysics Data System (ADS)

Bobrinetskiy, Ivan I.; Emelianov, Alexey V.; Otero, Nerea; Romero, Pablo M.

2016-03-01

Carbon nanomaterials is among the most promising technologies for advanced electronic applications, due to their extraordinary chemical and physical properties. Nonetheless, after more than two decades of intensive research, the application of carbon-based nanostructures in real electronic and optoelectronic devices is still a big challenge due to lack of scalable integration in microelectronic manufacturing. Laser processing is an attractive tool for graphene device manufacturing, providing a large variety of processes through direct and indirect interaction of laser beams with graphene lattice: functionalization, oxidation, reduction, etching and ablation, growth, etc. with resolution down to the nanoscale. Focused laser radiation allows freeform processing, enabling fully mask-less fabrication of devices from graphene and carbon nanotube films. This concept is attractive to reduce costs, improve flexibility, and reduce alignment operations, by producing fully functional devices in single direct-write operations. In this paper, a picosecond laser with a wavelength of 515 nm and pulse width of 30 ps is used to pattern carbon nanostructures in two ways: ablation and chemical functionalization. The light absorption leads to thermal ablation of graphene and carbon nanotube film under the fluence 60-90 J/cm2 with scanning speed up to 2 m/s. Just under the ablation energy, the two-photon absorption leads to add functional groups to the carbon lattice which change the optical properties of graphene. This paper shows the results of controlled modification of geometrical configuration and the physical and chemical properties of carbon based nanostructures, by laser direct writing.

Room-temperature low-voltage electroluminescence in amorphous carbon nitride thin films

NASA Astrophysics Data System (ADS)

Reyes, R.; Legnani, C.; Ribeiro Pinto, P. M.; Cremona, M.; de Araújo, P. J. G.; Achete, C. A.

2003-06-01

White-blue electroluminescent emission with a voltage bias less than 10 V was achieved in rf sputter-deposited amorphous carbon nitride (a-CN) and amorphous silicon carbon nitride (a-SiCN) thin-film-based devices. The heterojunction structures of these devices consist of: Indium tin oxide (ITO), used as a transparent anode; amorphous carbon film as an emission layer, and aluminum as a cathode. The thickness of the carbon films was about 250 Å. In all of the produced diodes, a stable visible emission peaked around 475 nm is observed at room temperature and the emission intensity increases with the current density. For an applied voltage of 14 V, the luminance was about 3 mCd/m2. The electroluminescent properties of the two devices are discussed and compared.

Hybrid Quantum Device with Nitrogen-Vacancy Centers in Diamond Coupled to Carbon Nanotubes

NASA Astrophysics Data System (ADS)

Li, Peng-Bo; Xiang, Ze-Liang; Rabl, Peter; Nori, Franco

2016-07-01

We show that nitrogen-vacancy (NV) centers in diamond interfaced with a suspended carbon nanotube carrying a dc current can facilitate a spin-nanomechanical hybrid device. We demonstrate that strong magnetomechanical interactions between a single NV spin and the vibrational mode of the suspended nanotube can be engineered and dynamically tuned by external control over the system parameters. This spin-nanomechanical setup with strong, intrinsic, and tunable magnetomechanical couplings allows for the construction of hybrid quantum devices with NV centers and carbon-based nanostructures, as well as phonon-mediated quantum information processing with spin qubits.

Functional materials based on carbon nanotubes: Carbon nanotube actuators and noncovalent carbon nanotube modification

NASA Astrophysics Data System (ADS)

Fifield, Leonard S.

Carbon nanotubes have attractive inherent properties that encourage the development of new functional materials and devices based on them. The use of single wall carbon nanotubes as electromechanical actuators takes advantage of the high mechanical strength, surface area and electrical conductivity intrinsic to these molecules. The work presented here investigates the mechanisms that have been discovered for actuation of carbon nanotube paper: electrostatic, quantum chemical charge injection, pneumatic and viscoelastic. A home-built apparatus for the measurement of actuation strain is developed and utilized in the investigation. An optical fiber switch, the first demonstrated macro-scale device based on the actuation of carbon nanotubes, is described and its performance evaluated. Also presented here is a new general process designed to modify the surface of carbon nanotubes in a non-covalent, non-destructive way. This method can be used to impart new functionalities to carbon nanotube samples for a variety of applications including sensing, solar energy conversion and chemical separation. The process described involves the achievement of large degrees of graphitic surface coverage with polycyclic aromatic hydrocarbons through the use of supercritical fluids. These molecules are bifunctional agents that anchor a desired chemical group to the aromatic surface of the carbon nanotubes without adversely disrupting the conjugated backbone that gives rise the attractive electronic and physical properties of the nanotubes. Both the nanotube functionalization work and the actuator work presented here emphasize how an understanding and control of nanoscale structure and phenomena can be of vital importance in achieving desired performance for active materials. Opportunities for new devices with improved function over current state-of-the-art can be envisioned and anticipated based on this understanding and control.

Photovoltaic devices based on high density boron-doped single-walled carbon nanotube/n-Si heterojunctions

DOE Office of Scientific and Technical Information (OSTI.GOV)

Saini, Viney; Li, Zhongrui; Bourdo, Shawn

2011-01-13

A simple and easily processible photovoltaic device has been developed based on borondoped single-walled carbon nanotubes (B-SWNTs) and n-type silicon (n-Si) heterojunctions. The single-walled carbon nanotubes (SWNTs) were substitutionally doped with boron atoms by thermal annealing, in the presence of B 2O 3. The samples used for these studies were characterized by Raman spectroscopy, thermal gravimetric analysis (TGA), transmission electron microscopy (TEM), and x-ray photoelectron spectroscopy (XPS). The fully functional solar cell devices were fabricated by airbrush deposition that generated uniform B-SWNT films on top of the n-Si substrates. The carbon nanotube films acted as exciton-generation sites, charge collection andmore » transportation, while the heterojunctions formed between B-SWNTs and n-Si acted as charge dissociation centers. The current-voltage characteristics in the absence of light and under illumination, as well as optical transmittance spectrum are reported here. It should be noted that the device fabrication process can be made amenable to scalability by depositing direct and uniform films using airbrushing, inkjet printing, or spin-coating techniques.« less

Self-aligned gated field emission devices using single carbon nanofiber cathodes

NASA Astrophysics Data System (ADS)

Guillorn, M. A.; Melechko, A. V.; Merkulov, V. I.; Hensley, D. K.; Simpson, M. L.; Lowndes, D. H.

2002-11-01

We report on the fabrication and operation of integrated gated field emission devices using single vertically aligned carbon nanofiber (VACNF) cathodes where the gate aperture has been formed using a self-aligned technique based on chemical mechanical polishing. We find that this method for producing gated cathode devices easily achieves structures with gate apertures on the order of 2 mum that show good concentric alignment to the VACNF emitter. The operation of these devices was explored and field emission characteristics that fit well to the Fowler-Nordheim model of emission was demonstrated.

Carbon Nanotubes and Graphene for Flexible Electrochemical Energy Storage: from Materials to Devices.

PubMed

Wen, Lei; Li, Feng; Cheng, Hui-Ming

2016-06-01

Flexible electrochemical energy storage (FEES) devices have received great attention as a promising power source for the emerging field of flexible and wearable electronic devices. Carbon nanotubes (CNTs) and graphene have many excellent properties that make them ideally suited for use in FEES devices. A brief definition of FEES devices is provided, followed by a detailed overview of various structural models for achieving different FEES devices. The latest research developments on the use of CNTs and graphene in FEES devices are summarized. Finally, future prospects and important research directions in the areas of CNT- and graphene-based flexible electrode synthesis and device integration are discussed. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Focused-electron-beam-induced processing (FEBIP) for emerging applications in carbon nanoelectronics

NASA Astrophysics Data System (ADS)

Fedorov, Andrei G.; Kim, Songkil; Henry, Mathias; Kulkarni, Dhaval; Tsukruk, Vladimir V.

2014-12-01

Focused-electron-beam-induced processing (FEBIP), a resist-free additive nanomanufacturing technique, is an actively researched method for "direct-write" processing of a wide range of structural and functional nanomaterials, with high degree of spatial and time-domain control. This article attempts to critically assess the FEBIP capabilities and unique value proposition in the context of processing of electronics materials, with a particular emphasis on emerging carbon (i.e., based on graphene and carbon nanotubes) devices and interconnect structures. One of the major hurdles in advancing the carbon-based electronic materials and device fabrication is a disjoint nature of various processing steps involved in making a functional device from the precursor graphene/CNT materials. Not only this multi-step sequence severely limits the throughput and increases the cost, but also dramatically reduces the processing reproducibility and negatively impacts the quality because of possible between-the-step contamination, especially for impurity-susceptible materials such as graphene. The FEBIP provides a unique opportunity to address many challenges of carbon nanoelectronics, especially when it is employed as part of an integrated processing environment based on multiple "beams" of energetic particles, including electrons, photons, and molecules. This avenue is promising from the applications' prospective, as such a multi-functional (electron/photon/molecule beam) enables one to define shapes (patterning), form structures (deposition/etching), and modify (cleaning/doping/annealing) properties with locally resolved control on nanoscale using the same tool without ever changing the processing environment. It thus will have a direct positive impact on enhancing functionality, improving quality and reducing fabrication costs for electronic devices, based on both conventional CMOS and emerging carbon (CNT/graphene) materials.

An overview of carbon materials for flexible electrochemical capacitors.

PubMed

He, Yongmin; Chen, Wanjun; Gao, Caitian; Zhou, Jinyuan; Li, Xiaodong; Xie, Erqing

2013-10-07

Under the background of the quick development of lightweight, flexible, and wearable electronic devices in our society, a flexible and highly efficient energy management strategy is needed for their counterpart energy-storage systems. Among them, flexible electrochemical capacitors (ECs) have been considered as one of the most promising candidates because of their significant advantages in power and energy densities, and unique properties of being flexible, lightweight, low-cost, and environmentally friendly compared with current energy storage devices. In a common EC, carbon materials play an irreplaceable and principal role in its energy-storage performance. Up till now, most progress towards flexible ECs technologies has mostly benefited from the continuous development of carbon materials. As a result, in view of the dual remarkable highlights of ECs and carbon materials, a summary of recent research progress on carbon-based flexible EC electrode materials is presented in this review, including carbon fiber (CF, consisting of carbon microfiber-CMF and carbon nanofiber-CNF) networks, carbon nanotube (CNT) and graphene coatings, CNT and/or graphene papers (or films), and freestanding three-dimensional (3D) flexible carbon-based macroscopic architectures. Furthermore, some promising carbon materials for great potential applications in flexible ECs are introduced. Finally, the trends and challenges in the development of carbon-based electrode materials for flexible ECs and their smart applications are analyzed.

Three-dimensional carbon architectures for electrochemical capacitors.

PubMed

Song, Yu; Liu, Tianyu; Qian, Fang; Zhu, Cheng; Yao, Bin; Duoss, Eric; Spadaccini, Christopher; Worsley, Marcus; Li, Yat

2018-01-01

Three-dimensional (3D) carbon-based materials are emerging as promising electrode candidates for energy storage devices. In comparison to the 1D and 2D structures, 3D morphology offers new opportunities in rational design and synthesis of novel architectures tailor-made for promoting electrochemical performance. The capability of building hierarchical porous structures with 3D configuration can significantly advance the performance of energy storage devices by simultaneously enhancing the ion-accessible surface area and ion diffusion. This feature article presents an overview of recent progress in design, synthesis and implementation of 3D carbon-based materials as electrodes for electrochemical capacitors. Synthesis methodologies of four types of 3D carbon-based electrodes: 3D exfoliated carbon structures, 3D graphene scaffolds, 3D hierarchical porous carbon foams, as well as 3D architectures with periodic pores derived from direct ink writing, are thoroughly discussed and highlighted with selected experimental works. Finally, key opportunities and challenges in which different 3D carbons can significantly impact the energy storage and conversion communities will be provided. Copyright © 2017 Elsevier Inc. All rights reserved.

Fabrication of a novel carbon nanotube & graphene based device for gas detection

NASA Astrophysics Data System (ADS)

Khosravi, Yusef; Abdi, Yaser; Arzi, Ezatollah

2018-06-01

We present a novel, simple method for gas detection using a nano-device fabricated on a silicon substrate. The proposed method is based on changing the density of state (DOS) of a graphene sheet during the gas absorption. Fabrication of the carbon nanotube (CNT) and graphene based device for gas detection includes silicon micro machining and the growth of vertically aligned CNTs. Field emission between the as-grown CNTs and the graphene sheet which is placed on top of the CNTs is measured at a liquid nitrogen temperature to obtain the DOS of the structure in different gas environments. The measured local DOS of the structure using the fabricated device showed that each gas had its own signatory spectrum. We believe that this method will open up a new and simple way of fabricating a portable gas spectroscope.

Is hexagonal boron nitride always good as a substrate for carbon nanotube-based devices?

PubMed

Kang, Seoung-Hun; Kim, Gunn; Kwon, Young-Kyun

2015-02-21

Hexagonal boron nitride sheets have been noted especially for their enhanced properties as substrates for sp(2) carbon-based nanodevices. To evaluate whether such enhanced properties would be retained under various realistic conditions, we investigate the structural and electronic properties of semiconducting carbon nanotubes on perfect and defective hexagonal boron nitride sheets under an external electric field as well as with a metal impurity, using density functional theory. We verify that the use of a perfect hexagonal boron nitride sheet as a substrate indeed improves the device performances of carbon nanotubes, compared with the use of conventional substrates such as SiO2. We further show that even the hexagonal boron nitride with some defects can show better performance as a substrate. Our calculations, on the other hand, also suggest that some defective boron nitride layers with a monovacancy and a nickel impurity could bring about poor device behavior since the imperfections impair electrical conductivity due to residual scattering under an applied electric field.

Integrated carbon fiber electrodes within hollow polymer microneedles for transdermal electrochemical sensing

PubMed Central

Miller, Philip R.; Gittard, Shaun D.; Edwards, Thayne L.; Lopez, DeAnna M.; Xiao, Xiaoyin; Wheeler, David R.; Monteiro-Riviere, Nancy A.; Brozik, Susan M.; Polsky, Ronen; Narayan, Roger J.

2011-01-01

In this study, carbon fiber electrodes were incorporated within a hollow microneedle array, which was fabricated using a digital micromirror device-based stereolithography instrument. Cell proliferation on the acrylate-based polymer used in microneedle fabrication was examined with human dermal fibroblasts and neonatal human epidermal keratinocytes. Studies involving full-thickness cadaveric porcine skin and trypan blue dye demonstrated that the hollow microneedles remained intact after puncturing the outermost layer of cadaveric porcine skin. The carbon fibers underwent chemical modification in order to enable detection of hydrogen peroxide and ascorbic acid; electrochemical measurements were demonstrated using integrated electrode-hollow microneedle devices. PMID:21522504

X-ray irradiation-induced structural changes on Single Wall Carbon Nanotubes

NASA Astrophysics Data System (ADS)

Bardi, N.; Jurewicz, I.; King, A. K.; Alkhorayef, M. A.; Bradley, D.; Dalton, A. B.

2017-11-01

Dosimetry devices based on Carbon Nanotubes are a promising new technology. In particular using devices based on single wall Carbon Nanotubes may offer a tissue equivalent response with the possibility for device miniaturisation, high scale manufacturing and low cost. An important precursor to device fabrication requires a quantitative study of the effects of X-ray radiation on the physical and chemical properties of the individual nanotubes. In this study, we concentrate on the effects of relatively low doses, 20 cGy and 45 cGy , respectively. We use a range of characterization techniques including scanning electron microscopy, Raman spectroscopy and X-ray photoelectron spectroscopy to quantify the effects of the radiation dose on inherent properties of the nanotubes. Specifically we find that the radiation exposure results in a reduction in the sp2 nature of the nanotube bond structure. Moreover, our analysis indicates that the exposure results in nanotubes that have an increased defect density which ultimately effects the electrical properties of the nanotubes.

Direct measurement of chiral structure and transport in single- and multi-walled carbon nanotubes

NASA Astrophysics Data System (ADS)

Cui, Taoran; Lin, Letian; Qin, Lu-Chang; Washburn, Sean

2016-11-01

Electrical devices based on suspended multi-wall carbon nanotubes were constructed and studied. The chiral structure of each shell in a particular nanotube was determined using nanobeam electron diffraction in a transmission electron microscope. The transport properties of the carbon nanotube were also measured. The nanotube device length was short enough that the transport was nearly ballistic, and multiple subbands contributed to the conductance. Thermal excitation of carriers significantly affected nanotube resistance at room temperature.

Flexible and Robust Thermoelectric Generators Based on All-Carbon Nanotube Yarn without Metal Electrodes.

PubMed

Choi, Jaeyoo; Jung, Yeonsu; Yang, Seung Jae; Oh, Jun Young; Oh, Jinwoo; Jo, Kiyoung; Son, Jeong Gon; Moon, Seung Eon; Park, Chong Rae; Kim, Heesuk

2017-08-22

As practical interest in flexible/or wearable power-conversion devices increases, the demand for high-performance alternatives to thermoelectric (TE) generators based on brittle inorganic materials is growing. Herein, we propose a flexible and ultralight TE generator (TEG) based on carbon nanotube yarn (CNTY) with excellent TE performance. The as-prepared CNTY shows a superior electrical conductivity of 3147 S/cm due to increased longitudinal carrier mobility derived from a highly aligned structure. Our TEG is innovative in that the CNTY acts as multifunctions in the same device. The CNTY is alternatively doped into n- and p-types using polyethylenimine and FeCl 3 , respectively. The highly conductive CNTY between the doped regions is used as electrodes to minimize the circuit resistance, thereby forming an all-carbon TEG without additional metal deposition. A flexible TEG based on 60 pairs of n- and p-doped CNTY shows the maximum power density of 10.85 and 697 μW/g at temperature differences of 5 and 40 K, respectively, which are the highest values among reported TEGs based on flexible materials. We believe that the strategy proposed here to improve the power density of flexible TEG by introducing highly aligned CNTY and designing a device without metal electrodes shows great potential for the flexible/or wearable power-conversion devices.

Carbon nanotube based hybrid nanostructures: Synthesis and applications

NASA Astrophysics Data System (ADS)

Ou, Fung Suong

Hybrid nanostructures are fascinating materials for their promising applications in future nanoelectronics, electrical interconnects and energy storage devices. Practical ways of connecting individual carbon nanotubes to metal contacts for their use as interconnects and in electronic devices have been challenging. In this thesis, carbon nanotube based hybrids that combine the best properties of carbon nanotubes and metal nanowires have been fabricated. The electrical properties and Raman spectra of the hybrid nanowires are also studied. This thesis will focus on our recent results in the development of carbon nanotube hybrids for various applications. Various hybrid structures of multiwalled carbon nanotubes and metal nanowires can be fabricated using a combination of electrodeposition and chemical vapor deposition techniques. Controlled fabrication of multi-segmented structures will be studied. Several novel applications of these structures, for example, as electrodes in ultra-high power supercapacitors, multi-functional smart materials are also studied. The thesis will also highlight the development of carbon nanotube hybrids based smart materials. Hybrid nanowires with hydrophobic carbon nanotube tails and hydrophilic metal nanowire heads, allows for the assembly of spheres in solution. The design and manipulation of these carbon nanotube hybrids based smart structures for various novel applications will be discussed. Such new class of carbon nanotube hybrids surfactants are likely to lead as new tools in various fields such as microfluidics or water purification. In addition, we will also look at other variations of hybrid nanostructures fabricated from our method.

Thermally Conductive Metal-Tube/Carbon-Composite Joints

NASA Technical Reports Server (NTRS)

Copeland, Robert J.

2004-01-01

An improved method of fabricating joints between metal and carbon-fiber-based composite materials in lightweight radiators and heat sinks has been devised. Carbon-fiber-based composite materials have been used in such heat-transfer devices because they offer a combination of high thermal conductivity and low mass density. Metal tubes are typically used to carry heat-transfer fluids to and from such heat-transfer devices. The present fabrication method helps to ensure that the joints between the metal tubes and the composite-material parts in such heat-transfer devices have both (1) the relatively high thermal conductances needed for efficient transfer of heat and (2) the flexibility needed to accommodate differences among thermal expansions of dissimilar materials in operation over wide temperature ranges. Techniques used previously to join metal tubes with carbon-fiber-based composite parts have included press fitting and bonding with epoxy. Both of these prior techniques have been found to yield joints characterized by relatively high thermal resistances. The present method involves the use of a solder (63 percent Sn, 37 percent Pb) to form a highly thermally conductive joint between a metal tube and a carbon-fiber-based composite structure. Ordinarily, the large differences among the coefficients of thermal expansion of the metal tube, solder, and carbon-fiber-based composite would cause the solder to pull away from the composite upon post-fabrication cooldown from the molten state. In the present method, the structure of the solder is modified (see figure) to enable it to deform readily to accommodate the differential thermal expansion.

Nitrogen doped carbon derived from polyimide/multiwall carbon nanotube composites for high performance flexible all-solid-state supercapacitors

NASA Astrophysics Data System (ADS)

Kim, Dae Kyom; Kim, Nam Dong; Park, Seung-Keun; Seong, Kwang-dong; Hwang, Minsik; You, Nam-Ho; Piao, Yuanzhe

2018-03-01

Flexible all-solid-state supercapacitors are desirable as potential energy storage systems for wearable technologies. Herein, we synthesize aminophenyl multiwall carbon nanotube (AP-MWCNT) grafted polyimide precursor by in situ polymerization method as a nitrogen-doped carbon precursor. Flexible supercapacitor electrodes are fabricated via a coating of carbon precursor on carbon cloth surface and carbonization at high temperature directly. The as-obtained electrodes, which can be directly used without any binders or additives, can deliver a high specific capacitance of 333.4 F g-1 at 1 A g-1 (based on active material mass) and excellent cycle stability with 103% capacitance retention after 10,000 cycles in a three-electrode system. The flexible all-solid-state supercapacitor device exhibits a high volumetric capacitance of 3.88 F cm-3 at a current density of 0.02 mA cm-3. And also the device can deliver a maximum volumetric energy density of 0.50 mWh cm-3 and presents good cycling stability with 85.3% capacitance retention after 10,000 cycles. This device cell can not only show extraordinary mechanical flexibilities allowing folding, twisting, and rolling but also demonstrate remarkable stable electrochemical performances under their forms. This work provides a novel approach to obtain carbon textile-based flexible supercapacitors with high electrochemical performance and mechanical flexibility.

Graphene-Based Systems for Energy Storage

NASA Technical Reports Server (NTRS)

Calle, Carlos I.; Mackey, Paul J.; Johansen, Michael R.; Phillips, James, III; Hogue, Michael; Kaner, Richard B.; El-Kady, Maher

2016-01-01

Development of graphene-based energy storage devices based on the Laser Scribe system developed by the University of California Los Angeles. These devices These graphene-based devices store charge on graphene sheets and take advantage of the large accessible surface area of graphene (2,600 m2g) to increase the electrical energy that can be stored. The proposed devices should have the electrical storage capacity of thin-film-ion batteries but with much shorter charge discharge cycle times as well as longer lives The proposed devices will be carbon-based and so will not have the same issues with flammability or toxicity as the standard lithium-based storage cells.

Communication: Photoinduced carbon dioxide binding with surface-functionalized silicon quantum dots.

PubMed

Douglas-Gallardo, Oscar A; Sánchez, Cristián Gabriel; Vöhringer-Martinez, Esteban

2018-04-14

Nowadays, the search for efficient methods able to reduce the high atmospheric carbon dioxide concentration has turned into a very dynamic research area. Several environmental problems have been closely associated with the high atmospheric level of this greenhouse gas. Here, a novel system based on the use of surface-functionalized silicon quantum dots (sf-SiQDs) is theoretically proposed as a versatile device to bind carbon dioxide. Within this approach, carbon dioxide trapping is modulated by a photoinduced charge redistribution between the capping molecule and the silicon quantum dots (SiQDs). The chemical and electronic properties of the proposed SiQDs have been studied with a Density Functional Theory and Density Functional Tight-Binding (DFTB) approach along with a time-dependent model based on the DFTB framework. To the best of our knowledge, this is the first report that proposes and explores the potential application of a versatile and friendly device based on the use of sf-SiQDs for photochemically activated carbon dioxide fixation.

Communication: Photoinduced carbon dioxide binding with surface-functionalized silicon quantum dots

NASA Astrophysics Data System (ADS)

Douglas-Gallardo, Oscar A.; Sánchez, Cristián Gabriel; Vöhringer-Martinez, Esteban

2018-04-01

Nowadays, the search for efficient methods able to reduce the high atmospheric carbon dioxide concentration has turned into a very dynamic research area. Several environmental problems have been closely associated with the high atmospheric level of this greenhouse gas. Here, a novel system based on the use of surface-functionalized silicon quantum dots (sf-SiQDs) is theoretically proposed as a versatile device to bind carbon dioxide. Within this approach, carbon dioxide trapping is modulated by a photoinduced charge redistribution between the capping molecule and the silicon quantum dots (SiQDs). The chemical and electronic properties of the proposed SiQDs have been studied with a Density Functional Theory and Density Functional Tight-Binding (DFTB) approach along with a time-dependent model based on the DFTB framework. To the best of our knowledge, this is the first report that proposes and explores the potential application of a versatile and friendly device based on the use of sf-SiQDs for photochemically activated carbon dioxide fixation.

Calculation of the figure of merit for carbon nanotubes based devices

NASA Astrophysics Data System (ADS)

Vaseashta, Ashok

2004-03-01

The dimensionality of a system has a profound influence on its physical behavior. With advances in technology over the past few decades, it has become possible to fabricate and study reduced-dimensional systems in which electrons are strongly confined in one or more dimensions. In the case of 1-D electron systems, most of the results, such as conductance quantization, have been explained in terms of non-interacting electrons. In contrast to the cases of 2D and 3D systems, the question of what roles electron-electron interactions play in real 1-D systems has been difficult to address, because of the difficulty in obtaining long, relatively disorder free 1-D wires. Since their first discovery and fabrication in 1991, carbon nanotubes (CNTs) have received considerable attention because of the prospect of new fundamental science and many potential applications. Hence, it has been possible to conduct studies of the electrons in 1-D. Carbon nanotubes are of considerable technological importance due to their excellent mechanical, electrical, and chemical characteristics. The potential technological applications include electronics, opto-electronics and biomedical sensors. The applications of carbon nanotubes include quantum wire interconnects, diodes and transistors for computing, capacitors, data storage devices, field emitters, flat panel displays and terahertz oscillators. One of the most remarkable characteristics is the possibility of bandgap engineering by controlling the microstructure. Hence, a pentagon-heptagon defect in the hexagonal network can connect a metallic to a semiconductor nanotube, providing an Angstrom-scale hetero-junction with a device density approximately 10^4 times greater than present day microelectronics. Also, successfully contacted carbon nanotubes have exhibited a large number of useful quantum electronic and low dimensional transport phenomena, such as true quantum wire behaviors, room temperature field effect transistors, room temperature single electron transistors, Luttinger-liquid behavior, the Aharonov Bohm effect, and Fabry-Perot interference effects. Hence it is evident that CNT can be used for a variety of applications. To use CNT based devices, it is critical to know the relative advantage of using CNTs over other known electronic materials. The figure of merit for CNT based devices is not reported so far. It is the objective of this investigation to calculate the figure of merit and present such results. Such calculations will enable researchers to focus their research for specific device designs where CNT based devices show a marked improvement over conventional semiconductor devices.

Designing a Double-Pole Nanoscale Relay Based on a Carbon Nanotube: A Theoretical Study

NASA Astrophysics Data System (ADS)

Mu, Weihua; Ou-Yang, Zhong-can; Dresselhaus, Mildred S.

2017-08-01

We theoretically investigate a novel and powerful double-pole nanoscale relay based on a carbon nanotube, which is one of the nanoelectromechanical switches being able to work under the strong nuclear radiation, and analyze the physical mechanism of the operating stages in the operation, including "pull in," "connection," and "pull back," as well as the key factors influencing the efficiency of the devices. We explicitly provide the analytical expression of the two important operation voltages, Vpull in and Vpull back , therefore clearly showing the dependence of the material properties and geometry of the present devices by the analytical method from basic physics, avoiding complex numerical calculations. Our method is easy to use in preparing the design guide for fabricating the present device and other nanoelectromechanical devices.

Current-induced changes of migration energy barriers in graphene and carbon nanotubes

NASA Astrophysics Data System (ADS)

Obodo, J. T.; Rungger, I.; Sanvito, S.; Schwingenschlögl, U.

2016-05-01

An electron current can move atoms in a nanoscale device with important consequences for the device operation and breakdown. We perform first principles calculations aimed at evaluating the possibility of changing the energy barriers for atom migration in carbon-based systems. In particular, we consider the migration of adatoms and defects in graphene and carbon nanotubes. Although the current-induced forces are large for both the systems, in graphene the force component along the migration path is small and therefore the barrier height is little affected by the current flow. In contrast, the same barrier is significantly reduced in carbon nanotubes as the current increases. Our work also provides a real-system numerical demonstration that current-induced forces within density functional theory are non-conservative.An electron current can move atoms in a nanoscale device with important consequences for the device operation and breakdown. We perform first principles calculations aimed at evaluating the possibility of changing the energy barriers for atom migration in carbon-based systems. In particular, we consider the migration of adatoms and defects in graphene and carbon nanotubes. Although the current-induced forces are large for both the systems, in graphene the force component along the migration path is small and therefore the barrier height is little affected by the current flow. In contrast, the same barrier is significantly reduced in carbon nanotubes as the current increases. Our work also provides a real-system numerical demonstration that current-induced forces within density functional theory are non-conservative. Electronic supplementary information (ESI) available. See DOI: 10.1039/C6NR00534A

Recent Advances in Porous Carbon Materials for Electrochemical Energy Storage.

PubMed

Wang, Libin; Hu, Xianluo

2018-06-18

Climate change and the energy crisis have promoted the rapid development of electrochemical energy-storage devices. Owing to many intriguing physicochemical properties, such as excellent chemical stability, high electronic conductivity, and a large specific surface area, porous carbon materials have always been considering as a promising candidate for electrochemical energy storage. To date, a wide variety of porous carbon materials based upon molecular design, pore control, and compositional tailoring have been proposed for energy-storage applications. This focus review summarizes recent advances in the synthesis of various porous carbon materials from the view of energy storage, particularly in the past three years. Their applications in representative electrochemical energy-storage devices, such as lithium-ion batteries, supercapacitors, and lithium-ion hybrid capacitors, are discussed in this review, with a look forward to offer some inspiration and guidelines for the exploitation of advanced carbon-based energy-storage materials. © 2018 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

Polymer-based materials to be used as the active element in microsensors: a scanning force microscopy study

PubMed

Porter; Eastman; Pace; Bradley

2000-09-01

Polymer-based materials can be incorporated as the active sensing elements in chemiresistor devices. Most of these devices take advantage of the fact that certain polymers will swell when exposed to gaseous analytes. To measure this response, a conducting material such as carbon black is incorporated within the nonconducting polymer matrix. In response to analytes, polymer swelling results in a measurable change in the conductivity of the polymer/carbon composite material. Arrays of these sensors may be used in conjunction with pattern recognition techniques for purposes of analyte recognition and quantification. We have used the technique of scanning force microscopy (SFM) to investigate microstructural changes in carbon-polymer composites formed from the polymers poly (isobutylene) (PIB), poly (vinyl alcohol) (PVA), and poly (ethylene-vinyl acetate) (PEVA) when exposed to the analytes hexane, toluene, water, ethanol, and acetone. Using phase-contrast imaging (PI), changes in the carbon nanoparticle distribution on the surface of the polymer matrix are measured as the polymers are exposed to the analytes in vapor phase. In some but not all cases, the changes were reversible (at the scale of the SFM measurements) upon removal of the analyte vapor. In this paper, we also describe a new type of microsensor based on piezoresistive microcantilever technology. With these new devices, polymeric volume changes accompanying exposure to analyte vapor are measured directly by a piezoresistive microcantilever in direct contact with the polymer. These devices may offer a number of advantages over standard chemiresistor-based sensors.

Enhancement of Natural Convection by Carbon Nanotube Films Covered Microchannel-Surface for Passive Electronic Cooling Devices.

PubMed

Zhang, Guang; Jiang, Shaohui; Yao, Wei; Liu, Changhong

2016-11-16

Owing to the outstanding properties of thermal conduction, lightweight, and chemical durability, carbon nanotubes (CNTs) have revealed promising applications in thermal management materials. Meanwhile, the increasingly popular portable electronics and the rapid development of space technology need lighter weight, smaller size, and more effective thermal management devices. Here, a novel kind of heat dissipation devices based on the superaligned CNT films and underlying microchannels is proposed, and the heat dissipation properties are measured at the natural condition. Distinctive from previous studies, by combining the advantages of microchannels and CNTs, such a novel heat dissipation device enables superior natural convection heat transfer properties. Our findings prove that the novel CNT-based devices could show an 86.6% larger total natural heat dissipation properties than bare copper plate. Further calculations of the radiation and natural convection heat transfer properties demonstrate that the excellent passive cooling properties of these CNT-based devices are primarily caused by the reinforcement of the natural convection heat transfer properties. Furthermore, the heat dissipation mechanisms are briefly discussed, and we propose that the very high heat transfer coefficients and the porous structures of superaligned CNT films play critical roles in reinforcing the natural convection. The novel CNT-based heat dissipation devices also have advantages of energy-saving, free-noise, and without additional accessories. So we believe that the CNT-based heat dissipation devices would replace the traditional metal-finned heat dissipation devices and have promising applications in electronic devices, such as photovoltaic devices, portable electronic devices, and electronic displays.

Electronic Detection of Lectins Using Carbohydrate Functionalized Nanostructures: Graphene versus Carbon Nanotubes

PubMed Central

Chen, Yanan; Vedala, Harindra; Kotchey, Gregg P.; Audfray, Aymeric; Cecioni, Samy; Imberty, Anne; Vidal, Sébastien; Star, Alexander

2012-01-01

Here we investigated the interactions between lectins and carbohydrates using field-effect transistor (FET) devices comprised of chemically converted graphene (CCG) and single-walled carbon nanotubes (SWNTs). Pyrene- and porphyrin-based glycoconjugates were functionalized noncovalently on the surface of CCG-FET and SWNT-FET devices, which were then treated with 2 µM of nonspecific and specific lectins. In particular, three different lectins (PA-IL, PA-IIL and ConA) and three carbohydrate epitopes (galactose, fucose and mannose) were tested. The responses of 36 different devices were compared and rationalized using computer-aided models of carbon nanostructure/glycoconjugate interactions. Glycoconjugates surface coverage in addition to one-dimensional structures of SWNTs resulted in optimal lectin detection. Additionally, lectin titration data of SWNT- and CCG-based biosensors were used to calculate lectin dissociation constants (Kd) and compare them to the values obtained from the isothermal titration microcalorimetry (ITC) technique. PMID:22136380

Graphene Based Ultra-Capacitors for Safer, More Efficient Energy Storage

NASA Technical Reports Server (NTRS)

Roberson, Luke B.; Mackey, Paul J.; Zide, Carson J.

2016-01-01

Current power storage methods must be continuously improved in order to keep up with the increasingly competitive electronics industry. This technological advancement is also essential for the continuation of deep space exploration. Today's energy storage industry relies heavily on the use of dangerous and corrosive chemicals such as lithium and phosphoric acid. These chemicals can prove hazardous to the user if the device is ruptured. Similarly they can damage the environment if they are disposed of improperly. A safer, more efficient alternative is needed across a wide range of NASA missions. One solution would a solid-state carbon based energy storage device. Carbon is a safer, less environmentally hazardous alternative to current energy storage materials. Using the amorphous carbon nanostructure, graphene, this idea of a safer portable energy is possible. Graphene was electrochemically produced in the lab and several coin cell devices were built this summer to create a working prototype of a solid-state graphene battery.

Significant Performance Enhancement in Asymmetric Supercapacitors based on Metal Oxides, Carbon nanotubes and Neutral Aqueous Electrolyte.

PubMed

Singh, Arvinder; Chandra, Amreesh

2015-10-23

Amongst the materials being investigated for supercapacitor electrodes, carbon based materials are most investigated. However, pure carbon materials suffer from inherent physical processes which limit the maximum specific energy and power that can be achieved in an energy storage device. Therefore, use of carbon-based composites with suitable nano-materials is attaining prominence. The synergistic effect between the pseudocapacitive nanomaterials (high specific energy) and carbon (high specific power) is expected to deliver the desired improvements. We report the fabrication of high capacitance asymmetric supercapacitor based on electrodes of composites of SnO2 and V2O5 with multiwall carbon nanotubes and neutral 0.5 M Li2SO4 aqueous electrolyte. The advantages of the fabricated asymmetric supercapacitors are compared with the results published in the literature. The widened operating voltage window is due to the higher over-potential of electrolyte decomposition and a large difference in the work functions of the used metal oxides. The charge balanced device returns the specific capacitance of ~198 F g(-1) with corresponding specific energy of ~89 Wh kg(-1) at 1 A g(-1). The proposed composite systems have shown great potential in fabricating high performance supercapacitors.

Flexible solid-state supercapacitors based on carbon nanoparticles/MnO2 nanorods hybrid structure.

PubMed

Yuan, Longyan; Lu, Xi-Hong; Xiao, Xu; Zhai, Teng; Dai, Junjie; Zhang, Fengchao; Hu, Bin; Wang, Xue; Gong, Li; Chen, Jian; Hu, Chenguo; Tong, Yexiang; Zhou, Jun; Wang, Zhong Lin

2012-01-24

A highly flexible solid-state supercapacitor was fabricated through a simple flame synthesis method and electrochemical deposition process based on a carbon nanoparticles/MnO(2) nanorods hybrid structure using polyvinyl alcohol/H(3)PO(4) electrolyte. Carbon fabric is used as a current collector and electrode (mechanical support), leading to a simplified, highly flexible, and lightweight architecture. The device exhibited good electrochemical performance with an energy density of 4.8 Wh/kg at a power density of 14 kW/kg, and a demonstration of a practical device is also presented, highlighting the path for its enormous potential in energy management. © 2011 American Chemical Society

Material insights of HfO2-based integrated 1-transistor-1-resistor resistive random access memory devices processed by batch atomic layer deposition

PubMed Central

Niu, Gang; Kim, Hee-Dong; Roelofs, Robin; Perez, Eduardo; Schubert, Markus Andreas; Zaumseil, Peter; Costina, Ioan; Wenger, Christian

2016-01-01

With the continuous scaling of resistive random access memory (RRAM) devices, in-depth understanding of the physical mechanism and the material issues, particularly by directly studying integrated cells, become more and more important to further improve the device performances. In this work, HfO2-based integrated 1-transistor-1-resistor (1T1R) RRAM devices were processed in a standard 0.25 μm complementary-metal-oxide-semiconductor (CMOS) process line, using a batch atomic layer deposition (ALD) tool, which is particularly designed for mass production. We demonstrate a systematic study on TiN/Ti/HfO2/TiN/Si RRAM devices to correlate key material factors (nano-crystallites and carbon impurities) with the filament type resistive switching (RS) behaviours. The augmentation of the nano-crystallites density in the film increases the forming voltage of devices and its variation. Carbon residues in HfO2 films turn out to be an even more significant factor strongly impacting the RS behaviour. A relatively higher deposition temperature of 300 °C dramatically reduces the residual carbon concentration, thus leading to enhanced RS performances of devices, including lower power consumption, better endurance and higher reliability. Such thorough understanding on physical mechanism of RS and the correlation between material and device performances will facilitate the realization of high density and reliable embedded RRAM devices with low power consumption. PMID:27312225

Material insights of HfO2-based integrated 1-transistor-1-resistor resistive random access memory devices processed by batch atomic layer deposition

NASA Astrophysics Data System (ADS)

Niu, Gang; Kim, Hee-Dong; Roelofs, Robin; Perez, Eduardo; Schubert, Markus Andreas; Zaumseil, Peter; Costina, Ioan; Wenger, Christian

2016-06-01

With the continuous scaling of resistive random access memory (RRAM) devices, in-depth understanding of the physical mechanism and the material issues, particularly by directly studying integrated cells, become more and more important to further improve the device performances. In this work, HfO2-based integrated 1-transistor-1-resistor (1T1R) RRAM devices were processed in a standard 0.25 μm complementary-metal-oxide-semiconductor (CMOS) process line, using a batch atomic layer deposition (ALD) tool, which is particularly designed for mass production. We demonstrate a systematic study on TiN/Ti/HfO2/TiN/Si RRAM devices to correlate key material factors (nano-crystallites and carbon impurities) with the filament type resistive switching (RS) behaviours. The augmentation of the nano-crystallites density in the film increases the forming voltage of devices and its variation. Carbon residues in HfO2 films turn out to be an even more significant factor strongly impacting the RS behaviour. A relatively higher deposition temperature of 300 °C dramatically reduces the residual carbon concentration, thus leading to enhanced RS performances of devices, including lower power consumption, better endurance and higher reliability. Such thorough understanding on physical mechanism of RS and the correlation between material and device performances will facilitate the realization of high density and reliable embedded RRAM devices with low power consumption.

Wearable Electrocardiogram Monitor Using Carbon Nanotube Electronics and Color-Tunable Organic Light-Emitting Diodes.

PubMed

Koo, Ja Hoon; Jeong, Seongjin; Shim, Hyung Joon; Son, Donghee; Kim, Jaemin; Kim, Dong Chan; Choi, Suji; Hong, Jong-In; Kim, Dae-Hyeong

2017-10-24

With the rapid advances in wearable electronics, the research on carbon-based and/or organic materials and devices has become increasingly important, owing to their advantages in terms of cost, weight, and mechanical deformability. Here, we report an effective material and device design for an integrative wearable cardiac monitor based on carbon nanotube (CNT) electronics and voltage-dependent color-tunable organic light-emitting diodes (CTOLEDs). A p-MOS inverter based on four CNT transistors allows high amplification and thereby successful acquisition of the electrocardiogram (ECG) signals. In the CTOLEDs, an ultrathin exciton block layer of bis[2-(diphenylphosphino)phenyl]ether oxide is used to manipulate the balance of charges between two adjacent emission layers, bis[2-(4,6-difluorophenyl)pyridinato-C 2 ,N](picolinato)iridium(III) and bis(2-phenylquinolyl-N,C(2'))iridium(acetylacetonate), which thereby produces different colors with respect to applied voltages. The ultrathin nature of the fabricated devices supports extreme wearability and conformal integration of the sensor on human skin. The wearable CTOLEDs integrated with CNT electronics are used to display human ECG changes in real-time using tunable colors. These materials and device strategies provide opportunities for next generation wearable health indicators.

All Carbon-Based Photodetectors: An eminent integration of graphite quantum dots and two dimensional graphene

PubMed Central

Cheng, Shih-Hao; Weng, Tong-Min; Lu, Meng-Lin; Tan, Wei-Chun; Chen, Ju-Ying; Chen, Yang-Fang

2013-01-01

Photodetectors with ultrahigh sensitivity based on the composite made with all carbon-based materials consisting of graphite quantum dots (QDs), and two dimensional graphene crystal have been demonstrated. Under light illumination, remarkably, a photocurrent responsivity up to 4 × 107 AW−1 can be obtained. The underlying mechanism is attributed to the spatial separation of photogenerated electrons and holes due to the charge transfer caused by the appropriate band alignment across the interface between graphite QDs and graphene. Besides, the large absorptivity of graphite QDs and the excellent conductivity of the graphene sheet also play significant roles. Our result therefore demonstrates an outstanding illustration for the integration of the distinct properties of nanostructured carbon materials with different dimensionalities to achieve highly efficient devices. Together with the associated mechanism, it paves a valuable step for the further development of all carbon-based, cheap, and non-toxic optoelectronics devices with excellent performance. PMID:24045846

Pentacene-based metal-insulator-semiconductor memory structures utilizing single walled carbon nanotubes as a nanofloating gate

NASA Astrophysics Data System (ADS)

Sleiman, A.; Rosamond, M. C.; Alba Martin, M.; Ayesh, A.; Al Ghaferi, A.; Gallant, A. J.; Mabrook, M. F.; Zeze, D. A.

2012-01-01

A pentacene-based organic metal-insulator-semiconductor memory device, utilizing single walled carbon nanotubes (SWCNTs) for charge storage is reported. SWCNTs were embedded, between SU8 and polymethylmethacrylate to achieve an efficient encapsulation. The devices exhibit capacitance-voltage clockwise hysteresis with a 6 V memory window at ± 30 V sweep voltage, attributed to charging and discharging of SWCNTs. As the applied gate voltage exceeds the SU8 breakdown voltage, charge leakage is induced in SU8 to allow more charges to be stored in the SWCNT nodes. The devices exhibited high storage density (˜9.15 × 1011 cm-2) and demonstrated 94% charge retention due to the superior encapsulation.

Single Wall Carbon Nanotube Alignment Mechanisms for Non-Destructive Evaluation

NASA Technical Reports Server (NTRS)

Hong, Seunghun

2002-01-01

As proposed in our original proposal, we developed a new innovative method to assemble millions of single wall carbon nanotube (SWCNT)-based circuit components as fast as conventional microfabrication processes. This method is based on surface template assembly strategy. The new method solves one of the major bottlenecks in carbon nanotube based electrical applications and, potentially, may allow us to mass produce a large number of SWCNT-based integrated devices of critical interests to NASA.

High power density microbial fuel cell with flexible 3D graphene-nickel foam as anode

NASA Astrophysics Data System (ADS)

Wang, Hanyu; Wang, Gongming; Ling, Yichuan; Qian, Fang; Song, Yang; Lu, Xihong; Chen, Shaowei; Tong, Yexiang; Li, Yat

2013-10-01

The structure and electrical conductivity of anode play a significant role in the power generation of microbial fuel cells (MFCs). In this study, we developed a three-dimensional (3D) reduced graphene oxide-nickel (denoted as rGO-Ni) foam as an anode for MFC through controlled deposition of rGO sheets onto the nickel foam substrate. The loading amount of rGO sheets and electrode surface area can be controlled by the number of rGO loading cycles. 3D rGO-Ni foam anode provides not only a large accessible surface area for microbial colonization and electron mediators, but also a uniform macro-porous scaffold for effective mass diffusion of the culture medium. Significantly, at a steady state of the power generation, the MFC device with flexible rGO-Ni electrodes produced an optimal volumetric power density of 661 W m-3 calculated based on the volume of anode material, or 27 W m-3 based on the volume of the anode chamber. These values are substantially higher than that of plain nickel foam, and other conventional carbon based electrodes (e.g., carbon cloth, carbon felt, and carbon paper) measured in the same conditions. To our knowledge, this is the highest volumetric power density reported for mL-scale MFC device with a pure strain of Shewanella oneidensis MR-1. We also demonstrated that the MFC device can be operated effectively in a batch-mode at least for a week. These new 3D rGO-Ni electrodes show great promise for improving the power generation of MFC devices.The structure and electrical conductivity of anode play a significant role in the power generation of microbial fuel cells (MFCs). In this study, we developed a three-dimensional (3D) reduced graphene oxide-nickel (denoted as rGO-Ni) foam as an anode for MFC through controlled deposition of rGO sheets onto the nickel foam substrate. The loading amount of rGO sheets and electrode surface area can be controlled by the number of rGO loading cycles. 3D rGO-Ni foam anode provides not only a large accessible surface area for microbial colonization and electron mediators, but also a uniform macro-porous scaffold for effective mass diffusion of the culture medium. Significantly, at a steady state of the power generation, the MFC device with flexible rGO-Ni electrodes produced an optimal volumetric power density of 661 W m-3 calculated based on the volume of anode material, or 27 W m-3 based on the volume of the anode chamber. These values are substantially higher than that of plain nickel foam, and other conventional carbon based electrodes (e.g., carbon cloth, carbon felt, and carbon paper) measured in the same conditions. To our knowledge, this is the highest volumetric power density reported for mL-scale MFC device with a pure strain of Shewanella oneidensis MR-1. We also demonstrated that the MFC device can be operated effectively in a batch-mode at least for a week. These new 3D rGO-Ni electrodes show great promise for improving the power generation of MFC devices. Electronic supplementary information (ESI) available. See DOI: 10.1039/c3nr03487a

Carbon and metal nanotube hybrid structures on graphene as efficient electron field emitters

NASA Astrophysics Data System (ADS)

Heo, Kwang; Lee, Byung Yang; Lee, Hyungwoo; Cho, Dong-guk; Arif, Muhammad; Kim, Kyu Young; Choi, Young Jin; Hong, Seunghun

2016-07-01

We report a facile and efficient method for the fabrication of highly-flexible field emission devices by forming tubular hybrid structures based on carbon nanotubes (CNTs) and nickel nanotubes (Ni NTs) on graphene-based flexible substrates. By employing an infiltration process in anodic alumina oxide (AAO) templates followed by Ni electrodeposition, we could fabricate CNT-wrapped Ni NT/graphene hybrid structures. During the electrodeposition process, the CNTs served as Ni nucleation sites, resulting in a large-area array of high aspect-ratio field emitters composed of CNT-wrapped Ni NT hybrid structures. As a proof of concepts, we demonstrate that high-quality flexible field emission devices can be simply fabricated using our method. Remarkably, our proto-type field emission devices exhibited a current density higher by two orders of magnitude compared to other devices fabricated by previous methods, while maintaining its structural integrity in various bending deformations. This novel fabrication strategy can be utilized in various applications such as optoelectronic devices, sensors and energy storage devices.

Carbon and metal nanotube hybrid structures on graphene as efficient electron field emitters.

PubMed

Heo, Kwang; Lee, Byung Yang; Lee, Hyungwoo; Cho, Dong-Guk; Arif, Muhammad; Kim, Kyu Young; Choi, Young Jin; Hong, Seunghun

2016-07-08

We report a facile and efficient method for the fabrication of highly-flexible field emission devices by forming tubular hybrid structures based on carbon nanotubes (CNTs) and nickel nanotubes (Ni NTs) on graphene-based flexible substrates. By employing an infiltration process in anodic alumina oxide (AAO) templates followed by Ni electrodeposition, we could fabricate CNT-wrapped Ni NT/graphene hybrid structures. During the electrodeposition process, the CNTs served as Ni nucleation sites, resulting in a large-area array of high aspect-ratio field emitters composed of CNT-wrapped Ni NT hybrid structures. As a proof of concepts, we demonstrate that high-quality flexible field emission devices can be simply fabricated using our method. Remarkably, our proto-type field emission devices exhibited a current density higher by two orders of magnitude compared to other devices fabricated by previous methods, while maintaining its structural integrity in various bending deformations. This novel fabrication strategy can be utilized in various applications such as optoelectronic devices, sensors and energy storage devices.

Single walled carbon nanotube-based stochastic resonance device with molecular self-noise source

NASA Astrophysics Data System (ADS)

Fujii, Hayato; Setiadi, Agung; Kuwahara, Yuji; Akai-Kasaya, Megumi

2017-09-01

Stochastic resonance (SR) is an intrinsic noise usage system for small-signal sensing found in various living creatures. The noise-enhanced signal transmission and detection system, which is probabilistic but consumes low power, has not been used in modern electronics. We demonstrated SR in a summing network based on a single-walled carbon nanotube (SWNT) device that detects small subthreshold signals with very low current flow. The nonlinear current-voltage characteristics of this SWNT device, which incorporated Cr electrodes, were used as the threshold level of signal detection. The adsorption of redox-active polyoxometalate molecules on SWNTs generated additional noise, which was utilized as a self-noise source. To form a summing network SR device, a large number of SWNTs were aligned parallel to each other between the electrodes, which increased the signal detection ability. The functional capabilities of the present small-size summing network SR device, which rely on dense nanomaterials and exploit intrinsic spontaneous noise at room temperature, offer a glimpse of future bio-inspired electronic devices.

Carbon-Nanotube Fibers for Wearable Devices and Smart Textiles.

PubMed

Di, Jiangtao; Zhang, Xiaohua; Yong, Zhenzhong; Zhang, Yongyi; Li, Da; Li, Ru; Li, Qingwen

2016-12-01

Carbon-nanotube (CNT) fibers integrate such properties as high mechanical strength, extraordinary structural flexibility, high thermal and electrical conductivities, novel corrosion and oxidation resistivities, and high surface area, which makes them a very promising candidate for next-generation smart textiles and wearable devices. A brief review of the preparation of CNT fibers and recently developed CNT-fiber-based flexible and functional devices, which include artificial muscles, electrochemical double-layer capacitors, lithium-ion batteries, solar cells, and memristors, is presented. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Pyrolyzed-parylene based sensors and method of manufacture

NASA Technical Reports Server (NTRS)

Tai, Yu-Chong (Inventor); Liger, Matthieu (Inventor); Miserendino, Scott (Inventor); Konishi, Satoshi (Inventor)

2007-01-01

A method (and resulting structure) for fabricating a sensing device. The method includes providing a substrate comprising a surface region and forming an insulating material overlying the surface region. The method also includes forming a film of carbon based material overlying the insulating material and treating to the film of carbon based material to pyrolyzed the carbon based material to cause formation of a film of substantially carbon based material having a resistivity ranging within a predetermined range. The method also provides at least a portion of the pyrolyzed carbon based material in a sensor application and uses the portion of the pyrolyzed carbon based material in the sensing application. In a specific embodiment, the sensing application is selected from chemical, humidity, piezoelectric, radiation, mechanical strain or temperature.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Mallajosyula, Arun T.; Nie, Wanyi; Gupta, Gautam

A prerequisite for carbon nanotube-based optoelectronic devices is the ability to sort them into a pure semiconductor phase. One of the most common sorting routes is enabled through using specific wrapping polymers. Here we show that subtle changes in the polymer structure can have a dramatic influence on the figures of merit of a carbon nanotube-based photovoltaic device. By comparing two commonly used polyfluorenes (PFO and PFO-BPy) for wrapping (7,5) and (6,5) chirality SWCNTs, we demonstrate that they have contrasting effects on the device efficiency. We attribute this to the differences in their ability to efficiently transfer charge. Although PFOmore » may act as an efficient interfacial layer at the anode, PFO-BPy, having the additional pyridine side groups, forms a high resistance layer degrading the device efficiency. By comparing PFO|C 60 and C 60-only devices, we found that presence of a PFO layer at low optical densities resulted in the increase of all three solar cell parameters, giving nearly an order of magnitude higher efficiency over that of C 60-only devices. In addition, with a relatively higher contribution to photocurrent from the PFO-C 60 interface, an open circuit voltage of 0.55 V was obtained for PFO-(7,5)-C 60 devices. On the other hand, PFO-BPy does not affect the open circuit voltage but drastically reduces the short circuit current density. Lastly, these results indicate that the charge transport properties and energy levels of the sorting polymers have to be taken into account to fully understand their effect on carbon nanotube-based solar cells.« less

Investigation of Basic Mechanisms of Radiation Effects in Carbon-Based Electronic Materials

DTIC Science & Technology

2017-06-01

materials characterization, and carbon nanotube diodes, FET, and PZT-memory test device structures for electrical measurements. Pre - and post -irradiation...definition (Radiation exposure) Task 2) The grantee shall perform testing to include: - Radiation testing . May be multiple types. - Pre and post -rad...technologies for electronic devices. Experiential radiation testing has included exposure to 10 keV X-rays, 4 MeV protons, heavy ions, and Ultra

Electrical conductivity of nanocomposites based on carbon nanotubes: a 3D multiscale modeling approach

NASA Astrophysics Data System (ADS)

Grabowski, Krzysztof; Zbyrad, Paulina; Staszewski, Wieslaw J.; Uhl, Tadeusz; Wiatr, Kazimierz; Packo, Pawel

2016-04-01

Remarkable electrical properties of carbon nanotubes (CNT) have lead to increased interest in studying CNT- based devices. Many of current researches are devoted to using all kinds of carbon nanomaterials in the con- struction of sensory elements. One of the most common applications is the development of high performance, large scale sensors. Due to the remarkable conductivity of CNT's such devices represent very high sensitivity. However, there are no sufficient tools for studying and designing such sensors. The main objective of this paper is to develop and validate a multiscale numerical model for a carbon nanotubes based sensor. The device utilises the change of electrical conductivity of a nanocomposite material under applied deformation. The nanocomposite consists of a number of CNTs dispersed in polymer matrix. The paper is devoted to the analysis of the impact of spatial distribution of carbon nanotubes in polymer matrix on electrical conductivity of the sensor. One of key elements is also to examine the impact of strain on electric charge ow in such anisotropic composite structures. In the following work a multiscale electro-mechanical model for CNT - based nanocomposites is proposed. The model comprises of two length scales, namely the meso- and the macro-scale for mechanical and electrical domains. The approach allows for evaluation of macro-scale mechanical response of a strain sensor. Electrical properties of polymeric material with certain CNT fractions were derived considering electrical properties of CNTs, their contact and the tunnelling effect.

Fabrication of 1-dimension nano-material-based device and its electrical characteristics

NASA Astrophysics Data System (ADS)

Yang, Xing; Zhou, Zhaoying; Zheng, Fuzhong; Zhang, Min

2008-12-01

In recent years, many kinds of 1-dimension nano-materials (Carbon nanotube, ZnO nanobelt and nanowire etc.) continue to emerge which exhibit distinct and unique electromechanical, piezoelectric, photoelectrical properties. In this paper, a 1-dimension nano-materials-based device was proposed. The bottom-up and top-down combined process were used for constructing CNT-array-based device and ZnO nanowire device. The electrical characteristics of the 1D nano-materials-based devices were also investigated. The measurement results of electrical characteristics demonstrate that it is ohm electrical contact behavior between the nano-material and micro-electrodes in the proposed device which also have the field effect. The proposed 1D nano-material-based device shows the application potential in the sensing fields.

Many faces of carbon

NASA Astrophysics Data System (ADS)

Wang, Qian; Zhang, Shunhong; Jena, Puru

2016-12-01

Due to the special electronic configuration, small atomic size, light mass, and flexible bonding features, carbon exhibits many different structural configurations with very different physical and chemical properties. Here we focus our discussion on three recent forms of carbon, namely, metallic carbon, magnetic carbon, and all-pentagon-based carbon. The metallic carbon can be used for metallic interconnects in future electronic circuits, nano devices and microprocessors while the magnetic carbon can have applications in spintronics. All-pentagon-based carbon nano-structure, penta-graphene, not only expands the family of carbon materials with a number of new features, but also provides the materials basis for the 2D packing of pentagons pursued by mathematicians for almost a century.

Carbon Based Transistors and Nanoelectronic Devices

NASA Astrophysics Data System (ADS)

Rouhi, Nima

Carbon based materials (carbon nanotube and graphene) has been extensively researched during the past decade as one of the promising materials to be used in high performance device technology. In long term it is thought that they may replace digital and/or analog electronic devices, due to their size, near-ballistic transport, and high stability. However, a more realistic point of insertion into market may be the printed nanoelectronic circuits and sensors. These applications include printed circuits for flexible electronics and displays, large-scale bendable electrical contacts, bio-membranes and bio sensors, RFID tags, etc. In order to obtain high performance thin film transistors (as the basic building block of electronic circuits) one should be able to manufacture dense arrays of all semiconducting nanotubes. Besides, graphene synthesize and transfer technology is in its infancy and there is plenty of room to improve the current techniques. To realize the performance of nanotube and graphene films in such systems, we need to economically fabricate large-scale devices based on these materials. Following that the performance control over such devices should also be considered for future design variations for broad range of applications. Here we have first investigated carbon nanotube ink as the base material for our devices. The primary ink used consisted of both metallic and semiconducting nanotubes which resulted in networks suitable for moderate-resistivity electrical connections (such as interconnects) and rfmatching circuits. Next, purified all-semiconducting nanotube ink was used to fabricate waferscale, high performance (high mobility, and high on/off ratio) thin film transistors for printed electronic applications. The parameters affecting device performance were studied in detail to establish a roadmap for the future of purified nanotube ink printed thin film transistors. The trade of between mobility and on/off ratio of such devices was studied and the effect of nanotube network density was explained in detail. On the other hand, graphene transfer technology was explored here as well. Annealing techniques were utilized to deposit clean graphene on arbitrary substrates. Raman spectroscopy and Raman data analysis was used to confirm the clean process. Furthermore, suspended graphene membrane was fabricated using single and multi-layer graphene films. This can make a major impact on graphene based transistors and bio-nano sensors technology.

Devices and methods to detect and quantify trace gases

DOEpatents

Allendorf, Mark D.; Robinson, Alex

2016-05-03

Sensing devices based on a surface acoustic wave ("SAW") device coated with an absorbent crystalline or amorphous layer for detecting at least one chemical analyte in a gaseous carrier. Methods for detecting the presence of a chemical analyte in a gaseous carrier using such devices are also disclosed. The sensing devices and methods for their use may be configured for sensing chemical analytes selected from the group consisting of water vapor, carbon dioxide, methanol, ethanol, carbon monoxide, nitric oxide, nitrous oxide, organic amines, organic compounds containing NO.sub.2 groups, halogenated hydrocarbons, acetone, hexane, toluene, isopropanol, alcohols, alkanes, alkenes, benzene, functionalized aromatics, ammonia (NH.sub.3), phosgene (COCl.sub.2), sulfur mustard, nerve agents, sulfur dioxide, tetrahydrofuran (THF) and methyltertbutyl ether (MTBE) and combinations thereof.

Carbon nanotube vacuum gauges utilizing long, dissipative tubes

NASA Astrophysics Data System (ADS)

Kaul, Anupama B.; Manohara, Harish M.

2008-04-01

A carbon nanotube-based thermal conductivity vacuum gauge is described which utilizes 5-10 μm long diffusively contacted SWNTs for vacuum sensing. By etching the thermal SiO II beneath the tubes and minimizing heat conduction through the substrate, pressure sensitivity was extended toward higher vacuums. The pressure response of unannealed and annealed devices was compared to that of released devices. The released devices showed sensitivity to pressure as low as 1 x 10 -6 Torr. The sensitivity increased more dramatically with power for the released device compared to that of the unreleased device. Low temperature electronic transport measurements of the tubes were suggestive of a thermally activated hopping mechanism where the activation energy for hopping was calculated to be ~ 39 meV.

21 CFR 868.1400 - Carbon dioxide gas analyzer.

Code of Federal Regulations, 2011 CFR

2011-04-01

... 21 Food and Drugs 8 2011-04-01 2011-04-01 false Carbon dioxide gas analyzer. 868.1400 Section 868...) MEDICAL DEVICES ANESTHESIOLOGY DEVICES Diagnostic Devices § 868.1400 Carbon dioxide gas analyzer. (a) Identification. A carbon dioxide gas analyzer is a device intended to measure the concentration of carbon dioxide...

21 CFR 868.1400 - Carbon dioxide gas analyzer.

Code of Federal Regulations, 2010 CFR

2010-04-01

... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Carbon dioxide gas analyzer. 868.1400 Section 868...) MEDICAL DEVICES ANESTHESIOLOGY DEVICES Diagnostic Devices § 868.1400 Carbon dioxide gas analyzer. (a) Identification. A carbon dioxide gas analyzer is a device intended to measure the concentration of carbon dioxide...

21 CFR 868.1400 - Carbon dioxide gas analyzer.

Code of Federal Regulations, 2013 CFR

2013-04-01

... 21 Food and Drugs 8 2013-04-01 2013-04-01 false Carbon dioxide gas analyzer. 868.1400 Section 868...) MEDICAL DEVICES ANESTHESIOLOGY DEVICES Diagnostic Devices § 868.1400 Carbon dioxide gas analyzer. (a) Identification. A carbon dioxide gas analyzer is a device intended to measure the concentration of carbon dioxide...

21 CFR 868.1400 - Carbon dioxide gas analyzer.

Code of Federal Regulations, 2014 CFR

2014-04-01

... 21 Food and Drugs 8 2014-04-01 2014-04-01 false Carbon dioxide gas analyzer. 868.1400 Section 868...) MEDICAL DEVICES ANESTHESIOLOGY DEVICES Diagnostic Devices § 868.1400 Carbon dioxide gas analyzer. (a) Identification. A carbon dioxide gas analyzer is a device intended to measure the concentration of carbon dioxide...

Recent progress on fabrication of memristor and transistor-based neuromorphic devices for high signal processing speed with low power consumption

NASA Astrophysics Data System (ADS)

Hadiyawarman; Budiman, Faisal; Goldianto Octensi Hernowo, Detiza; Pandey, Reetu Raj; Tanaka, Hirofumi

2018-03-01

The advanced progress of electronic-based devices for artificial neural networks and recent trends in neuromorphic engineering are discussed in this review. Recent studies indicate that the memristor and transistor are two types of devices that can be implemented as neuromorphic devices. The electrical switching characteristics and physical mechanism of neuromorphic devices based on metal oxide, metal sulfide, silicon, and carbon materials are broadly covered in this review. Moreover, the switching performance comparison of several materials mentioned above are well highlighted, which would be useful for the further development of memristive devices. Recent progress in synaptic devices and the application of a switching device in the learning process is also discussed in this paper.

Response of asymmetric carbon nanotube network devices to sub-terahertz and terahertz radiation

DOE Office of Scientific and Technical Information (OSTI.GOV)

Gayduchenko, I., E-mail: igorandg@gmail.com, E-mail: gefedorov@mail.ru; National Research Centre “Kurchatov Institute,” Moscow 123128; Kardakova, A.

2015-11-21

Demand for efficient terahertz radiation detectors resulted in intensive study of the asymmetric carbon nanostructures as a possible solution for that problem. It was maintained that photothermoelectric effect under certain conditions results in strong response of such devices to terahertz radiation even at room temperature. In this work, we investigate different mechanisms underlying the response of asymmetric carbon nanotube (CNT) based devices to sub-terahertz and terahertz radiation. Our structures are formed with CNT networks instead of individual CNTs so that effects probed are more generic and not caused by peculiarities of an individual nanoscale object. We conclude that the DCmore » voltage response observed in our structures is not only thermal in origin. So called diode-type response caused by asymmetry of the device IV characteristic turns out to be dominant at room temperature. Quantitative analysis provides further routes for the optimization of the device configuration, which may result in appearance of novel terahertz radiation detectors.« less

Integrated single-walled carbon nanotube/microfluidic devices for the study of the sensing mechanism of nanotube sensors.

PubMed

Fu, Qiang; Liu, Jie

2005-07-21

A method to fabricate integrated single-walled carbon nanotube/microfluidic devices was developed. This simple process could be used to directly prepare nanotube thin film transistors within the microfluidic channel and to register SWNT devices with the microfludic channel without the need of an additional alignment step. The microfluidic device was designed to have several inlets that deliver multiple liquid flows to a single main channel. The location and width of each flow in the main channel could be controlled by the relative flow rates. This capability enabled us to study the effect of the location and the coverage area of the liquid flow that contained charged molecules on the conduction of the nanotube devices, providing important information on the sensing mechanism of carbon nanotube sensors. The results showed that in a sensor based on a nanotube thin film field effect transistor, the sensing signal came from target molecules absorbed on or around the nanotubes. The effect from adsorption on metal electrodes was weak.

Suspended Carbon Nanotubes for Humidity Sensing

PubMed Central

Arunachalam, Shivaram; Gupta, Anubha A.; Izquierdo, Ricardo

2018-01-01

A room temperature microfabrication technique using SU8, an epoxy-based highly functional photoresist as a sacrificial layer, is developed to obtain suspended aligned carbon nanotube beams. The humidity-sensing characteristics of aligned suspended single-walled carbon nanotube films are studied. A comparative study between suspended and non-suspended architectures is done by recording the resistance change in the nanotubes under humidity. For the tests, the humidity was varied from 15% to 98% RH. A comparative study between suspended and non-suspended devices shows that the response and recovery times of the suspended devices was found to be almost 3 times shorter than the non-suspended devices. The suspended devices also showed minimal hysteresis even after 10 humidity cycles, and also exhibit enhanced sensitivity. Repeatability tests were performed by subjecting the sensors to continuous humidification cycles. All tests reported here have been performed using pristine non-functionalized nanotubes. PMID:29786661

Suspended Carbon Nanotubes for Humidity Sensing.

PubMed

Arunachalam, Shivaram; Gupta, Anubha A; Izquierdo, Ricardo; Nabki, Frederic

2018-05-22

A room temperature microfabrication technique using SU8, an epoxy-based highly functional photoresist as a sacrificial layer, is developed to obtain suspended aligned carbon nanotube beams. The humidity-sensing characteristics of aligned suspended single-walled carbon nanotube films are studied. A comparative study between suspended and non-suspended architectures is done by recording the resistance change in the nanotubes under humidity. For the tests, the humidity was varied from 15% to 98% RH. A comparative study between suspended and non-suspended devices shows that the response and recovery times of the suspended devices was found to be almost 3 times shorter than the non-suspended devices. The suspended devices also showed minimal hysteresis even after 10 humidity cycles, and also exhibit enhanced sensitivity. Repeatability tests were performed by subjecting the sensors to continuous humidification cycles. All tests reported here have been performed using pristine non-functionalized nanotubes.

The Carbon-Water Interface: Modeling Challenges and Opportunities for the Water-Energy Nexus.

PubMed

Striolo, Alberto; Michaelides, Angelos; Joly, Laurent

2016-06-07

Providing clean water and sufficient affordable energy to all without compromising the environment is a key priority in the scientific community. Many recent studies have focused on carbon-based devices in the hope of addressing this grand challenge, justifying and motivating detailed studies of water in contact with carbonaceous materials. Such studies are becoming increasingly important because of the miniaturization of newly proposed devices, with ubiquitous nanopores, large surface-to-volume ratio, and many, perhaps most of the water molecules in contact with a carbon-based surface. In this brief review, we discuss some recent advances obtained via simulations and experiments in the development of carbon-based materials for applications in water desalination. We suggest possible ways forward, with particular emphasis on the synergistic combination of experiments and simulations, with simulations now sometimes offering sufficient accuracy to provide fundamental insights. We also point the interested reader to recent works that complement our short summary on the state of the art of this important and fascinating field.

Vertically aligned carbon nanotubes for microelectrode arrays applications.

PubMed

Castro Smirnov, J R; Jover, Eric; Amade, Roger; Gabriel, Gemma; Villa, Rosa; Bertran, Enric

2012-09-01

In this work a methodology to fabricate carbon nanotube based electrodes using plasma enhanced chemical vapour deposition has been explored and defined. The final integrated microelectrode based devices should present specific properties that make them suitable for microelectrode arrays applications. The methodology studied has been focused on the preparation of highly regular and dense vertically aligned carbon nanotube (VACNT) mat compatible with the standard lithography used for microelectrode arrays technology.

Significant Performance Enhancement in Asymmetric Supercapacitors based on Metal Oxides, Carbon nanotubes and Neutral Aqueous Electrolyte

PubMed Central

Singh, Arvinder; Chandra, Amreesh

2015-01-01

Amongst the materials being investigated for supercapacitor electrodes, carbon based materials are most investigated. However, pure carbon materials suffer from inherent physical processes which limit the maximum specific energy and power that can be achieved in an energy storage device. Therefore, use of carbon-based composites with suitable nano-materials is attaining prominence. The synergistic effect between the pseudocapacitive nanomaterials (high specific energy) and carbon (high specific power) is expected to deliver the desired improvements. We report the fabrication of high capacitance asymmetric supercapacitor based on electrodes of composites of SnO2 and V2O5 with multiwall carbon nanotubes and neutral 0.5 M Li2SO4 aqueous electrolyte. The advantages of the fabricated asymmetric supercapacitors are compared with the results published in the literature. The widened operating voltage window is due to the higher over-potential of electrolyte decomposition and a large difference in the work functions of the used metal oxides. The charge balanced device returns the specific capacitance of ~198 F g−1 with corresponding specific energy of ~89 Wh kg−1 at 1 A g−1. The proposed composite systems have shown great potential in fabricating high performance supercapacitors. PMID:26494197

Significant Performance Enhancement in Asymmetric Supercapacitors based on Metal Oxides, Carbon nanotubes and Neutral Aqueous Electrolyte

NASA Astrophysics Data System (ADS)

Singh, Arvinder; Chandra, Amreesh

2015-10-01

Amongst the materials being investigated for supercapacitor electrodes, carbon based materials are most investigated. However, pure carbon materials suffer from inherent physical processes which limit the maximum specific energy and power that can be achieved in an energy storage device. Therefore, use of carbon-based composites with suitable nano-materials is attaining prominence. The synergistic effect between the pseudocapacitive nanomaterials (high specific energy) and carbon (high specific power) is expected to deliver the desired improvements. We report the fabrication of high capacitance asymmetric supercapacitor based on electrodes of composites of SnO2 and V2O5 with multiwall carbon nanotubes and neutral 0.5 M Li2SO4 aqueous electrolyte. The advantages of the fabricated asymmetric supercapacitors are compared with the results published in the literature. The widened operating voltage window is due to the higher over-potential of electrolyte decomposition and a large difference in the work functions of the used metal oxides. The charge balanced device returns the specific capacitance of ~198 F g-1 with corresponding specific energy of ~89 Wh kg-1 at 1 A g-1. The proposed composite systems have shown great potential in fabricating high performance supercapacitors.

Investigation of the optical and electrical characteristics of solution-processed poly (3 hexylthiophene) (P3HT): multiwall carbon nanotube (MWCNT) composite-based devices

NASA Astrophysics Data System (ADS)

Rathore, Priyanka; Mohan Singh Negi, Chandra; Singh Verma, Ajay; Singh, Amarjeet; Chauhan, Gayatri; Regis Inigo, Anto; Gupta, Saral K.

2017-08-01

Devices comprised of solution-processed poly (3-hexylthiophene) (P3HT)/multiwall carbon nanotubes (MWCNTs), with various concentrations of MWCNTs, were fabricated and characterized. The morphology of the P3HT: MWCNT nanocomposite was characterized by using field emission scanning electron microscopy (FESEM). The optical characteristics of the nanocomposite were studied by UV/VIS/NIR spectroscopy and Raman spectroscopy. The electrical properties of the fabricated devices were characterized by measuring the current density-voltage (J-V) characteristics. While the J-V characteristics of a pristine P3HT device reveal thermal injection limited charge transport, the P3HT: MWCNT nanocomposite-based devices exhibit three distinct voltage-dependent conduction regimes. The fitting curve with measured data reveals Ohmic conduction for a low voltage range, a trap-charge limited conduction (TCLC) process at an intermediate voltage range followed by a trap free space-charge limited conduction (SCLC) process at much higher voltages. A fundamental understanding of this work can assist in creating new charge transport pathways which will provide new avenues for the development of highly efficient polymer-based optoelectronic devices.

Functionalization of carbon fiber tows with ZnO nanorods for stress sensor integration in smart composite materials.

PubMed

Calestani, D; Culiolo, M; Villani, M; Delmonte, D; Solzi, M; Kim, Tae-Yun; Kim, Sang-Woo; Marchini, L; Zappettini, A

2018-08-17

The physical and operating principle of a stress sensor, based on two crossing carbon fibers functionalized with ZnO nanorod-shaped nanostructures, was recently demonstrated. The functionalization process has been here extended to tows made of one thousand fibers, like those commonly used in industrial processing, to prove the idea that the same working principle can be exploited in the creation of smart sensing carbon fiber composites. A stress-sensing device made of two functionalized tows, fixed with epoxy resin and crossing like in a typical carbon fiber texture, was successfully tested. Piezoelectric properties of single nanorods, as well as those of the test device, were measured and discussed.

Carbon-nanotube-based liquids: a new class of nanomaterials and their applications

NASA Astrophysics Data System (ADS)

Phan, Ngoc Minh; Thang Bui, Hung; Nguyen, Manh Hong; Khoi Phan, Hong

2014-03-01

Carbon-nanotube-based liquids—a new class of nanomaterials—have shown many interesting properties and distinctive features offering unprecedented potential for many applications. This paper summarizes the recent progress on the study of the preparation, characterization and properties of carbon-nanotube-based liquids including so-called nanofluids, nanolubricants and different kinds of nanosolutions containing multi-walled carbon nanotubes/single-walled carbon nanotubes/graphene. A broad range of current and future applications of these nanomaterials in the fields of energy saving, power electronic and optoelectronic devices, biotechnology and agriculture are presented. The paper also identifies challenges and opportunities for future research.

Working cycles of devices based on bistable carbon nanotubes

NASA Astrophysics Data System (ADS)

Shklyaev, Oleg; Mockensturm, Eric; Crespi, Vincent; Carbon Nanotubes Collaboration

2013-03-01

Shape-changing nanotubes are an example of variable-shape sp2 carbon-based systems where the competition between strain and surface energies can be moderated by an externally controllable stimuli such as applied voltage, temperature, or pressure of gas encapsulated inside the tube. Using any of these stimuli one can transition a bistable carbon nanotube between the collapsed and inflated states and thus perform mechanical work. During the working cycle of such a device, energy from an electric or heat source is transferred to mechanical energy. Combinations of these stimuli allow the system to convert energy between different sources using the bistable shape-changing tube as a mediator. For example, coupling a bistable carbon nanotube to the heat and charge reservoirs can enable energy transfer between heat and electric forms. The developed theory can be extended to other nano-systems which change configurations in response to external stimuli.

Emerging Carbon and Post-Carbon Nanomaterial Inks for Printed Electronics.

PubMed

Secor, Ethan B; Hersam, Mark C

2015-02-19

Carbon and post-carbon nanomaterials present desirable electrical, optical, chemical, and mechanical attributes for printed electronics, offering low-cost, large-area functionality on flexible substrates. In this Perspective, recent developments in carbon nanomaterial inks are highlighted. Monodisperse semiconducting single-walled carbon nanotubes compatible with inkjet and aerosol jet printing are ideal channels for thin-film transistors, while inkjet, gravure, and screen-printable graphene-based inks are better-suited for electrodes and interconnects. Despite the high performance achieved in prototype devices, additional effort is required to address materials integration issues encountered in more complex systems. In this regard, post-carbon nanomaterial inks (e.g., electrically insulating boron nitride and optically active transition-metal dichalcogenides) present promising opportunities. Finally, emerging work to extend these nanomaterial inks to three-dimensional printing provides a path toward nonplanar devices. Overall, the superlative properties of these materials, coupled with versatile assembly by printing techniques, offer a powerful platform for next-generation printed electronics.

Carbon nanomaterials for non-volatile memories

NASA Astrophysics Data System (ADS)

Ahn, Ethan C.; Wong, H.-S. Philip; Pop, Eric

2018-03-01

Carbon can create various low-dimensional nanostructures with remarkable electronic, optical, mechanical and thermal properties. These features make carbon nanomaterials especially interesting for next-generation memory and storage devices, such as resistive random access memory, phase-change memory, spin-transfer-torque magnetic random access memory and ferroelectric random access memory. Non-volatile memories greatly benefit from the use of carbon nanomaterials in terms of bit density and energy efficiency. In this Review, we discuss sp2-hybridized carbon-based low-dimensional nanostructures, such as fullerene, carbon nanotubes and graphene, in the context of non-volatile memory devices and architectures. Applications of carbon nanomaterials as memory electrodes, interfacial engineering layers, resistive-switching media, and scalable, high-performance memory selectors are investigated. Finally, we compare the different memory technologies in terms of writing energy and time, and highlight major challenges in the manufacturing, integration and understanding of the physical mechanisms and material properties.

Carbon nanotube woven textile photodetector

NASA Astrophysics Data System (ADS)

Zubair, Ahmed; Wang, Xuan; Mirri, Francesca; Tsentalovich, Dmitri E.; Fujimura, Naoki; Suzuki, Daichi; Soundarapandian, Karuppasamy P.; Kawano, Yukio; Pasquali, Matteo; Kono, Junichiro

2018-01-01

The increasing interest in mobile and wearable technology demands the enhancement of functionality of clothing through incorporation of sophisticated architectures of multifunctional materials. Flexible electronic and photonic devices based on organic materials have made impressive progress over the past decade, but higher performance, simpler fabrication, and most importantly, compatibility with woven technology are desired. Here we report on the development of a weaved, substrateless, and polarization-sensitive photodetector based on doping-engineered fibers of highly aligned carbon nanotubes. This room-temperature-operating, self-powered detector responds to radiation in an ultrabroad spectral range, from the ultraviolet to the terahertz, through the photothermoelectric effect, with a low noise-equivalent power (a few nW/Hz 1 /2) throughout the range and with a Z T -factor value that is twice as large as that of previously reported carbon nanotube-based photothermoelectric photodetectors. Particularly, we fabricated a ˜1 -m-long device consisting of tens of p+-p- junctions and weaved it into a shirt. This device demonstrated a collective photoresponse of the series-connected junctions under global illumination. The performance of the device did not show any sign of deterioration through 200 bending tests with a bending radius smaller than 100 μ m as well as standard washing and ironing cycles. This unconventional photodetector will find applications in wearable technology that require detection of electromagnetic radiation.

An experimental investigation of using carbon foam-PCM-MWCNTs composite materials for thermal management of electronic devices under pulsed power modes

NASA Astrophysics Data System (ADS)

Alshaer, W. G.; Rady, M. A.; Nada, S. A.; Palomo Del Barrio, Elena; Sommier, Alain

2017-02-01

The present article reports on a detailed experimental investigation of using carbon foam-PCM-MWCNTs composite materials for thermal management (TM) of electronic devices subjected to pulsed power. The TM module was fabricated by infiltrating paraffin wax (RT65) as a phase change material (PCM) and multi walled carbon nanotubes (MWCNTs) as a thermal conductivity enhancer in a carbon foam as a base structure. Two carbon foam materials of low and high values of thermal conductivities, CF20 and KL1-250 (3.1 and 40 W/m K), were tested as a base structure for the TM modules. Tests were conducted at different power intensities and power cycling/loading modes. Results showed that for all power varying modes and all carbon foams, the infiltration of RT65 into carbon foam reduces the temperature of TM module and results in damping the temperature spikes height. Infiltration of MWCNTS into RT65 further improves the effectiveness of TM module. Temperature damping was more pronounced in stand-alone pulsed power cycles as compared to pulsed power spikes modes. The effectiveness of inclusion of RT65 and RT65/MWCNTs in damping the temperature spikes height is remarkable in TM modules based on KL1-250 as compared to CF-20.

Use of organic precursors and graphenes in the controlled synthesis of carbon-containing nanomaterials for energy storage and conversion.

PubMed

Yang, Shubin; Bachman, Robert E; Feng, Xinliang; Müllen, Klaus

2013-01-15

The development of high-performance electrochemical energy storage and conversion devices, including supercapacitors, lithium-ion batteries, and fuel cells, is an important step on the road to alternative energy technologies. Carbon-containing nanomaterials (CCNMs), defined here as pure carbon materials and carbon/metal (oxide, hydroxide) hybrids with structural features on the nanometer scale, show potential application in such devices. Because of their pronounced electrochemical activity, high chemical and thermal stability and low cost, researchers are interested in CCNMs to serve as electrodes in energy-related devices. Various all-carbon materials are candidates for electrochemical energy storage and conversion devices. Furthermore, carbon-based hybrid materials, which consist of a carbon component with metal oxide- or metal hydroxide-based nanostructures, offer the opportunity to combine the attractive properties of these two components and tune the behavior of the resulting materials. As such, the design and synthesis of CCNMs provide an attractive route for the construction of high-performance electrode materials. Studies in these areas have revealed that both the composition and the fabrication protocol employed in preparing CCNMs influence the morphology and microstructure of the resulting material and its electrochemical performance. Consequently, researchers have developed several synthesis strategies, including hard-templated, soft-templated, and template-free synthesis of CCNMs. In this Account, we focus on recent advances in the controlled synthesis of such CCNMs and the potential of the resulting materials for energy storage or conversion applications. The Account is divided into four major categories based on the carbon precursor employed in the synthesis: low molecular weight organic or organometallic molecules, hyperbranched or cross-linked polymers consisting of aromatic subunits, self-assembling discotic molecules, and graphenes. In each case, we highlight representative examples of CCNMs with both new nanostructures and electrochemical performance suitable for energy storage or conversion applications. In addition, this Account provides an overall perspective on the current state of efforts aimed at the controlled synthesis of CCNMs and identifies some of the remaining challenges.

21 CFR 868.5300 - Carbon dioxide absorbent.

Code of Federal Regulations, 2010 CFR

2010-04-01

... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Carbon dioxide absorbent. 868.5300 Section 868...) MEDICAL DEVICES ANESTHESIOLOGY DEVICES Therapeutic Devices § 868.5300 Carbon dioxide absorbent. (a) Identification. A carbon dioxide absorbent is a device intended for medical purposes that consists of an...

21 CFR 868.5300 - Carbon dioxide absorbent.

Code of Federal Regulations, 2014 CFR

2014-04-01

... 21 Food and Drugs 8 2014-04-01 2014-04-01 false Carbon dioxide absorbent. 868.5300 Section 868...) MEDICAL DEVICES ANESTHESIOLOGY DEVICES Therapeutic Devices § 868.5300 Carbon dioxide absorbent. (a) Identification. A carbon dioxide absorbent is a device intended for medical purposes that consists of an...

21 CFR 868.5300 - Carbon dioxide absorbent.

Code of Federal Regulations, 2013 CFR

2013-04-01

... 21 Food and Drugs 8 2013-04-01 2013-04-01 false Carbon dioxide absorbent. 868.5300 Section 868...) MEDICAL DEVICES ANESTHESIOLOGY DEVICES Therapeutic Devices § 868.5300 Carbon dioxide absorbent. (a) Identification. A carbon dioxide absorbent is a device intended for medical purposes that consists of an...

Carbon-Based Materials for Lithium-Ion Batteries, Electrochemical Capacitors, and Their Hybrid Devices.

PubMed

Yao, Fei; Pham, Duy Tho; Lee, Young Hee

2015-07-20

A rapidly developing market for portable electronic devices and hybrid electrical vehicles requires an urgent supply of mature energy-storage systems. As a result, lithium-ion batteries and electrochemical capacitors have lately attracted broad attention. Nevertheless, it is well known that both devices have their own drawbacks. With the fast development of nanoscience and nanotechnology, various structures and materials have been proposed to overcome the deficiencies of both devices to improve their electrochemical performance further. In this Review, electrochemical storage mechanisms based on carbon materials for both lithium-ion batteries and electrochemical capacitors are introduced. Non-faradic processes (electric double-layer capacitance) and faradic reactions (pseudocapacitance and intercalation) are generally explained. Electrochemical performance based on different types of electrolytes is briefly reviewed. Furthermore, impedance behavior based on Nyquist plots is discussed. We demonstrate the influence of cell conductivity, electrode/electrolyte interface, and ion diffusion on impedance performance. We illustrate that relaxation time, which is closely related to ion diffusion, can be extracted from Nyquist plots and compared between lithium-ion batteries and electrochemical capacitors. Finally, recent progress in the design of anodes for lithium-ion batteries, electrochemical capacitors, and their hybrid devices based on carbonaceous materials are reviewed. Challenges and future perspectives are further discussed. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Carbon nanotube polymer composites for photonic devices

NASA Astrophysics Data System (ADS)

Scardaci, V.; Rozhin, A. G.; Hennrich, F.; Milne, W. I.; Ferrari, A. C.

2007-03-01

We report the fabrication of high optical quality single wall carbon nanotube polyvinyl alcohol composites and their application in nanotube based photonic devices. These show a broad absorption of semiconductor tubes centred at ∼1.55 μm, the spectral range of interest for optical communications. The films are used as mode-lockers in an erbium doped fibre laser, achieving ∼700 fs mode-locked pulses. Raman spectroscopy shows no damage after a long time continuous laser operation.

Development of New Photovoltaic Devices Based on Multi Wall Carbon Nanotubes and Nanoparticles

DTIC Science & Technology

2013-03-01

response is registered in all the photon spectral range studied. The new kind of Graetzel-like solar cell device was built without dye and TiO2 , showing...response is registered in all the photon spectral range studied. - The new kind of Graetzel (DSSC, Dye Synthesized Solar Cell ) built without Dye and TiO2 ...an IPCE up to 20%. 15. SUBJECT TERMS EOARD, organic solar cells , photovoltaics, carbon nanotubes 16. SECURITY CLASSIFICATION

Recent advances in molecular electronics based on carbon nanotubes.

PubMed

Bourgoin, Jean-Philippe; Campidelli, Stéphane; Chenevier, Pascale; Derycke, Vincent; Filoramo, Arianna; Goffman, Marcelo F

2010-01-01

Carbon nanotubes (CNTs) have exceptional physical properties that make them one of the most promising building blocks for future nanotechnologies. They may in particular play an important role in the development of innovative electronic devices in the fields of flexible electronics, ultra-high sensitivity sensors, high frequency electronics, opto-electronics, energy sources and nano-electromechanical systems (NEMS). Proofs of concept of several high performance devices already exist, usually at the single device level, but there remain many serious scientific issues to be solved before the viability of such routes can be evaluated. In particular, the main concern regards the controlled synthesis and positioning of nanotubes. In our opinion, truly innovative use of these nano-objects will come from: (i) the combination of some of their complementary physical properties, such as combining their electrical and mechanical properties, (ii) the combination of their properties with additional benefits coming from other molecules grafted on the nanotubes, and (iii) the use of chemically- or bio-directed self-assembly processes to allow the efficient combination of several devices into functional arrays or circuits. In this article, we outline the main issues concerning the development of carbon nanotubes based electronics applications and review our recent results in the field.

A study on carbon nanotube bridge as a electromechanical memory device

NASA Astrophysics Data System (ADS)

Kang, Jeong Won; Ha Lee, Jun; Joo Lee, Hoong; Hwang, Ho Jung

2005-04-01

A nanoelectromechanical (NEM) nanotube random access memory (NRAM) device based on carbon nanotube (CNT) was investigated using atomistic simulations. For the CNT-based NEM memory, the mechanical properties of the CNT-bridge and van der Waals interactions between the CNT-bridge and substrate were very important. The critical amplitude of the CNT-bridge was 16% of the length of the CNT-bridge. As molecular dynamics time increased, the CNT-bridge went to the steady state under the electrostatic force with the damping of the potential and the kinetic energies of the CNT-bridge. The interatomic interaction between the CNT-bridge and substrate, value of the CNT-bridge slack, and damping rate of the CNT-bridge were very important for the operation of the NEM memory device as a nonvolatile memory.

Carbon nanotube array based sensor

DOEpatents

Lee, Christopher L.; Noy, Aleksandr; Swierkowski, Stephan P.; Fisher, Karl A.; Woods, Bruce W.

2005-09-20

A sensor system comprising a first electrode with an array of carbon nanotubes and a second electrode. The first electrode with an array of carbon nanotubes and the second electrode are positioned to produce an air gap between the first electrode with an array of carbon nanotubes and the second electrode. A measuring device is provided for sensing changes in electrical capacitance between the first electrode with an array of carbon nanotubes and the second electrode.

Exploring Carbon Nanotubes for Nanoscale Devices

NASA Technical Reports Server (NTRS)

Han, Jie; Dai; Anantram; Jaffe; Saini, Subhash (Technical Monitor)

1998-01-01

Carbon nanotubes (CNTs) are shown to promise great opportunities in nanoelectronic devices and nanoelectromechanical systems (NEMS) because of their inherent nanoscale sizes, intrinsic electric conductivities, and seamless hexagonal network architectures. I present our collaborative work with Stanford on exploring CNTs for nanodevices in this talk. The electrical property measurements suggest that metallic tubes are quantum wires. Furthermore, two and three terminal CNT junctions have been observed experimentally. We have proposed and studied CNT-based molecular switches and logic devices for future digital electronics. We also have studied CNTs based NEMS inclusing gears, cantilevers, and scanning probe microscopy tips. We investigate both chemistry and physics based aspects of the CNT NEMS. Our results suggest that CNT have ideal stiffness, vibrational frequencies, Q-factors, geometry-dependent electric conductivities, and the highest chemical and mechanical stabilities for the NEMS. The use of CNT SPM tips for nanolithography is presented for demonstration of the advantages of the CNT NEMS.

Carbon Redox-Polymer-Gel Hybrid Supercapacitors.

PubMed

Vlad, A; Singh, N; Melinte, S; Gohy, J-F; Ajayan, P M

2016-02-26

Energy storage devices that provide high specific power without compromising on specific energy are highly desirable for many electric-powered applications. Here, we demonstrate that polymer organic radical gel materials support fast bulk-redox charge storage, commensurate to surface double layer ion exchange at carbon electrodes. When integrated with a carbon-based electrical double layer capacitor, nearly ideal electrode properties such as high electrical and ionic conductivity, fast bulk redox and surface charge storage as well as excellent cycling stability are attained. Such hybrid carbon redox-polymer-gel electrodes support unprecedented discharge rate of 1,000C with 50% of the nominal capacity delivered in less than 2 seconds. Devices made with such electrodes hold the potential for battery-scale energy storage while attaining supercapacitor-like power performances.

21 CFR 868.5310 - Carbon dioxide absorber.

Code of Federal Regulations, 2010 CFR

2010-04-01

... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Carbon dioxide absorber. 868.5310 Section 868.5310...) MEDICAL DEVICES ANESTHESIOLOGY DEVICES Therapeutic Devices § 868.5310 Carbon dioxide absorber. (a) Identification. A carbon dioxide absorber is a device that is intended for medical purposes and that is used in a...

21 CFR 868.5310 - Carbon dioxide absorber.

Code of Federal Regulations, 2013 CFR

2013-04-01

... 21 Food and Drugs 8 2013-04-01 2013-04-01 false Carbon dioxide absorber. 868.5310 Section 868.5310...) MEDICAL DEVICES ANESTHESIOLOGY DEVICES Therapeutic Devices § 868.5310 Carbon dioxide absorber. (a) Identification. A carbon dioxide absorber is a device that is intended for medical purposes and that is used in a...

21 CFR 868.5310 - Carbon dioxide absorber.

Code of Federal Regulations, 2014 CFR

2014-04-01

... 21 Food and Drugs 8 2014-04-01 2014-04-01 false Carbon dioxide absorber. 868.5310 Section 868.5310...) MEDICAL DEVICES ANESTHESIOLOGY DEVICES Therapeutic Devices § 868.5310 Carbon dioxide absorber. (a) Identification. A carbon dioxide absorber is a device that is intended for medical purposes and that is used in a...

21 CFR 868.5310 - Carbon dioxide absorber.

Code of Federal Regulations, 2012 CFR

2012-04-01

... 21 Food and Drugs 8 2012-04-01 2012-04-01 false Carbon dioxide absorber. 868.5310 Section 868.5310 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES ANESTHESIOLOGY DEVICES Therapeutic Devices § 868.5310 Carbon dioxide absorber. (a) Identification. A carbon dioxide absorber is a devic...

21 CFR 868.5310 - Carbon dioxide absorber.

Code of Federal Regulations, 2011 CFR

2011-04-01

... 21 Food and Drugs 8 2011-04-01 2011-04-01 false Carbon dioxide absorber. 868.5310 Section 868.5310 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES ANESTHESIOLOGY DEVICES Therapeutic Devices § 868.5310 Carbon dioxide absorber. (a) Identification. A carbon dioxide absorber is a devic...

Three-dimensional paper-based electrochemiluminescence immunodevice for multiplexed measurement of biomarkers and point-of-care testing.

PubMed

Ge, Lei; Yan, Jixian; Song, Xianrang; Yan, Mei; Ge, Shenguang; Yu, Jinghua

2012-02-01

In this work, electrochemiluminescence (ECL) immunoassay was introduced into the recently proposed microfluidic paper-based analytical device (μPADs) based on directly screen-printed electrodes on paper for the very first time. The screen-printed paper-electrodes will be more important for further development of this paper-based ECL device in simple, low-cost and disposable application than commercialized ones. To further perform high-performance, high-throughput, simple and inexpensive ECL immunoassay on μPAD for point-of-care testing, a wax-patterned three-dimensional (3D) paper-based ECL device was demonstrated for the very first time. In this 3D paper-based ECL device, eight carbon working electrodes including their conductive pads were screen-printed on a piece of square paper and shared the same Ag/AgCl reference and carbon counter electrodes on another piece of square paper after stacking. Using typical tris-(bipyridine)-ruthenium (Ⅱ) - tri-n-propylamine ECL system, the application test of this 3D paper-based ECL device was performed through the diagnosis of four tumor markers in real clinical serum samples. With the aid of a facile device-holder and a section-switch assembled on the analyzer, eight working electrodes were sequentially placed into the circuit to trigger the ECL reaction in the sweeping range from 0.5 to 1.1 V at room temperature. In addition, this 3D paper-based ECL device can be easily integrated and combined with the recently emerging paper electronics to further develop simple, sensitive, low-cost, disposable and portable μPAD for point-of-care testing, public health and environmental monitoring in remote regions, developing or developed countries. Copyright © 2011 Elsevier Ltd. All rights reserved.

Recent progress of carbon nanotube field emitters and their application.

PubMed

Seelaboyina, Raghunandan; Choi, Wonbong

2007-01-01

The potential of utilizing carbon nanotube field emission properties is an attractive feature for future vacuum electronic devices including: high power microwave, miniature x-ray, backlight for liquid crystal displays and flat panel displays. Their high emission current, nano scale geometry, chemical inertness and low threshold voltage for emission are attractive features for the field emission applications. In this paper we review the recent developments of carbon nanotube field emitters and their device applications. We also discuss the latest results on field emission current amplification achieved with an electron multiplier microchannel plate, and emission performance of multistage field emitter based on oxide nanowire operated in poor vacuum.

Solid state carbon nanotube device for controllable trion electroluminescence emission

NASA Astrophysics Data System (ADS)

Liang, Shuang; Ma, Ze; Wei, Nan; Liu, Huaping; Wang, Sheng; Peng, Lian-Mao

2016-03-01

Semiconducting carbon nanotubes (CNTs) have a direct chirality-dependent bandgap and reduced dimensionality-related quantum confinement effects, which are closely related to the performance of optoelectronic devices. Here, taking advantage of the large energy separations between neutral singlet excitons and charged excitons, i.e. trions in CNTs, we have achieved for the first time all trion electroluminescence (EL) emission from chirality-sorted (8,3) and (8,4) CNT-based solid state devices. We showed that strong trion emission can be obtained as a result of localized impact excitation and electrically injected holes, with an estimated efficiency of ~5 × 10-4 photons per injected hole. The importance of contact-controlled carrier injection (including symmetric and asymmetric contact configurations) and EL spectral stability for gradually increasing bias were also investigated. The realization of electrically induced pure trion emission opens up a new opportunity for CNT film-based optoelectronic devices, providing a new degree of freedom in controlling the devices to extend potential applications in spin or magnetic optoelectronics fields.Semiconducting carbon nanotubes (CNTs) have a direct chirality-dependent bandgap and reduced dimensionality-related quantum confinement effects, which are closely related to the performance of optoelectronic devices. Here, taking advantage of the large energy separations between neutral singlet excitons and charged excitons, i.e. trions in CNTs, we have achieved for the first time all trion electroluminescence (EL) emission from chirality-sorted (8,3) and (8,4) CNT-based solid state devices. We showed that strong trion emission can be obtained as a result of localized impact excitation and electrically injected holes, with an estimated efficiency of ~5 × 10-4 photons per injected hole. The importance of contact-controlled carrier injection (including symmetric and asymmetric contact configurations) and EL spectral stability for gradually increasing bias were also investigated. The realization of electrically induced pure trion emission opens up a new opportunity for CNT film-based optoelectronic devices, providing a new degree of freedom in controlling the devices to extend potential applications in spin or magnetic optoelectronics fields. Electronic supplementary information (ESI) available. See DOI: 10.1039/c5nr07468a

AC-conductance and capacitance measurements for ethanol vapor detection using carbon nanotube-polyvinyl alcohol composite based devices.

PubMed

Greenshields, Márcia W C C; Meruvia, Michelle S; Hümmelgen, Ivo A; Coville, Neil J; Mhlanga, Sabelo D; Ceragioli, Helder J; Quispe, Jose C Rojas; Baranauskas, Vitor

2011-03-01

We report the preparation of inexpensive ethanol sensor devices using multiwalled carbon nanotube-polyvinyl alcohol composite films deposited onto interdigitated electrodes patterned on phenolite substrates. We investigate the frequency dependent response of the device conductance and capacitance showing that higher sensitivity is obtained at higher frequency if the conductance is used as sensing parameter. In the case of capacitance measurements, higher sensitivity is obtained at low frequency. Ethanol detection at a concentration of 300 ppm in air is demonstrated. More than 80% of the sensor conductance and capacitance variation response occurs in less than 20 s.

Rotating carbon nanotube membrane filter for water desalination

NASA Astrophysics Data System (ADS)

Tu, Qingsong; Yang, Qiang; Wang, Hualin; Li, Shaofan

2016-05-01

We have designed a porous nanofluidic desalination device, a rotating carbon nanotube membrane filter (RCNT-MF), for the reverse osmosis desalination that can turn salt water into fresh water. The concept as well as design strategy of RCNT-MF is modeled, and demonstrated by using molecular dynamics simulation. It has been shown that the RCNT-MF device may significantly improve desalination efficiency by combining the centrifugal force propelled reverse osmosis process and the porous CNT-based fine scale selective separation technology.

Rotating carbon nanotube membrane filter for water desalination

PubMed Central

Tu, Qingsong; Yang, Qiang; Wang, Hualin; Li, Shaofan

2016-01-01

We have designed a porous nanofluidic desalination device, a rotating carbon nanotube membrane filter (RCNT-MF), for the reverse osmosis desalination that can turn salt water into fresh water. The concept as well as design strategy of RCNT-MF is modeled, and demonstrated by using molecular dynamics simulation. It has been shown that the RCNT-MF device may significantly improve desalination efficiency by combining the centrifugal force propelled reverse osmosis process and the porous CNT-based fine scale selective separation technology. PMID:27188982

Dry-Deposited Transparent Carbon Nanotube Film as Front Electrode in Colloidal Quantum Dot Solar Cells.

PubMed

Zhang, Xiaoliang; Aitola, Kerttu; Hägglund, Carl; Kaskela, Antti; Johansson, Malin B; Sveinbjörnsson, Kári; Kauppinen, Esko I; Johansson, Erik M J

2017-01-20

Single-walled carbon nanotubes (SWCNTs) show great potential as an alternative material for front electrodes in photovoltaic applications, especially for flexible devices. In this work, a press-transferred transparent SWCNT film was utilized as front electrode for colloidal quantum dot solar cells (CQDSCs). The solar cells were fabricated on both glass and flexible substrates, and maximum power conversion efficiencies of 5.5 and 5.6 %, respectively, were achieved, which corresponds to 90 and 92 % of an indium-doped tin oxide (ITO)-based device (6.1 %). The SWCNTs are therefore a very good alternative to the ITO-based electrodes especially for flexible solar cells. The optical electric field distribution and optical losses within the devices were simulated theoretically and the results agree with the experimental results. With the optical simulations that were performed it may also be possible to enhance the photovoltaic performance of SWCNT-based solar cells even further by optimizing the device configuration or by using additional optical active layers, thus reducing light reflection of the device and increasing light absorption in the quantum dot layer. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

Flexible carbon micro-supercapacitors prepared by direct cw-laser writing

NASA Astrophysics Data System (ADS)

Cai, Jinguang; Watanabe, Akira

2016-03-01

Micro-/nano-scale power supply units with high energy and high power densities are critical components for the development of compact miniaturized portable electronic devices. Supercapacitors have attracted many research attentions due to their high power density, robust cycle performance, pollution-free operation, and maintenance-free features. Besides, the properties of small size, light weight, and flexibility are also required. On-chip microsupercapacitors (MSCs) have the potential acting as power supply units in portable devices, due to their simplified packaging processes and compatibility to the integrated circuits. However, the fabrication methods and materials should be cost-effective, scalable, and compatible to current electronic industry. Carbon materials own high specific surface areas, electrochemical stability, and high electrical conductivity, which are critical parameters for high-power supercapacitors. Moreover, the high mechanical tolerance makes them good candidates for flexible wearable devices. Therefore, MSCs based on carbon materials would satisfy the requirements of portable electronics. In this work, we demonstrated the fabrication of carbon MSCs by laser direct writing on commercial polyimide sheets in Ar with lowcost semiconductor cw-laser with a wavelength of 405nm. The obtained structures are macro-nanostructures comprising graphitized and amorphous carbon with relatively smooth surfaces and low resistance, in compared with the structures obtained by laser writing in air. As-prepared micro-supercapacitors show a high capacitance of about 14.9 mF/cm2 at a scanning rate of 10 mV/s, which is comparable to the reported highest capacitance of carbon-based supercapacitors fabricated by pulse-laser writing.

Activated carbon and single-walled carbon nanotube based electrochemical capacitor in 1 M LiPF{sub 6} electrolyte

DOE Office of Scientific and Technical Information (OSTI.GOV)

Azam, M.A., E-mail: asyadi@utem.edu.my; Jantan, N.H.; Dorah, N.

2015-09-15

Highlights: • Activated carbon and single-walled CNT based electrochemical capacitor. • Electrochemical analysis by means of CV, charge/discharge and impedance. • 1 M LiPF{sub 6} non-aqueous solution as an electrolyte. • AC/SWCNT electrode exhibits a maximum capacitance of 60.97 F g{sup −1}. - Abstract: Carbon nanotubes have been extensively studied because of their wide range of potential application such as in nanoscale electric circuits, textiles, transportation, health, and the environment. Carbon nanotubes feature extraordinary properties, such as electrical conductivities higher than those of copper, hardness and thermal conductivity higher than those of diamond, and strength surpassing that of steel, amongmore » others. This research focuses on the fabrication of an energy storage device, namely, an electrochemical capacitor, by using carbon materials, i.e., activated carbon and single-walled carbon nanotubes, of a specific weight ratio as electrode materials. The electrolyte functioning as an ion carrier is 1 M lithium hexafluorophosphate. Variations in the electrochemical performance of the device, including its capacitance, charge/discharge characteristics, and impedance, are reported in this paper. The electrode proposed in this work exhibits a maximum capacitance of 60.97 F g{sup −1} at a scan rate of 1 mV s{sup −1}.« less

Mouldable all-carbon integrated circuits

NASA Astrophysics Data System (ADS)

Sun, Dong-Ming; Timmermans, Marina Y.; Kaskela, Antti; Nasibulin, Albert G.; Kishimoto, Shigeru; Mizutani, Takashi; Kauppinen, Esko I.; Ohno, Yutaka

2013-08-01

A variety of plastic products, ranging from those for daily necessities to electronics products and medical devices, are produced by moulding techniques. The incorporation of electronic circuits into various plastic products is limited by the brittle nature of silicon wafers. Here we report mouldable integrated circuits for the first time. The devices are composed entirely of carbon-based materials, that is, their active channels and passive elements are all fabricated from stretchable and thermostable assemblies of carbon nanotubes, with plastic polymer dielectric layers and substrates. The all-carbon thin-film transistors exhibit a mobility of 1,027cm2V-1s-1 and an ON/OFF ratio of 105. The devices also exhibit extreme biaxial stretchability of up to 18% when subjected to thermopressure forming. We demonstrate functional integrated circuits that can be moulded into a three-dimensional dome. Such mouldable electronics open new possibilities by allowing for the addition of electronic/plastic-like functionalities to plastic/electronic products, improving their designability.

Mouldable all-carbon integrated circuits.

PubMed

Sun, Dong-Ming; Timmermans, Marina Y; Kaskela, Antti; Nasibulin, Albert G; Kishimoto, Shigeru; Mizutani, Takashi; Kauppinen, Esko I; Ohno, Yutaka

2013-01-01

A variety of plastic products, ranging from those for daily necessities to electronics products and medical devices, are produced by moulding techniques. The incorporation of electronic circuits into various plastic products is limited by the brittle nature of silicon wafers. Here we report mouldable integrated circuits for the first time. The devices are composed entirely of carbon-based materials, that is, their active channels and passive elements are all fabricated from stretchable and thermostable assemblies of carbon nanotubes, with plastic polymer dielectric layers and substrates. The all-carbon thin-film transistors exhibit a mobility of 1,027 cm(2) V(-1) s(-1) and an ON/OFF ratio of 10(5). The devices also exhibit extreme biaxial stretchability of up to 18% when subjected to thermopressure forming. We demonstrate functional integrated circuits that can be moulded into a three-dimensional dome. Such mouldable electronics open new possibilities by allowing for the addition of electronic/plastic-like functionalities to plastic/electronic products, improving their designability.

Shape‐Controlled, Self‐Wrapped Carbon Nanotube 3D Electronics

PubMed Central

Wang, Huiliang; Wang, Yanming; Tee, Benjamin C.‐K.; Kim, Kwanpyo; Lopez, Jeffrey; Cai, Wei

2015-01-01

The mechanical flexibility and structural softness of ultrathin devices based on organic thin films and low‐dimensional nanomaterials have enabled a wide range of applications including flexible display, artificial skin, and health monitoring devices. However, both living systems and inanimate systems that are encountered in daily lives are all 3D. It is therefore desirable to either create freestanding electronics in a 3D form or to incorporate electronics onto 3D objects. Here, a technique is reported to utilize shape‐memory polymers together with carbon nanotube flexible electronics to achieve this goal. Temperature‐assisted shape control of these freestanding electronics in a programmable manner is demonstrated, with theoretical analysis for understanding the shape evolution. The shape control process can be executed with prepatterned heaters, desirable for 3D shape formation in an enclosed environment. The incorporation of carbon nanotube transistors, gas sensors, temperature sensors, and memory devices that are capable of self‐wrapping onto any irregular shaped‐objects without degradations in device performance is demonstrated. PMID:27980972

Research Progress in MnO2 -Carbon Based Supercapacitor Electrode Materials.

PubMed

Zhang, Qun-Zheng; Zhang, Dian; Miao, Zong-Cheng; Zhang, Xun-Li; Chou, Shu-Lei

2018-04-30

With the serious impact of fossil fuels on the environment and the rapid development of the global economy, the development of clean and usable energy storage devices has become one of the most important themes of sustainable development in the world today. Supercapacitors are a new type of green energy storage device, with high power density, long cycle life, wide temperature range, and both economic and environmental advantages. In many industries, they have enormous application prospects. Electrode materials are an important factor affecting the performance of supercapacitors. MnO 2 -based materials are widely investigated for supercapacitors because of their high theoretical capacitance, good chemical stability, low cost, and environmental friendliness. To achieve high specific capacitance and high rate capability, the current best solution is to use MnO 2 and carbon composite materials. Herein, MnO 2 -carbon composite as supercapacitor electrode materials is reviewed including the synthesis method and research status in recent years. Finally, the challenges and future development directions of an MnO 2 -carbon based supercapacitor are summarized. © 2018 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Functional Carbon Nanocomposite, Optoelectronic, and Catalytic Coatings

NASA Astrophysics Data System (ADS)

Liang, Yu Teng

Over the past couple decades, fundamental research into carbon nanomaterials has produced a steady stream of groundbreaking physical science. Their record setting mechanical strength, chemical stability, and optoelectronic performance have fueled many optimistic claims regarding the breadth and pace of carbon nanotube and graphene integration. However, present synthetic, processing, and economic constraints have precluded these materials from many practical device applications. To overcome these limitations, novel synthetic techniques, processing methodologies, device geometries, and mechanistic insight were developed in this dissertation. The resulting advancements in material production and composite device performance have brought carbon nanomaterials ever closer to commercial implementation. For improved materials processing, vacuum co-deposition was first demonstrated as viable technique for forming carbon nanocomposite films without property distorting covalent modifications. Co-deposited nanoparticle, carbon nanotube, and graphene composite films enabled rapid device prototyping and compositional optimization. Cellulosic polymer stabilizers were then shown to be highly effective carbon nanomaterial dispersants, improving graphene production yields by two orders of magnitude in common organic solvents. By exploiting polarity interactions, iterative solvent exchange was used to further increase carbon nanomaterial dispersion concentrations by an additional order of magnitude, yielding concentrated inks. On top of their low causticity, these cellulosic nanomaterial inks have highly tunable viscosities, excellent film forming capacity, and outstanding thermal stability. These processing characteristics enable the efficient scaling of carbon nanomaterial coatings and device production using existing roll-to-roll fabrication techniques. Utilizing these process improvements, high-performance gas sensing, energy storage, transparent conductor, and photocatalytic coatings have been demonstrated. In particular, co-deposited platinum, silicon, and carbon nanomaterial films were fashioned into electronic hydrogen gas sensors, cost efficient dye sensitized solar cell electrodes, and high capacity lithium ion battery anodes. Furthermore, concentrated graphene inks were coated to form aligned graphene-polymer nanocomposites and outstanding carbon nanotube-graphene hybrid semitransparent electrical conductors. Nanocomposite graphene-titanium dioxide catalysts produced from these cellulosic inks have low covalent defect densities and were shown to be approximately two and seven times more active than those based on reduced graphene oxide in photo-oxidation and photo-reduction reactions, respectively. Using a broad range of material characterization techniques, mechanistic insight was obtained using composite photocatalysts fabricated from well defined nanomaterials. For instance, optical spectroscopy and electronic measurements revealed a direct correlation between graphene charge transport performance and composite photochemical activity. Moreover, investigations into multidimensional composites based on 1D carbon nanotubes, 2D graphene, and 2D titanium dioxide nanosheets generated additional mechanistic insight for extending photocatalytic spectral response and increasing reaction specificity. Together, these results demonstrate the versatility of vacuum co-deposition and cellulosic nanomaterial inks for fabricating carbon nanocomposite optoelectronic and energy conversion coatings.

Carbon Nanotubes versus Graphene as Flexible Transparent Electrodes in Inverted Perovskite Solar Cells.

PubMed

Jeon, Il; Yoon, Jungjin; Ahn, Namyoung; Atwa, Mohamed; Delacou, Clement; Anisimov, Anton; Kauppinen, Esko I; Choi, Mansoo; Maruyama, Shigeo; Matsuo, Yutaka

2017-11-02

Transparent carbon electrodes, carbon nanotubes, and graphene were used as the bottom electrode in flexible inverted perovskite solar cells. Their photovoltaic performance and mechanical resilience were compared and analyzed using various techniques. Whereas a conventional inverted perovskite solar cells using indium tin oxide showed a power conversion efficiency of 17.8%, the carbon nanotube- and graphene-based cells showed efficiencies of 12.8% and 14.2%, respectively. An established MoO 3 doping was used for  carbon electrode-based devices. The difference in the photovoltaic performance between the carbon nanotube- and graphene-based cells was due to the difference in morphology and transmittance. Raman spectroscopy, and cyclic flexural testing revealed that the graphene-based cells were more susceptible to strain than the carbon nanotube-based cells, though the difference was marginal. Overall, despite higher performance, the transfer step for graphene has lower reproducibility. Thus, the development of better graphene transfer methods would help maximize the current capacity of graphene-based cells.

Carbon nanotube chemistry and assembly for electronic devices

NASA Astrophysics Data System (ADS)

Derycke, Vincent; Auvray, Stéphane; Borghetti, Julien; Chung, Chia-Ling; Lefèvre, Roland; Lopez-Bezanilla, Alejandro; Nguyen, Khoa; Robert, Gaël; Schmidt, Gregory; Anghel, Costin; Chimot, Nicolas; Lyonnais, Sébastien; Streiff, Stéphane; Campidelli, Stéphane; Chenevier, Pascale; Filoramo, Arianna; Goffman, Marcelo F.; Goux-Capes, Laurence; Latil, Sylvain; Blase, Xavier; Triozon, François; Roche, Stephan; Bourgoin, Jean-Philippe

2009-05-01

Carbon nanotubes (CNTs) have exceptional physical properties that make them one of the most promising building blocks for future nanotechnologies. They may in particular play an important role in the development of innovative electronic devices in the fields of flexible electronics, ultra-high sensitivity sensors, high frequency electronics, opto-electronics, energy sources and nano-electromechanical systems (NEMS). Proofs of concept of several high performance devices already exist, usually at the single device level, but there remain many serious scientific issues to be solved before the viability of such routes can be evaluated. In particular, the main concern regards the controlled synthesis and positioning of nanotubes. In our opinion, truly innovative use of these nano-objects will come from: (i) the combination of some of their complementary physical properties, such as combining their electrical and mechanical properties; (ii) the combination of their properties with additional benefits coming from other molecules grafted on the nanotubes (this route being particularly relevant for gas- and bio-sensors, opto-electronic devices and energy sources); and (iii) the use of chemically- or bio-directed self-assembly processes to allow the efficient combination of several devices into functional arrays or circuits. In this article, we review our recent results concerning nanotube chemistry and assembly and their use to develop electronic devices. In particular, we present carbon nanotube field effect transistors and their chemical optimization, high frequency nanotube transistors, nanotube-based opto-electronic devices with memory capabilities and nanotube-based nano-electromechanical systems (NEMS). The impact of chemical functionalization on the electronic properties of CNTs is analyzed on the basis of theoretical calculations. To cite this article: V. Derycke et al., C. R. Physique 10 (2009).

Paper-based electroanalytical devices for in situ determination of salicylic acid in living tomato leaves.

PubMed

Sun, Li-Jun; Feng, Qiu-Mei; Yan, Yong-Feng; Pan, Zhong-Qin; Li, Xiao-Hui; Song, Feng-Ming; Yang, Haibing; Xu, Jing-Juan; Bao, Ning; Gu, Hai-Ying

2014-10-15

Detection of phytohormones in situ has gained significant attention due to their critical roles in regulating developmental processes and signaling for defenses in plants at low concentration. As one type of plant hormones, salicylic acid has recently been found to be one of pivotal signal molecules for physiological behaviors of plants. Here we report the application of paper-based electroanalytical devices for sensitively in situ detection of salicylic acid in tomato leaves with the sample volume of several microliters. Specifically, disposable working electrodes were fabricated by coating carbon tape with the mixture of multiwall carbon nanotubes and nafion. We observed that the treatment of the modified carbon tape electrodes with oxygen plasma could significantly improve electrochemical responses of salicylic acid. The tomato leaves had a punched hole of 1.5mm diameter to release salicylic acid with minor influence on continuous growth of tomatoes. By incorporating the tomato leaf with the paper-based analytical device, we were able to perform in situ determination of salicylic acid based on its electrocatalytic oxidation. Our experimental results demonstrated that the amounts of salicylic acid differed statistically in normal, phytoene desaturase (PDS) gene silent and diseased (infected by Botrytis cinerea) tomato leaves. By quantifying salicylic acid at the level of several nanograms in situ, the simple paper-based electroanalytical devices could potentially facilitate the study of defense mechanism of plants under biotic and abiotic stresses. This study might also provide a sensitive method with spatiotemporal resolution for mapping of chemicals released from living organisms. Copyright © 2014 Elsevier B.V. All rights reserved.

Performance of carbon-carbon supercapacitors based on organic, aqueous and ionic liquid electrolytes

NASA Astrophysics Data System (ADS)

Lewandowski, Andrzej; Olejniczak, Angelika; Galinski, Maciej; Stepniak, Izabela

Properties of capacitors working with the same carbon electrodes (activated carbon cloth) and three types of electrolytes: aqueous, organic and ionic liquids were compared. Capacitors filled with ionic liquids worked at a potential difference of 3.5 V, their solutions in AN and PC were charged up to the potential difference of 3 V, classical organic systems to 2.5 V and aqueous to 1 V. Cyclic voltammetry, galvanostatic charging/discharging and impedance spectroscopy were used to characterize these capacitors. The highest specific energy was recorded for the device working with ionic liquids, while the highest power is characteristic for the device filled with aqueous H 2SO 4 electrolyte. Aqueous electrolytes led to energy density an order of magnitude lower in comparison to that characteristic of ionic liquids.

Carbon Redox-Polymer-Gel Hybrid Supercapacitors

PubMed Central

Vlad, A.; Singh, N.; Melinte, S.; Gohy, J.-F.; Ajayan, P.M.

2016-01-01

Energy storage devices that provide high specific power without compromising on specific energy are highly desirable for many electric-powered applications. Here, we demonstrate that polymer organic radical gel materials support fast bulk-redox charge storage, commensurate to surface double layer ion exchange at carbon electrodes. When integrated with a carbon-based electrical double layer capacitor, nearly ideal electrode properties such as high electrical and ionic conductivity, fast bulk redox and surface charge storage as well as excellent cycling stability are attained. Such hybrid carbon redox-polymer-gel electrodes support unprecedented discharge rate of 1,000C with 50% of the nominal capacity delivered in less than 2 seconds. Devices made with such electrodes hold the potential for battery-scale energy storage while attaining supercapacitor-like power performances. PMID:26917470

Current-induced changes of migration energy barriers in graphene and carbon nanotubes.

PubMed

Obodo, J T; Rungger, I; Sanvito, S; Schwingenschlögl, U

2016-05-21

An electron current can move atoms in a nanoscale device with important consequences for the device operation and breakdown. We perform first principles calculations aimed at evaluating the possibility of changing the energy barriers for atom migration in carbon-based systems. In particular, we consider the migration of adatoms and defects in graphene and carbon nanotubes. Although the current-induced forces are large for both the systems, in graphene the force component along the migration path is small and therefore the barrier height is little affected by the current flow. In contrast, the same barrier is significantly reduced in carbon nanotubes as the current increases. Our work also provides a real-system numerical demonstration that current-induced forces within density functional theory are non-conservative.

Microwave Plasma Based Single-Step Method for Generation of Carbon Nanostructures

DTIC Science & Technology

2013-07-01

Técnico, Technical University of Lisbon, Portugal 2 Mechanical and Aerospace Engeneering , Naval Postgraduate School, Monterey, CA 93943, U.S.A...Plasma environments constitute powerful tools in materials science due to their operation as thermal and chemical reactors. A microwave, atmospheric...applications include electronic devices, transparent conductive films, mechanical devices, chemical sensors, spintronic devices. Moreover, it shows enormous

Main principles of passive devices based on graphene and carbon films in microwave-THz frequency range

NASA Astrophysics Data System (ADS)

Kuzhir, Polina P.; Paddubskaya, Alesia G.; Volynets, Nadezhda I.; Batrakov, Konstantin G.; Kaplas, Tommi; Lamberti, Patrizia; Kotsilkova, Rumiana; Lambin, Philippe

2017-07-01

The ability of thin conductive films, including graphene, pyrolytic carbon (PyC), graphitic PyC (GrPyC), graphene with graphitic islands (GrI), glassy carbon (GC), and sandwich structures made of all these materials separated by polymer slabs to absorb electromagnetic radiation in microwave-THz frequency range, is discussed. The main physical principles making a basis for high absorption ability of these heterostructures are explained both in the language of electromagnetic theory and using representation of equivalent electrical circuits. The idea of using carbonaceous thin films as the main working elements of passive radiofrequency (RF) devices, such as shields, filters, polarizers, collimators, is proposed theoretically and proved experimentally. The important advantage of PyC, GrI, GrPyC, and GC is that, in contrast to graphene, they either can be easily deposited onto a dielectric substrate or are strong enough to allow their transfer from the catalytic substrate without a shuttle polymer layer. This opens a new avenue toward the development of a scalable protocol for cost-efficient production of ultralight electromagnetic shields that can be transferred to commercial applications. A robust design via finite-element method and design of experiment for RF devices based on carbon/graphene films and sandwiches is also discussed in the context of virtual prototyping.

Three-Dimensional Flexible Complementary Metal-Oxide-Semiconductor Logic Circuits Based On Two-Layer Stacks of Single-Walled Carbon Nanotube Networks.

PubMed

Zhao, Yudan; Li, Qunqing; Xiao, Xiaoyang; Li, Guanhong; Jin, Yuanhao; Jiang, Kaili; Wang, Jiaping; Fan, Shoushan

2016-02-23

We have proposed and fabricated stable and repeatable, flexible, single-walled carbon nanotube (SWCNT) thin film transistor (TFT) complementary metal-oxide-semiconductor (CMOS) integrated circuits based on a three-dimensional (3D) structure. Two layers of SWCNT-TFT devices were stacked, where one layer served as n-type devices and the other one served as p-type devices. On the basis of this method, it is able to save at least half of the area required to construct an inverter and make large-scale and high-density integrated CMOS circuits easier to design and manufacture. The 3D flexible CMOS inverter gain can be as high as 40, and the total noise margin is more than 95%. Moreover, the input and output voltage of the inverter are exactly matched for cascading. 3D flexible CMOS NOR, NAND logic gates, and 15-stage ring oscillators were fabricated on PI substrates with high performance as well. Stable electrical properties of these circuits can be obtained with bending radii as small as 3.16 mm, which shows that such a 3D structure is a reliable architecture and suitable for carbon nanotube electrical applications in complex flexible and wearable electronic devices.

Quantum transport properties of carbon nanotube field-effect transistors with electron-phonon coupling

NASA Astrophysics Data System (ADS)

Ishii, Hiroyuki; Kobayashi, Nobuhiko; Hirose, Kenji

2007-11-01

We investigated the electron-phonon coupling effects on the electronic transport properties of metallic (5,5)- and semiconducting (10,0)-carbon nanotube devices. We calculated the conductance and mobility of the carbon nanotubes with micron-order lengths at room temperature, using the time-dependent wave-packet approach based on the Kubo-Greenwood formula within a tight-binding approximation. We investigated the scattering effects of both longitudinal acoustic and optical phonon modes on the transport properties. The electron-optical phonon coupling decreases the conductance around the Fermi energy for the metallic carbon nanotubes, while the conductance of semiconductor nanotubes is decreased around the band edges by the acoustic phonons. Furthermore, we studied the Schottky-barrier effects on the mobility of the semiconducting carbon nanotube field-effect transistors for various gate voltages. We clarified how the electron mobilities of the devices are changed by the acoustic phonon.

Carbon Nanotube Devices Engineered by Atomic Force Microscopy

NASA Astrophysics Data System (ADS)

Prisbrey, Landon

This dissertation explores the engineering of carbon nanotube electronic devices using atomic force microscopy (AFM) based techniques. A possible application for such devices is an electronic interface with individual biological molecules. This single molecule biosensing application is explored both experimentally and with computational modeling. Scanning probe microscopy techniques, such as AFM, are ideal to study nanoscale electronics. These techniques employ a probe which is raster scanned above a sample while measuring probe-surface interactions as a function of position. In addition to topographical and electrostatic/magnetic surface characterization, the probe may also be used as a tool to manipulate and engineer at the nanoscale. Nanoelectronic devices built from carbon nanotubes exhibit many exciting properties including one-dimensional electron transport. A natural consequence of onedimensional transport is that a single perturbation along the conduction channel can have extremely large effects on the device's transport characteristics. This property may be exploited to produce electronic sensors with single-molecule resolution. Here we use AFM-based engineering to fabricate atomic-sized transistors from carbon nanotube network devices. This is done through the incorporation of point defects into the carbon nanotube sidewall using voltage pulses from an AFM probe. We find that the incorporation of an oxidative defect leads to a variety of possible electrical signatures including sudden switching events, resonant scattering, and breaking of the symmetry between electron and hole transport. We discuss the relationship between these different electronic signatures and the chemical structure/charge state of the defect. Tunneling through a defect-induced Coulomb barrier is modeled with numerical Verlet integration of Schrodinger's equation and compared with experimental results. Atomic-sized transistors are ideal for single-molecule applications due to their sensitivity to electric fields with very small detection volumes. In this work we demonstrate these devices as single-molecule sensors to detect individual N-(3-Dimethylaminopropyl)- N'-ethylcarbodiimide (EDC) molecules in an aqueous environment. An exciting application of these sensors is to study individual macromolecules participating in biological reactions, or undergoing conformational change. However, it is unknown whether the associated electrostatic signals exceed detection limits. We report calculations which reveal that enzymatic processes, such as substrate binding and internal protein dynamics, are detectable at the single-molecule level using existing atomic-sized transistors. Finally, we demonstrate the use of AFM-based engineering to control the function of nanoelectronic devices without creating a point defect in the sidewall of the nanotube. With a biased AFM probe we write charge patterns on a silicon dioxide surface in close proximity to a carbon nanotube device. The written charge induces image charges in the nearby electronics, and can modulate the Fermi level in a nanotube by +/-1 eV. We use this technique to induce a spatially controlled doping charge pattern in the conduction channel, and thereby reconfigure a field-effect transistor into a pn junction. Other simple charge patterns could be used to create other devices. The doping charge persists for days and can be erased and rewritten, offering a new tool for prototyping nanodevices and optimizing electrostatic doping profiles.

Applications for alliform carbon

DOEpatents

Gogotsi, Yury; Mochalin, Vadym; McDonough, IV, John Kenneth; Simon, Patrice; Taberna, Pierre Louis

2017-02-21

This invention relates to novel applications for alliform carbon, useful in conductors and energy storage devices, including electrical double layer capacitor devices and articles incorporating such conductors and devices. Said alliform carbon particles are in the range of 2 to about 20 percent by weight, relative to the weight of the entire electrode. Said novel applications include supercapacitors and associated electrode devices, batteries, bandages and wound healing, and thin-film devices, including display devices.

Carbon Nanotube Electrode Arrays For Enhanced Chemical and Biological Sensing

NASA Technical Reports Server (NTRS)

Han, Jie

2003-01-01

Applications of carbon nanotubes for ultra-sensitive electrical sensing of chemical and biological species have been a major focus in NASA Ames Center for Nanotechnology. Great progress has been made toward controlled growth and chemical functionalization of vertically aligned carbon nanotube arrays and integration into micro-fabricated chip devices. Carbon nanotube electrode arrays devices have been used for sub-attomole detection of DNA molecules. Interdigitated carbon nanotubes arrays devices have been applied to sub ppb (part per billion) level chemical sensing for many molecules at room temperature. Stability and reliability have also been addressed in our device development. These results show order of magnitude improvement in device performance, size and power consumption as compared to micro devices, promising applications of carbon nanotube electrode arrays for clinical molecular diagnostics, personal medical testing and monitoring, and environmental monitoring.

Paintable Carbon-Based Perovskite Solar Cells with Engineered Perovskite/Carbon Interface Using Carbon Nanotubes Dripping Method.

PubMed

Ryu, Jaehoon; Lee, Kisu; Yun, Juyoung; Yu, Haejun; Lee, Jungsup; Jang, Jyongsik

2017-10-01

Paintable carbon electrode-based perovskite solar cells (PSCs) are of particular interest due to their material and fabrication process costs, as well as their moisture stability. However, printing the carbon paste on the perovskite layer limits the quality of the interface between the perovskite layer and carbon electrode. Herein, an attempt to enhance the performance of the paintable carbon-based PSCs is made using a modified solvent dripping method that involves dripping of the carbon nanotubes (CNTs), which is dispersed in chlorobenzene solution. This method allows CNTs to penetrate into both the perovskite film and carbon electrode, facilitating fast hole transport between the two layers. Furthermore, this method is results in increased open circuit voltage (V oc ) and fill factor (FF), providing better contact at the perovskite/carbon interfaces. The best devices made with CNT dripping show 13.57% power conversion efficiency and hysteresis-free performance. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

40 CFR Table 3 to Subpart Mmm of... - Monitoring Requirements for Control Devices a

Code of Federal Regulations, 2012 CFR

2012-07-01

.... Carbon adsorber (regenerative) Stream flow monitoring device, and 1. Total regeneration stream mass or volumetric flow during carbon bed regeneration cycle(s) 1. For each regeneration cycle, record the total regeneration stream mass or volumetric flow. Carbon bed temperature monitoring device 2. Temperature of carbon...

40 CFR Table 3 to Subpart Mmm of... - Monitoring Requirements for Control Devices a

Code of Federal Regulations, 2011 CFR

2011-07-01

.... Carbon adsorber (regenerative) Stream flow monitoring device, and 1. Total regeneration stream mass or volumetric flow during carbon bed regeneration cycle(s) 1. For each regeneration cycle, record the total regeneration stream mass or volumetric flow. Carbon bed temperature monitoring device 2. Temperature of carbon...

40 CFR Table 3 to Subpart Mmm of... - Monitoring Requirements for Control Devices a

Code of Federal Regulations, 2010 CFR

2010-07-01

.... Carbon adsorber (regenerative) Stream flow monitoring device, and 1. Total regeneration stream mass or volumetric flow during carbon bed regeneration cycle(s) 1. For each regeneration cycle, record the total regeneration stream mass or volumetric flow. Carbon bed temperature monitoring device 2. Temperature of carbon...

A Microchip-based Endothelium Mimic Utilizing Open Reservoirs for Cell Immobilization and Integrated Carbon Ink Microelectrodes for Detection

PubMed Central

Hulvey, Matthew K; Martin, R. Scott

2010-01-01

This paper describes the fabrication and characterization of a microfluidic device that utilizes a reservoir-based approach for endothelial cell immobilization and integrated embedded carbon ink microelectrodes for the amperometric detection of extracellular nitric oxide (NO) release. The design utilizes a buffer channel to continuously introduce buffer or a plug of stimulant to the reservoir as well as a separate sampling channel that constantly withdraws buffer from the reservoir and over the microelectrode. A steel pin is used for both the fluidic connection to the sampling channel and to provide a quasi-reference electrode for the carbon ink microelectrode. Characterization of the device was performed using NO standards produced from a NONOate salt. Finally, NO release from a layer of immobilized endothelial cells was monitored and quantified using the system. This system holds promise as a means to electrochemically detect extracellular NO release from endothelial cells in either an array of reservoirs or concurrently with fluorescence-based intracellular NO measurements. PMID:18989663

Dynamic Response of Exchange Bias in Graphene Nanoribbons

DTIC Science & Technology

2012-01-01

in establishing the GNRs-based spintronic devices. Keywords: Dynamic magnetic properties , exchange bias, training effect, field sweep rate and...transport properties by means of various applied conditions 6, 7 . The discovery 8 of weak ferromagnetism in polymerized C60 has invoked a special...attention to investigate the magnetic properties of carbon- based materials. Graphene is an allotrope of carbon and irradiation of graphene with ions

A photovoltaic self-powered gas sensor based on a single-walled carbon nanotube/Si heterojunction.

PubMed

Liu, L; Li, G H; Wang, Y; Wang, Y Y; Li, T; Zhang, T; Qin, S J

2017-12-07

We present a novel photovoltaic self-powered gas sensor based on a p-type single-walled carbon nanotube (SWNT) and n-type silicon (n-Si) heterojunction. The energy from visible light suffices to drive the device owing to a built-in electric field (BEF) induced by the differences between the Fermi levels of SWNTs and n-Si.

Mechanically robust, electrically conductive ultralow-density carbon nanotube-based aerogels

DOEpatents

Worsley, Marcus A.; Baumann, Theodore F.; Satcher, Jr., Joe H.

2016-10-04

Disclosed here is a device comprising a porous carbon aerogel or composite thereof as an energy storage material, catalyst support, sensor or adsorbent, wherein the porous carbon aerogel comprises a network of interconnected struts comprising carbon nanotube bundles covalently crosslinked by graphitic carbon nanoparticles, wherein the carbon nanotubes account for 5 to 95 wt. % of the aerogel and the graphitic carbon nanoparticles account for 5 to 95 wt. % of the aerogel, and wherein the aerogel has an electrical conductivity of at least 10 S/m and is capable of withstanding strains of more than 10% before fracture.

Conductive nanomaterials for printed electronics.

PubMed

Kamyshny, Alexander; Magdassi, Shlomo

2014-09-10

This is a review on recent developments in the field of conductive nanomaterials and their application in printed electronics, with particular emphasis on inkjet printing of ink formulations based on metal nanoparticles, carbon nanotubes, and graphene sheets. The review describes the basic properties of conductive nanomaterials suitable for printed electronics (metal nanoparticles, carbon nanotubes, and graphene), their stabilization in dispersions, formulations of conductive inks, and obtaining conductive patterns by using various sintering methods. Applications of conductive nanomaterials for electronic devices (transparent electrodes, metallization of solar cells, RFID antennas, TFTs, and light emitting devices) are also briefly reviewed.

Inter-allotropic transformations in the heterogeneous carbon nanotube networks.

PubMed

Jung, Hyun Young; Jung, Sung Mi; Kim, Dong Won; Jung, Yung Joon

2017-01-19

The allotropic transformations of carbon provide an immense technological interest for tailoring the desired molecular structures in the scalable nanoelectronic devices. Herein, we explore the effects of morphology and geometric alignment of the nanotubes for the re-engineering of carbon bonds in the heterogeneous carbon nanotube (CNT) networks. By applying alternating voltage pulses and electrical forces, the single-walled CNTs in networks were predominantly transformed into other predetermined sp 2 carbon structures (multi-walled CNTs and multi-layered graphitic nanoribbons), showing a larger intensity in a coalescence-induced mode of Raman spectra with the increasing channel width. Moreover, the transformed networks have a newly discovered sp 2 -sp 3 hybrid nanostructures in accordance with the alignment. The sp 3 carbon structures at the small channel are controlled, such that they contain up to about 29.4% networks. This study provides a controllable method for specific types of inter-allotropic transformations/hybridizations, which opens up the further possibility for the engineering of nanocarbon allotropes in the robust large-scale network-based devices.

Solid-State High Performance Flexible Supercapacitors Based on Polypyrrole-MnO2-Carbon Fiber Hybrid Structure

NASA Astrophysics Data System (ADS)

Tao, Jiayou; Liu, Nishuang; Ma, Wenzhen; Ding, Longwei; Li, Luying; Su, Jun; Gao, Yihua

2013-07-01

A solid-state flexible supercapacitor (SC) based on organic-inorganic composite structure was fabricated through an ``in situ growth for conductive wrapping'' and an electrode material of polypyrrole (PPy)-MnO2 nanoflakes-carbon fiber (CF) hybrid structure was obtained. The conductive organic material of PPy greatly improved the electrochemical performance of the device. With a high specific capacitance of 69.3 F cm-3 at a discharge current density of 0.1 A cm-3 and an energy density of 6.16 × 10-3 Wh cm-3 at a power density of 0.04 W cm-3, the device can drive a commercial liquid crystal display (LCD) after being charged. The organic-inorganic composite active materials have enormous potential in energy management and the ``in situ growth for conductive wrapping'' method might be generalized to open up new strategies for designing next-generation energy storage devices.

Computational Nanotechnology of Molecular Materials, Electronics, and Actuators with Carbon Nanotubes and Fullerenes

NASA Technical Reports Server (NTRS)

Srivastava, Deepak; Menon, Madhu; Cho, Kyeongjae; Biegel, Bryan (Technical Monitor)

2001-01-01

The role of computational nanotechnology in developing next generation of multifunctional materials, molecular scale electronic and computing devices, sensors, actuators, and machines is described through a brief review of enabling computational techniques and few recent examples derived from computer simulations of carbon nanotube based molecular nanotechnology.

Porous honeycomb structures formed from interconnected MnO2 sheets on CNT-coated substrates for flexible all-solid-state supercapacitors

NASA Astrophysics Data System (ADS)

Ko, Wen-Yin; Chen, You-Feng; Lu, Ke-Ming; Lin, Kuan-Jiuh

2016-01-01

The use of lightweight and easily-fabricated MnO2/carbon nanotube (CNT)-based flexible networks as binder-free electrodes and a polyvinyl alcohol/H2SO4 electrolyte for the formation of stretchable solid-state supercapacitors was examined. The active electrodes were fabricated from 3D honeycomb porous MnO2 assembled from cross-walled and interconnected sheet-architectural MnO2 on CNT-based plastic substrates (denoted as honeycomb MnO2/CNT textiles).These substrates were fabricated through a simple two-step procedure involving the coating of multi-walled carbon nanotubes (MWCNTs) onto commercial textiles by a dipping-drying process and subsequent electrodeposition of the interconnected MnO2 sheets onto the MWCNT-coated textile. With such unique MnO2 architectures integrated onto CNT flexible films, good performance was achieved with a specific capacitance of 324 F/g at 0.5 A/g. A maximum energy density of 7.2 Wh/kg and a power density as high as 3.3 kW/kg were exhibited by the honeycomb MnO2/CNT network device, which is comparable to the performance of other carbon-based and metal oxide/carbon-based solid-state supercapacitor devices. Specifically, the long-term cycling stability of this material is excellent, with almost no loss of its initial capacitance and good Coulombic efficiency of 82% after 5000 cycles. These impressive results identify these materials as a promising candidate for use in environmentally friendly, low-cost, and high-performance flexible energy-storage devices.

Porous honeycomb structures formed from interconnected MnO2 sheets on CNT-coated substrates for flexible all-solid-state supercapacitors

PubMed Central

Ko, Wen-Yin; Chen, You-Feng; Lu, Ke-Ming; Lin, Kuan-Jiuh

2016-01-01

The use of lightweight and easily-fabricated MnO2/carbon nanotube (CNT)-based flexible networks as binder-free electrodes and a polyvinyl alcohol/H2SO4 electrolyte for the formation of stretchable solid-state supercapacitors was examined. The active electrodes were fabricated from 3D honeycomb porous MnO2 assembled from cross-walled and interconnected sheet-architectural MnO2 on CNT-based plastic substrates (denoted as honeycomb MnO2/CNT textiles).These substrates were fabricated through a simple two-step procedure involving the coating of multi-walled carbon nanotubes (MWCNTs) onto commercial textiles by a dipping-drying process and subsequent electrodeposition of the interconnected MnO2 sheets onto the MWCNT-coated textile. With such unique MnO2 architectures integrated onto CNT flexible films, good performance was achieved with a specific capacitance of 324 F/g at 0.5 A/g. A maximum energy density of 7.2 Wh/kg and a power density as high as 3.3 kW/kg were exhibited by the honeycomb MnO2/CNT network device, which is comparable to the performance of other carbon-based and metal oxide/carbon-based solid-state supercapacitor devices. Specifically, the long-term cycling stability of this material is excellent, with almost no loss of its initial capacitance and good Coulombic efficiency of 82% after 5000 cycles. These impressive results identify these materials as a promising candidate for use in environmentally friendly, low-cost, and high-performance flexible energy-storage devices. PMID:26726724

Structural changes of electron and ion beam-deposited contacts in annealed carbon-based electrical devices.

PubMed

Batra, Nitin M; Patole, Shashikant P; Abdelkader, Ahmed; Anjum, Dalaver H; Deepak, Francis L; Costa, Pedro M F J

2015-11-06

The use of electron and ion beam deposition to make devices containing discrete nanostructures as interconnectors is a well-known nanofabrication process. Classically, one-dimensional materials such as carbon nanotubes (CNTs) have been electrically characterized by resorting to these beam deposition methods. While much attention has been given to the interconnectors, less is known about the contacting electrodes (or leads). In particular, the structure and chemistry of the electrode-interconnector interface is a topic that deserves more attention, as it is critical to understand the device behavior. Here, the structure and chemistry of Pt electrodes, deposited either with electron or ion beams and contacted to a CNT, are analyzed before and after thermally annealing the device in a vacuum. Free-standing Pt nanorods, acting as beam-deposited electrode models, are also characterized pre- and post-annealing. Overall, the as-deposited leads contain a non-negligible amount of amorphous carbon that is consolidated, upon heating, as a partially graphitized outer shell enveloping a Pt core. This observation raises pertinent questions regarding the definition of electrode-nanostructure interfaces in electrical devices, in particular long-standing assumptions of metal-CNT contacts fabricated by direct beam deposition methods.

Nanotechnology Based Materials and Devices for Health Care

NASA Technical Reports Server (NTRS)

Srivastava, Deepaka; Cho, K.; Brenner, Don; Menon, Madhu; Andriotis, Antonis; Sagman, Uri; Biegel, Bryan A. (Technical Monitor)

2002-01-01

This viewgraph presentation provides information on trends in NASA nanotechnology research and development, and future biotechnological applications for that nanotechnology. The presentation covers nanoelectronics, nanosensors, and nanomaterials, biomimetics, devices and materials for health care, carbon nanotubes, biosensors for astrobiology, solid-state nanopores for DNA sequencing, and protein nanotubes.

21 CFR 868.2480 - Cutaneous carbon dioxide (PcCO2) monitor.

Code of Federal Regulations, 2011 CFR

2011-04-01

... 21 Food and Drugs 8 2011-04-01 2011-04-01 false Cutaneous carbon dioxide (PcCO2) monitor. 868.2480... (CONTINUED) MEDICAL DEVICES ANESTHESIOLOGY DEVICES Monitoring Devices § 868.2480 Cutaneous carbon dioxide (PcCO2) monitor. (a) Identification. A cutaneous carbon dioxide (PcCO2) monitor is a noninvasive heated...

21 CFR 868.1430 - Carbon monoxide gas analyzer.

Code of Federal Regulations, 2012 CFR

2012-04-01

... 21 Food and Drugs 8 2012-04-01 2012-04-01 false Carbon monoxide gas analyzer. 868.1430 Section 868.1430 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES ANESTHESIOLOGY DEVICES Diagnostic Devices § 868.1430 Carbon monoxide gas analyzer. (a) Identification. A carbon monoxide gas...

21 CFR 868.1400 - Carbon dioxide gas analyzer.

Code of Federal Regulations, 2012 CFR

2012-04-01

... 21 Food and Drugs 8 2012-04-01 2012-04-01 false Carbon dioxide gas analyzer. 868.1400 Section 868.1400 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES ANESTHESIOLOGY DEVICES Diagnostic Devices § 868.1400 Carbon dioxide gas analyzer. (a) Identification. A carbon dioxide gas analyzer...

21 CFR 868.5300 - Carbon dioxide absorbent.

Code of Federal Regulations, 2011 CFR

2011-04-01

... 21 Food and Drugs 8 2011-04-01 2011-04-01 false Carbon dioxide absorbent. 868.5300 Section 868.5300 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES ANESTHESIOLOGY DEVICES Therapeutic Devices § 868.5300 Carbon dioxide absorbent. (a) Identification. A carbon dioxide absorbent is a...

21 CFR 868.5300 - Carbon dioxide absorbent.

Code of Federal Regulations, 2012 CFR

2012-04-01

... 21 Food and Drugs 8 2012-04-01 2012-04-01 false Carbon dioxide absorbent. 868.5300 Section 868.5300 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES ANESTHESIOLOGY DEVICES Therapeutic Devices § 868.5300 Carbon dioxide absorbent. (a) Identification. A carbon dioxide absorbent is a...

40 CFR 65.153 - Absorbers, condensers, carbon adsorbers, and other recovery devices used as final recovery devices.

Code of Federal Regulations, 2014 CFR

2014-07-01

..., an organic monitoring device capable of providing a continuous record, or an integrating regeneration... regeneration stream mass or volumetric flow for each regeneration cycle, and a carbon-bed temperature monitoring device capable of recording the carbon-bed temperature after each regeneration and within 15...

40 CFR 65.153 - Absorbers, condensers, carbon adsorbers, and other recovery devices used as final recovery devices.

Code of Federal Regulations, 2012 CFR

2012-07-01

..., an organic monitoring device capable of providing a continuous record, or an integrating regeneration... regeneration stream mass or volumetric flow for each regeneration cycle, and a carbon-bed temperature monitoring device capable of recording the carbon-bed temperature after each regeneration and within 15...

40 CFR 65.153 - Absorbers, condensers, carbon adsorbers, and other recovery devices used as final recovery devices.

Code of Federal Regulations, 2011 CFR

2011-07-01

..., an organic monitoring device capable of providing a continuous record, or an integrating regeneration... regeneration stream mass or volumetric flow for each regeneration cycle, and a carbon-bed temperature monitoring device capable of recording the carbon-bed temperature after each regeneration and within 15...

40 CFR 65.153 - Absorbers, condensers, carbon adsorbers, and other recovery devices used as final recovery devices.

Code of Federal Regulations, 2010 CFR

2010-07-01

..., an organic monitoring device capable of providing a continuous record, or an integrating regeneration... regeneration stream mass or volumetric flow for each regeneration cycle, and a carbon-bed temperature monitoring device capable of recording the carbon-bed temperature after each regeneration and within 15...

40 CFR 65.153 - Absorbers, condensers, carbon adsorbers, and other recovery devices used as final recovery devices.

Code of Federal Regulations, 2013 CFR

2013-07-01

..., an organic monitoring device capable of providing a continuous record, or an integrating regeneration... regeneration stream mass or volumetric flow for each regeneration cycle, and a carbon-bed temperature monitoring device capable of recording the carbon-bed temperature after each regeneration and within 15...

Device for detection and identification of carbon- and nitrogen-containing materials

DOEpatents

Karev, Alexander Ivanovich; Raevsky, Valery Georgievich; Dzhilavyan, Leonid Zavenovich; Laptev, Valery Dmitrievich; Pakhomov, Nikolay Ivanovich; Shvedunov, Vasily Ivanovich; Rykalin, Vladimir Ivanovich; Brothers, Louis Joseph; Wilhide, Larry K

2014-03-25

A device for detection and identification of carbon- and nitrogen-containing materials is described. In particular, the device performs the detection and identification of carbon- and nitrogen-containing materials by photo-nuclear detection. The device may comprise a race-track microtron, a breaking target, and a water-filled Cherenkov radiation counter.

MEMS- and NEMS-based smart devices and systems

NASA Astrophysics Data System (ADS)

Varadan, Vijay K.

2001-11-01

The microelectronics industry has seen explosive growth during the last thirty years. Extremely large markets for logic and memory devices have driven the development of new materials, and technologies for the fabrication of even more complex devices with features sized now don at the sub micron and nanometer level. Recent interest has arisen in employing these materials, tools and technologies for the fabrication of miniature sensors and actuators and their integration with electronic circuits to produce smart devices and systems. This effort offers the promise of: 1) increasing the performance and manufacturability of both sensors and actuators by exploiting new batch fabrication processes developed including micro stereo lithographic an micro molding techniques; 2) developing novel classes of materials and mechanical structures not possible previously, such as diamond like carbon, silicon carbide and carbon nanotubes, micro-turbines and micro-engines; 3) development of technologies for the system level and wafer level integration of micro components at the nanometer precision, such as self-assembly techniques and robotic manipulation; 4) development of control and communication systems for MEMS devices, such as optical and RF wireless, and power delivery systems, etc. A novel composite structure can be tailored by functionalizing carbon nano tubes and chemically bonding them with the polymer matrix e.g. block or graft copolymer, or even cross-linked copolymer, to impart exceptional structural, electronic and surface properties. Bio- and Mechanical-MEMS devices derived from this hybrid composite provide a new avenue for future smart systems. The integration of NEMS (NanoElectroMechanical Systems), MEMS, IDTs (Interdigital Transducers) and required microelectronics and conformal antenna in the multifunctional smart materials and composites results in a smart system suitable for sensing and control of a variety functions in automobile, aerospace, marine and civil structures and food and medical industries. This unique combination of technologies also results in novel conformal sensors that can be remotely sensed by an antenna system with the advantage of no power requirements at the sensor site. This paper provides a brief review of MEMS and NEMS based smart systems for various applications mentioned above. Carbon Nano Tubes (CNT) with their unique structure, have already proven to be valuable in their application as tips for scanning probe microscopy, field emission devices, nanoelectronics, H2-storage, electromagnetic absorbers, ESD, EMI films and coatings and structural composites. For many of these applications, highly purified and functionalized CNT which are compatible with many host polymers are needed. A novel microwave CVD processing technique to meet these requirements has been developed at Penn State Center for the engineering of Electronic and Acoustic Materials and Devices (CEEAMD). This method enables the production of highly purified carbon nano tubes with variable size (from 5-40 nm) at low cost (per gram) and high yield. Whereas, carbon nano tubes synthesized using the laser ablation or arc discharge evaporation method always include impurity due to catalyst or catalyst support. The Penn State research is based on the use of zeolites over other metal/metal oxides in the microwave field for a high production and uniformity of the product. An extended conventional purification method has been employed to purify our products in order to remove left over impurity. A novel composite structure can be tailored by functionalizing carbon nano tubes and chemically bonding them with the polymer matrix e.g. block or graft copolymer, or even cross- linked copolymer, to impart exceptional structural, electronic and surface properties. Bio- and Mechanical-MEMS devices derived from this hybrid composites will be presented.

Self aligned hysteresis free carbon nanotube field-effect transistors

NASA Astrophysics Data System (ADS)

Shlafman, M.; Tabachnik, T.; Shtempluk, O.; Razin, A.; Kochetkov, V.; Yaish, Y. E.

2016-04-01

Hysteresis phenomenon in the transfer characteristics of carbon nanotube field effect transistor (CNT FET) is being considered as the main obstacle for successful realization of electronic devices based on CNTs. In this study, we prepare four kinds of CNTFETs and explore their hysteretic behavior. Two kinds of devices comprise on-surface CNTs (type I) and suspended CNTs (type II) with thin insulating layer underneath and a single global gate which modulates the CNT conductance. The third and fourth types (types III and IV) consist of suspended CNT over a metallic local gate underneath, where for type IV the local gate was patterned self aligned with the source and drain electrodes. The first two types of devices, i.e., type I and II, exhibit substantial hysteresis which increases with scanning range and sweeping time. Under high vacuum conditions and moderate electric fields ( |E |>4 ×106 V /cm ), the hysteresis for on-surface devices cannot be eliminated, as opposed to suspended devices. Interestingly, type IV devices exhibit no hysteresis at all at ambient conditions, and from the different roles which the global and local gates play for the four types of devices, we could learn about the hysteresis mechanism of this system. We believe that these self aligned hysteresis free FETs will enable the realization of different electronic devices and sensors based on CNTs.

A novel adenine-based metal organic framework derived nitrogen-doped nanoporous carbon for flexible solid-state supercapacitor.

PubMed

Li, Haowen; Fu, Dongying; Zhang, Xian-Ming

2018-01-01

In this article, we have synthesized a series of nitrogen-doped nanoporous carbon (NPC) from metal organic framework of UiO-66 with different ratios of adenine and 1,4-benzendicarboxylate (H 2 BDC) coated on carbon nanotube film (CNTF) to obtain a flexible porous electrode (NPC/CNTF). It is worth noting that the introduction of adenine at different ratios did not change the structure of UiO-66. We also investigated the effect of carbonization temperature from 800 to 1000°C on the electrochemical properties of the NPC. The ratio (H 2 BDC:adenine) 9 : 1 and the NPC carbonized at 900°C (denoted as NPC-1-900) exhibits better electrochemical properties. The results show that NPC-1-900/CNTF electrode exhibits an exceptional areal capacitance of 121.5 mF cm -2 compared to that of PC-900/CNTF electrode (22.8 mF cm -2 ) at 5 mV s -1 in a three-electrode system, indicating that the incorporation of nitrogen is beneficial to the electrochemical properties of nanoporous carbon. A symmetric flexible solid-state supercapacitor of NPC-1-900/CNTF has also been assembled and tested. Electrochemical data show that the device exhibited superior areal capacitance (43.2 mF cm -2 ) at the scan rate of 5 mV s -1 ; the volumetric energy density is 57.3 µWh cm -3 and the volumetric power density is 2.4 mW cm -3 at the current density of 0.5 mA cm -2 based on poly(vinyl alcohol)/H 3 PO 4 gel electrolyte. For practical application, we have also studied the bending tests of the device, which show that the device exhibits outstanding mechanical stability under different bending angles. Furthermore, the flexible device shows excellent cyclic stability, which can retain 91.5% of the initial capacitance after 2000 cycles.

A novel adenine-based metal organic framework derived nitrogen-doped nanoporous carbon for flexible solid-state supercapacitor

PubMed Central

Li, Haowen; Zhang, Xian-Ming

2018-01-01

In this article, we have synthesized a series of nitrogen-doped nanoporous carbon (NPC) from metal organic framework of UiO-66 with different ratios of adenine and 1,4-benzendicarboxylate (H2BDC) coated on carbon nanotube film (CNTF) to obtain a flexible porous electrode (NPC/CNTF). It is worth noting that the introduction of adenine at different ratios did not change the structure of UiO-66. We also investigated the effect of carbonization temperature from 800 to 1000°C on the electrochemical properties of the NPC. The ratio (H2BDC:adenine) 9 : 1 and the NPC carbonized at 900°C (denoted as NPC-1-900) exhibits better electrochemical properties. The results show that NPC-1-900/CNTF electrode exhibits an exceptional areal capacitance of 121.5 mF cm−2 compared to that of PC-900/CNTF electrode (22.8 mF cm−2) at 5 mV s−1 in a three-electrode system, indicating that the incorporation of nitrogen is beneficial to the electrochemical properties of nanoporous carbon. A symmetric flexible solid-state supercapacitor of NPC-1-900/CNTF has also been assembled and tested. Electrochemical data show that the device exhibited superior areal capacitance (43.2 mF cm−2) at the scan rate of 5 mV s−1; the volumetric energy density is 57.3 µWh cm−3 and the volumetric power density is 2.4 mW cm−3 at the current density of 0.5 mA cm−2 based on poly(vinyl alcohol)/H3PO4 gel electrolyte. For practical application, we have also studied the bending tests of the device, which show that the device exhibits outstanding mechanical stability under different bending angles. Furthermore, the flexible device shows excellent cyclic stability, which can retain 91.5% of the initial capacitance after 2000 cycles. PMID:29410815

A Novel Type of Battery-Supercapacitor Hybrid Device with Highly Switchable Dual Performances Based on a Carbon Skeleton/Mg2Ni Free-Standing Hydrogen Storage Electrode.

PubMed

Li, Na; Du, Yi; Feng, Qing-Ping; Huang, Gui-Wen; Xiao, Hong-Mei; Fu, Shao-Yun

2017-12-27

The sharp proliferation of high power electronics and electrical vehicles has promoted growing demands for power sources with both high energy and power densities. Under these circumstances, battery-supercapacitor hybrid devices are attracting considerable attention as they combine the advantages of both batteries and supercapacitors. Here, a novel type of hybrid device based on a carbon skeleton/Mg 2 Ni free-standing electrode without the traditional nickel foam current collector is reported, which has been designed and fabricated through a dispersing-freeze-drying method by employing reduced graphene oxide (rGO) and multiwalled carbon nanotubes (MWCNTs) as a hybrid skeleton. As a result, the Mg 2 Ni alloy is able to deliver a high discharge capacity of 644 mAh g -1 and, more importantly, a high cycling stability with a retention of over 78% after 50 charge/discharge cycles have been achieved, which exceeds almost all the results ever reported on the Mg 2 Ni alloy. Simultaneously, the electrode could also exhibit excellent supercapacitor performances including high specific capacities (296 F g -1 ) and outstanding cycling stability (100% retention after 100 cycles). Moreover, the hybrid device can switch between battery and supercapacitor modes immediately as needed during application. These features make the C skeleton/alloy electrode a highly promising candidate for battery-supercapacitor hybrid devices with high power/energy density and favorable cycling stability.

Nanomaterial Based Sensors for NASA Missions

NASA Technical Reports Server (NTRS)

Koehne, Jessica E.

2016-01-01

Nanomaterials such as carbon nanotubes (CNTs), carbon nanofibers (CNFs), graphene and metal nanowires have shown interesting electronic properties and therefore have been pursued for a variety of space applications requiring ultrasensitive and light-weight sensor and electronic devices. We have been pursuing development of chemical and biosensors using carbon nanotubes and carbon nanofibers for the last several years and this talk will present the benefits of nanomaterials these applications. More recently, printing approaches to manufacturing these devices have been explored as a strategy that is compatible to a microgravity environment. Nanomaterials are either grown in house or purchased and processed as electrical inks. Chemical modification or coatings are added to the nanomaterials to tailor the nanomaterial to the exact application. The development of printed chemical sensors and biosensors will be discussed for applications ranging from crew life support to exploration missions.

Carbon nanotube transistor based high-frequency electronics

NASA Astrophysics Data System (ADS)

Schroter, Michael

At the nanoscale carbon nanotubes (CNTs) have higher carrier mobility and carrier velocity than most incumbent semiconductors. Thus CNT based field-effect transistors (FETs) are being considered as strong candidates for replacing existing MOSFETs in digital applications. In addition, the predicted high intrinsic transit frequency and the more recent finding of ways to achieve highly linear transfer characteristics have inspired investigations on analog high-frequency (HF) applications. High linearity is extremely valuable for an energy efficient usage of the frequency spectrum, particularly in mobile communications. Compared to digital applications, the much more relaxed constraints for CNT placement and lithography combined with already achieved operating frequencies of at least 10 GHz for fabricated devices make an early entry in the low GHz HF market more feasible than in large-scale digital circuits. Such a market entry would be extremely beneficial for funding the development of production CNTFET based process technology. This talk will provide an overview on the present status and feasibility of HF CNTFET technology will be given from an engineering point of view, including device modeling, experimental results, and existing roadblocks. Carbon nanotube transistor based high-frequency electronics.

The possibility of chemically inert, graphene-based all-carbon electronic devices with 0.8 eV gap.

PubMed

Qi, Jing Shan; Huang, Jian Yu; Feng, Ji; Shi, Da Ning; Li, Ju

2011-05-24

Graphene is an interesting electronic material. However, flat monolayer graphene does not have significant gap in the electronic density of states, required for a large on-off ratio in logic applications. We propose here a novel device architecture, composed of self-folded carbon nanotube-graphene hybrids, which have been recently observed experimentally in Joule-heated graphene. These experiments demonstrated the feasibility of cutting, folding, and welding few-layer graphene in situ to form all-carbon nanostructures with complex topologies. The electronic gap of self-folded nanotubes can be combined with the semimetallicity of graphene electrodes to form a "metal-semiconductor-metal" junction. By ab initio calculations we demonstrate large energy gaps in the transmission spectra of such junctions, which preserve the intrinsic transport characteristics of the semiconducting nanotubes despite topologically necessary disinclinations at the flat graphene-curved nanotube interface. These all-carbon devices are proposed to be constructed by contact probe cutting and high-temperature annealing and, if produced, would be chemically stable at room temperature under normal gas environments.

Programmable carbon nanotube membrane-based transdermal nicotine delivery with microdialysis validation assay.

PubMed

Gulati, Gaurav Kumar; Chen, Tao; Hinds, Bruce Jackson

2017-01-01

To evaluate the performance of switchable carbon nanotubes (CNT) membrane devices for transdermal nicotine delivery, we have developed an in-vitro microdialysis method that allow us to detect variable transdermal fluxes of nicotine through CNT devices and can be applied directly to in-vivo studies. Microdialysis membranes were placed beneath the porcine skin and its nicotine levels increased 6-8 times when the CNT membrane on skin was turned from OFF to ON state by application of bias. Fluxes in the ON state were approximately 3 times that of commercial nicotine patches and switching times were less than two hours, thus suggesting the improved therapeutic potential of our device. Blue tooth enabled CNT devices that can be programmed by smartphone and coupled with remote counseling application for enhanced smoking cessation treatments. Copyright © 2016. Published by Elsevier Inc.

Electrochemical energy storage device based on carbon dioxide as electroactive species

DOEpatents

Nemeth, Karoly; van Veenendaal, Michel Antonius; Srajer, George

2013-03-05

An electrochemical energy storage device comprising a primary positive electrode, a negative electrode, and one or more ionic conductors. The ionic conductors ionically connect the primary positive electrode with the negative electrode. The primary positive electrode comprises carbon dioxide (CO.sub.2) and a means for electrochemically reducing the CO.sub.2. This means for electrochemically reducing the CO.sub.2 comprises a conductive primary current collector, contacting the CO.sub.2, whereby the CO.sub.2 is reduced upon the primary current collector during discharge. The primary current collector comprises a material to which CO.sub.2 and the ionic conductors are essentially non-corrosive. The electrochemical energy storage device uses CO.sub.2 as an electroactive species in that the CO.sub.2 is electrochemically reduced during discharge to enable the release of electrical energy from the device.

Effective work function modulation of graphene/carbon nanotube composite films as transparent cathodes for organic optoelectronics.

PubMed

Huang, Jen-Hsien; Fang, Jheng-Hao; Liu, Chung-Chun; Chu, Chih-Wei

2011-08-23

In this study, we found that the work functions (Φ(w)) of solution-processable, functional graphene/carbon nanotube-based transparent conductors were readily manipulated, varying between 5.1 and 3.4 eV, depending on the nature of the doping alkali carbonate salt. We used the graphene-based electrodes possessing lower values of Φ(w) as cathodes in inverted-architecture polymer photovoltaic devices to effectively collect electrons, giving rise to an optimal power conversion efficiency of 1.27%. © 2011 American Chemical Society

An economical device for carbon supplement in large-scale micro-algae production.

PubMed

Su, Zhenfeng; Kang, Ruijuan; Shi, Shaoyuan; Cong, Wei; Cai, Zhaoling

2008-10-01

One simple but efficient carbon-supplying device was designed and developed, and the correlative carbon-supplying technology was described. The absorbing characterization of this device was studied. The carbon-supplying system proved to be economical for large-scale cultivation of Spirulina sp. in an outdoor raceway pond, and the gaseous carbon dioxide absorptivity was enhanced above 78%, which could reduce the production cost greatly.

Materials as additives for advanced lubrication

DOE Office of Scientific and Technical Information (OSTI.GOV)

Pol, Vilas G.; Thackeray, Michael M.; Mistry, Kuldeep

This invention relates to carbon-based materials as anti-friction and anti-wear additives for advanced lubrication purposes. The materials comprise carbon nanotubes suspended in a liquid hydrocarbon carrier. Optionally, the compositions further comprise a surfactant (e.g., to aid in dispersion of the carbon particles). Specifically, the novel lubricants have the ability to significantly lower friction and wear, which translates into improved fuel economies and longer durability of mechanical devices and engines.

Integration of Microchip Electrophoresis with Electrochemical Detection Using an Epoxy-Based Molding Method to Embed Multiple Electrode Materials

PubMed Central

Johnson, Alicia S.; Selimovic, Asmira; Martin, R. Scott

2012-01-01

This paper describes the use of epoxy-encapsulated electrodes to integrate microchip-based electrophoresis with electrochemical detection. Devices with various electrode combinations can easily be developed. This includes a palladium decoupler with a downstream working electrode material of either gold, mercury/gold, platinum, glassy carbon, or a carbon fiber bundle. Additional device components such as the platinum wires for the electrophoresis separation and the counter electrode for detection can also be integrated into the epoxy base. The effect of the decoupler configuration was studied in terms of the separation performance, detector noise, and the ability to analyze samples of a high ionic strength. The ability of both glassy carbon and carbon fiber bundle electrodes to analyze a complex mixture was demonstrated. It was also shown that a PDMS-based valving microchip can be used along with the epoxy embedded electrodes to integrate microdialysis sampling with microchip electrophoresis and electrochemical detection, with the microdialysis tubing also being embedded in the epoxy substrate. This approach enables one to vary the detection electrode material as desired in a manner where the electrodes can be polished and modified in a similar fashion to electrochemical flow cells used in liquid chromatography. PMID:22038707

Performance improvement induced by asymmetric Y2O3-coated device structure to carbon-nanotube-film based photodetectors

NASA Astrophysics Data System (ADS)

Wang, Fanglin; Xu, Haitao; Huang, Huixin; Ma, Ze; Wang, Sheng; Peng, Lian-Mao

2017-11-01

Film-based semiconducting carbon nanotube (CNT) photodetectors are promising candidates for industrial applications. However, unintentional doping from the environment such as water/oxygen (H2O/O2) redox, polymers, etc. changes the doping level of the CNT film. Here, we evaluate the performance of film-based barrier-free bipolar diodes (BFBDs), which are basically semiconducting CNT films asymmetrically contacted by perfect n-type ohmic contact (scandium, Sc) and p-type ohmic contact (palladium, Pd) at the two ends of the diode. We show that normal BFBD devices have large variances of forward current, reverse current, and photocurrent for different doping levels of the channel. We propose an asymmetric Y2O3-coated BFBD device in which the channel is covered by a layer of an Y2O3 film and an overlap between the Sc electrode and the Y2O3 film is designed. The Y2O3 film provides p-type doping to the channel. The overlap section increases the length of the base of the pn junction, and the diffusion current of holes is suppressed. In this way, the rectifier factors (current ratio when voltages are at +0.5 V and -0.5 V) of the asymmetric Y2O3-coated BFBD devices are around two orders of magnitude larger and the photocurrent generation is more stable compared to that of normal devices. Our results provide a way to conquer the influence of unintentional doping from the environment and suppress reverse current in pn diodes. This is beneficial to applications of CNT-based photodetectors and of importance for inspiring methods to improve the performances of devices based on other low dimensional materials.

Freestanding Aligned Multi-walled Carbon Nanotubes for Supercapacitor Devices

NASA Astrophysics Data System (ADS)

Moreira, João Vitor Silva; Corat, Evaldo José; May, Paul William; Cardoso, Lays Dias Ribeiro; Lelis, Pedro Almeida; Zanin, Hudson

2016-11-01

We report on the synthesis and electrochemical properties of multi-walled carbon nanotubes (MWCNTs) for supercapacitor devices. Freestanding vertically-aligned MWCNTs and MWCNT powder were grown concomitantly in a one-step chemical vapour deposition process. Samples were characterized by scanning and transmission electron microscopies and Fourier transform infrared and Raman spectroscopies. At similar film thicknesses and surface areas, the freestanding MWCNT electrodes showed higher electrochemical capacitance and gravimetric specific energy and power than the randomly-packed nanoparticle-based electrodes. This suggests that more ordered electrode film architectures facilitate faster electron and ion transport during the charge-discharge processes. Energy storage and supply or supercapacitor devices made from these materials could bridge the gap between rechargeable batteries and conventional high-power electrostatic capacitors.

One-step direct transfer of pristine single-walled carbon nanotubes for functional nanoelectronics.

PubMed

Wu, Chung Chiang; Liu, Chang Hua; Zhong, Zhaohui

2010-03-10

We report a one-step direct transfer technique for the fabrication of functional nanoelectronic devices using pristine single-walled carbon nanotubes (SWNTs). Suspended SWNTs grown by the chemical vapor deposition (CVD) method are aligned and directly transferred onto prepatterned device electrodes at ambient temperature. Using this technique, we successfully fabricated SWNT electromechanical resonators with gate-tunable resonance frequencies. A fully suspended SWNT p-n diode has also been demonstrated with the diode ideality factor equal to 1. Our method eliminates the organic residues on SWNTs resulting from conventional lithography and solution processing. The results open up opportunities for the fundamental study of electron transport physics in ultraclean SWNTs and for room temperature fabrication of novel functional devices based on pristine SWNTs.

Fabrication of transition metal-containing nanostructures via polymer templates for a multitude of applications

NASA Astrophysics Data System (ADS)

Lu, Jennifer Qing

Nanostructures such as carbon nanotubes and semiconducting nanowires offer great technological promise due to their remarkable properties. The lack of a rational synthesis method prevents fabricating these nanostructures with desirable and consistent properties at predefined locations for device applications. In this thesis, employing polymer templates, a variety of highly ordered catalytically active transition metal nanostructures, ranging from single metallic nanoparticles of Fe, Co, Ni, Au and bimetallic nanoparticles of Ni/Fe and Co/Mo to Fe-rich silicon oxide nanodomains with uniform and tunable size and spacing have been successfully synthesized. These nanostructures have been demonstrated to be excellent catalyst systems for the synthesis of carbon nanotube and silicon nanowire. High quality, small diameter carbon nanotubes and nanowires with narrow size distribution have been successfully attained. Because these catalytically active nanostructures are uniformly distributed and do not agglomerate at the growth temperatures, uniform, high density and high quality carbon nanotube mats have been obtained. Since this polymer template approach is fully compatible with conventional top-down photolithography, lithographically selective growth of carbon nanotubes on a surface or suspended carbon nanotubes across trenches have been produced by using existing semiconductor processing. We have also shown the feasibility of producing carbon nanotubes and silicon nanowires at predefined locations on a wafer format and established a wafer-level carbon nanotube based device fabrication process. The ability of the polymer template approach to control catalyst systems at the nano-, micro- and macro-scales paves a pathway for commercialization of these 1D nanostructure-enabled devices. Beside producing well-defined, highly ordered discrete catalytically active metal-containing nanostructures by the polymer template approach, Au and Ag nanotextured surfaces have also been attained by using a self-assembled ferrocenylsilane-based inorganic block copolymer template. These Au and Ag nanotextured surfaces exhibit different surface plasmon behavior than the nanotextured surface. Greatly enhanced and uniform Raman scattering have been observed on Ag nanotextured surfaces. Highly sensitive Au nanotextured surfaces suggest their potential application as sensing surfaces for SPR-based biodetection. This simple fabrication technique of producing inorganic nanostructures with adjustable properties such as size, spacing and composition offers great promise for both fundamental research and technological development.

Formate: an Energy Storage and Transport Bridge between Carbon Dioxide and a Formate Fuel Cell in a Single Device.

PubMed

Vo, Tracy; Purohit, Krutarth; Nguyen, Christopher; Biggs, Brenna; Mayoral, Salvador; Haan, John L

2015-11-01

We demonstrate the first device to our knowledge that uses a solar panel to power the electrochemical reduction of dissolved carbon dioxide (carbonate) into formate that is then used in the same device to operate a direct formate fuel cell (DFFC). The electrochemical reduction of carbonate is carried out on a Sn electrode in a reservoir that maintains a constant carbon balance between carbonate and formate. The electron-rich formate species is converted by the DFFC into electrical energy through electron release. The product of DFFC operation is the electron-deficient carbonate species that diffuses back to the reservoir bulk. It is possible to continuously charge the device using alternative energy (e.g., solar) to convert carbonate to formate for on-demand use in the DFFC; the intermittent nature of alternative energy makes this an attractive design. In this work, we demonstrate a proof-of-concept device that performs reduction of carbonate, storage of formate, and operation of a DFFC. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Room temperature infrared imaging sensors based on highly purified semiconducting carbon nanotubes.

PubMed

Liu, Yang; Wei, Nan; Zhao, Qingliang; Zhang, Dehui; Wang, Sheng; Peng, Lian-Mao

2015-04-21

High performance infrared (IR) imaging systems usually require expensive cooling systems, which are highly undesirable. Here we report the fabrication and performance characteristics of room temperature carbon nanotube (CNT) IR imaging sensors. The CNT IR imaging sensor is based on aligned semiconducting CNT films with 99% purity, and each pixel or device of the imaging sensor consists of aligned strips of CNT asymmetrically contacted by Sc and Pd. We found that the performance of the device is dependent on the CNT channel length. While short channel devices provide a large photocurrent and a rapid response of about 110 μs, long channel length devices exhibit a low dark current and a high signal-to-noise ratio which are critical for obtaining high detectivity. In total, 36 CNT IR imagers are constructed on a single chip, each consists of 3 × 3 pixel arrays. The demonstrated advantages of constructing a high performance IR system using purified semiconducting CNT aligned films include, among other things, fast response, excellent stability and uniformity, ideal linear photocurrent response, high imaging polarization sensitivity and low power consumption.

Highly stretchable strain sensor based on SWCNTs/CB synergistic conductive network for wearable human-activity monitoring and recognition

NASA Astrophysics Data System (ADS)

Guo, Xiaohui; Huang, Ying; Zhao, Yunong; Mao, Leidong; Gao, Le; Pan, Weidong; Zhang, Yugang; Liu, Ping

2017-09-01

Flexible, stretchable, and wearable strain sensors have attracted significant attention for their potential applications in human movement detection and recognition. Here, we report a highly stretchable and flexible strain sensor based on a single-walled carbon nanotube (SWCNTs)/carbon black (CB) synergistic conductive network. The fabrication, synergistic conductive mechanism, and characterization of the sandwich-structured strain sensor were investigated. The experimental results show that the device exhibits high stretchability (120%), excellent flexibility, fast response (˜60 ms), temperature independence, and superior stability and reproducibility during ˜1100 stretching/releasing cycles. Furthermore, human activities such as the bending of a finger or elbow and gestures were monitored and recognized based on the strain sensor, indicating that the stretchable strain sensor based on the SWCNTs/CB synergistic conductive network could have promising applications in flexible and wearable devices for human motion monitoring.

Sodium-oxygen batteries with alkyl-carbonate and ether based electrolytes.

PubMed

Kim, Jinsoo; Lim, Hee-Dae; Gwon, Hyeokjo; Kang, Kisuk

2013-03-14

Recently, metal-air batteries, such as lithium-air and zinc-air systems, have been studied extensively as potential candidates for ultra-high energy density storage devices because of their exceptionally high capacities. Here, we report such an electrochemical system based on sodium, which is abundant and inexpensive. Two types of sodium-oxygen batteries were introduced and studied, i.e. with carbonate and non-carbonate electrolytes. Both types could deliver specific capacities (2800 and 6000 mA h g(-1)) comparable to that of lithium-oxygen batteries but with slightly lower discharge voltages (2.3 V and 2.0 V). The reaction mechanisms of sodium-oxygen batteries in carbonate and non-carbonate electrolytes were investigated and compared with those of lithium-oxygen batteries.

Graphene and Carbon Quantum Dot-Based Materials in Photovoltaic Devices: From Synthesis to Applications

PubMed Central

Paulo, Sofia; Palomares, Emilio; Martinez-Ferrero, Eugenia

2016-01-01

Graphene and carbon quantum dots have extraordinary optical and electrical features because of their quantum confinement properties. This makes them attractive materials for applications in photovoltaic devices (PV). Their versatility has led to their being used as light harvesting materials or selective contacts, either for holes or electrons, in silicon quantum dot, polymer or dye-sensitized solar cells. In this review, we summarize the most common uses of both types of semiconducting materials and highlight the significant advances made in recent years due to the influence that synthetic materials have on final performance. PMID:28335285

Lightweight carbon nanotube-based structural-energy storage devices for micro unmanned systems

NASA Astrophysics Data System (ADS)

Rivera, Monica; Cole, Daniel P.; Hahm, Myung Gwan; Reddy, Arava L. M.; Vajtai, Robert; Ajayan, Pulickel M.; Karna, Shashi P.; Bundy, Mark L.

2012-06-01

There is a strong need for small, lightweight energy storage devices that can satisfy the ever increasing power and energy demands of micro unmanned systems. Currently, most commercial and developmental micro unmanned systems utilize commercial-off-the-shelf (COTS) lithium polymer batteries for their energy storage needs. While COTS lithium polymer batteries are the industry norm, the weight of these batteries can account for up to 60% of the overall system mass and the capacity of these batteries can limit mission durations to the order of only a few minutes. One method to increase vehicle endurance without adding mass or sacrificing payload capabilities is to incorporate multiple system functions into a single material or structure. For example, the body or chassis of a micro vehicle could be replaced with a multifunctional material that would serve as both the vehicle structure and the on-board energy storage device. In this paper we present recent progress towards the development of carbon nanotube (CNT)-based structural-energy storage devices for micro unmanned systems. Randomly oriented and vertically aligned CNT-polymer composite electrodes with varying degrees of flexibility are used as the primary building blocks for lightweight structural-supercapacitors. For the purpose of this study, the mechanical properties of the CNT-based electrodes and the charge-discharge behavior of the supercapacitor devices are examined. Because incorporating multifunctionality into a single component often degrades the properties or performance of individual structures, the performance and property tradeoffs of the CNT-based structural-energy storage devices will also be discussed.

Fabrication technology of CNT-Nickel Oxide based planar pseudocapacitor for MEMS and NEMS

NASA Astrophysics Data System (ADS)

Lebedev, E. A.; Kitsyuk, E. P.; Gavrilin, I. M.; Gromov, D. G.; Gruzdev, N. E.; Gavrilov, S. A.; Dronov, A. A.; Pavlov, A. A.

2015-11-01

Fabrication technology of planar pseudocapacitor (PsC) based on carbon nanotube (CNT) forest, synthesized using plasma enhanced chemical vapor deposition (PECVD) method, covered with thin nickel oxide layer deposited by successive ionic layer adsorption and reaction (SILAR) method, is demonstrated. Dependences of deposited oxide layers thickness on device specific capacities is studied. It is shown that pseudocapacity of nickel oxide thin layer increases specific capacity of the CNT's based device up to 2.5 times.

A Nonaqueous Potassium-Based Battery-Supercapacitor Hybrid Device.

PubMed

Fan, Ling; Lin, Kairui; Wang, Jue; Ma, Ruifang; Lu, Bingan

2018-05-01

A low cost nonaqueous potassium-based battery-supercapacitor hybrid device (BSH) is successfully established for the first time with soft carbon as the anode, commercialized activated carbon as the cathode, and potassium bis(fluoro-slufonyl)imide in dimethyl ether as the electrolyte. This BSH reconciles the advantages of potassium ion batteries and supercapacitors, achieving a high energy density of 120 W h kg -1 , a high power density of 599 W kg -1 , a long cycle life of 1500 cycles, and an ultrafast charge/slow discharge performance (energy density and power density are calculated based on the total mass of active materials in the anode and cathode). This work demonstrates a great potential of applying the nonaqueous BSH for low cost electric energy storage systems. © 2018 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Optically controlled dielectric properties of single-walled carbon nanotubes for terahertz wave applications.

PubMed

Smirnov, Serguei; Anoshkin, Ilya V; Demchenko, Petr; Gomon, Daniel; Lioubtchenko, Dmitri V; Khodzitsky, Mikhail; Oberhammer, Joachim

2018-06-21

Materials with tunable dielectric properties are valuable for a wide range of electronic devices, but are often lossy at terahertz frequencies. Here we experimentally report the tuning of the dielectric properties of single-walled carbon nanotubes under light illumination. The effect is demonstrated by measurements of impedance variations at low frequency as well as complex dielectric constant variations in the wide frequency range of 0.1-1 THz by time domain spectroscopy. We show that the dielectric constant is significantly modified for varying light intensities. The effect is also practically applied to phase shifters based on dielectric rod waveguides, loaded with carbon nanotube layers. The carbon nanotubes are used as tunable impedance surface controlled by light illumination, in the frequency range of 75-500 GHz. These results suggest that the effect of dielectric constant tuning with light, accompanied by low transmission losses of the carbon nanotube layer in such an ultra-wide band, may open up new directions for the design and fabrication of novel Terahertz and optoelectronic devices.

Large-scale complementary macroelectronics using hybrid integration of carbon nanotubes and IGZO thin-film transistors.

PubMed

Chen, Haitian; Cao, Yu; Zhang, Jialu; Zhou, Chongwu

2014-06-13

Carbon nanotubes and metal oxide semiconductors have emerged as important materials for p-type and n-type thin-film transistors, respectively; however, realizing sophisticated macroelectronics operating in complementary mode has been challenging due to the difficulty in making n-type carbon nanotube transistors and p-type metal oxide transistors. Here we report a hybrid integration of p-type carbon nanotube and n-type indium-gallium-zinc-oxide thin-film transistors to achieve large-scale (>1,000 transistors for 501-stage ring oscillators) complementary macroelectronic circuits on both rigid and flexible substrates. This approach of hybrid integration allows us to combine the strength of p-type carbon nanotube and n-type indium-gallium-zinc-oxide thin-film transistors, and offers high device yield and low device variation. Based on this approach, we report the successful demonstration of various logic gates (inverter, NAND and NOR gates), ring oscillators (from 51 stages to 501 stages) and dynamic logic circuits (dynamic inverter, NAND and NOR gates).

21 CFR 868.1430 - Carbon monoxide gas analyzer.

Code of Federal Regulations, 2011 CFR

2011-04-01

... techniques such as infrared absorption or gas chromatography. (b) Classification. Class II (performance... 21 Food and Drugs 8 2011-04-01 2011-04-01 false Carbon monoxide gas analyzer. 868.1430 Section 868...) MEDICAL DEVICES ANESTHESIOLOGY DEVICES Diagnostic Devices § 868.1430 Carbon monoxide gas analyzer. (a...

21 CFR 868.1430 - Carbon monoxide gas analyzer.

Code of Federal Regulations, 2010 CFR

2010-04-01

... techniques such as infrared absorption or gas chromatography. (b) Classification. Class II (performance... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Carbon monoxide gas analyzer. 868.1430 Section 868...) MEDICAL DEVICES ANESTHESIOLOGY DEVICES Diagnostic Devices § 868.1430 Carbon monoxide gas analyzer. (a...

Methods of forming semiconductor devices and devices formed using such methods

DOEpatents

Fox, Robert V; Rodriguez, Rene G; Pak, Joshua

2013-05-21

Single source precursors are subjected to carbon dioxide to form particles of material. The carbon dioxide may be in a supercritical state. Single source precursors also may be subjected to supercritical fluids other than supercritical carbon dioxide to form particles of material. The methods may be used to form nanoparticles. In some embodiments, the methods are used to form chalcopyrite materials. Devices such as, for example, semiconductor devices may be fabricated that include such particles. Methods of forming semiconductor devices include subjecting single source precursors to carbon dioxide to form particles of semiconductor material, and establishing electrical contact between the particles and an electrode.

Development of a paper-based carbon nanotube sensing microfluidic device for biological detection.

PubMed

Yang, Shih-I; Lei, Kin Fong; Tsai, Shiao-Wen; Hsu, Hsiao-Ting

2013-01-01

Carbon nanotube (CNT) has been utilized for the biological detection due to its extremely sensitive to biological molecules. A paper-based CNT sensing microfluidic device has been developed for the detection of protein, i.e., biotin-avidin, binding. We have developed a fabrication method that allows controlled deposition of bundled CNTs with well-defined dimensions to form sensors on paper. Then, polydimethyl siloxane (PDMS) was used to pattern the hydrophobic boundary on paper to form the reaction sites. The proposed fabrication method is based on vacuum filtration process with a metal mask covering on a filter paper for the definition of the dimension of sensor. The length, width, and thickness of the CNT-based sensors are readily controlled by the metal mask and the weight of the CNT powder used during the filtration process, respectively. Homogeneous deposition of CNTs with well-defined dimensions can be achieved. The CNT-based sensor on paper has been demonstrated on the detection of the protein binding. Biotin was first immobilized on the CNT's sidewall and avidin suspended solution was applied to the site. The result of the biotin-avidin binding was measured by the resistance change of the sensor, which is a label-free detection method. It showed the CNT is sensitive to the biological molecules and the proposed paper-based CNT sensing device is a possible candidate for point-of-care biosensors. Thus, electrical bio-assays on paper-based microfluidics can be realized to develop low cost, sensitive, and specific diagnostic devices.

Systems and methods for controlling diesel engine emissions

DOEpatents

Webb, Cynthia Chaffin; Weber, Phillip Anthony; Khair, Magdi K.

2004-06-01

Systems and methods for controlling diesel engine emissions, including, for example, oxides of nitrogen emissions, particulate matter emissions, and the like. The emission control system according to this invention is provided in the exhaust passageway of a diesel engine and includes a catalyst-based particulate filter; and first and second lean NO.sub.x trap systems coupled to the catalyst-based particulate filter. The first and second lean NO.sub.x trap systems are arranged in a parallel flow configuration with each other. Each of the first and second lean NO.sub.x trap systems include a carbon monoxide generating catalyst device, a sulfur trap device, a lean NO.sub.x device, a supplemental fuel injector device, and a plurality of flow diverter devices.

Water transport inside carbon nanotubes mediated by phonon-induced oscillating friction.

PubMed

Ma, Ming; Grey, François; Shen, Luming; Urbakh, Michael; Wu, Shuai; Liu, Jefferson Zhe; Liu, Yilun; Zheng, Quanshui

2015-08-01

The emergence of the field of nanofluidics in the last decade has led to the development of important applications including water desalination, ultrafiltration and osmotic energy conversion. Most applications make use of carbon nanotubes, boron nitride nanotubes, graphene and graphene oxide. In particular, understanding water transport in carbon nanotubes is key for designing ultrafiltration devices and energy-efficient water filters. However, although theoretical studies based on molecular dynamics simulations have revealed many mechanistic features of water transport at the molecular level, further advances in this direction are limited by the fact that the lowest flow velocities accessible by simulations are orders of magnitude higher than those measured experimentally. Here, we extend molecular dynamics studies of water transport through carbon nanotubes to flow velocities comparable with experimental ones using massive crowd-sourced computing power. We observe previously undetected oscillations in the friction force between water and carbon nanotubes and show that these oscillations result from the coupling between confined water molecules and the longitudinal phonon modes of the nanotube. This coupling can enhance the diffusion of confined water by more than 300%. Our results may serve as a theoretical framework for the design of new devices for more efficient water filtration and osmotic energy conversion devices.

Carbon Dioxide-Based versus Saline Tissue Expansion for Breast Reconstruction: Results of the XPAND Prospective, Randomized Clinical Trial.

PubMed

Ascherman, Jeffrey A; Zeidler, Kamakshi; Morrison, Kerry A; Appel, James Z; Berkowitz, R L; Castle, John; Colwell, Amy; Chun, Yoon; Johnson, Debra; Mohebali, Khashayar

2016-12-01

AeroForm is a new type of remote-controlled, needle-free, carbon dioxide-based expander involving a potentially faster method of tissue expansion. Results are presented here from the AirXpanders Patient Activated Controlled Tissue Expander pivotal trial comparing AeroForm to saline tissue expanders. Women undergoing two-stage breast reconstruction were randomized at 17 U.S. sites in this U.S. Food and Drug Administration-approved investigational device exemption trial. Expansion in the investigational arm was performed by the patient in 10-cc increments up to 30 cc/day of carbon dioxide and in the control arm by the physician with periodic bolus injections of saline. Safety endpoints, expansion and reconstruction times, pain, and satisfaction were assessed. One hundred fifty women were treated: 98 with carbon dioxide expanders (n = 168) and 52 with saline expanders (n = 88). The treatment success rate (all breasts exchanged successfully excluding non-device-related failures) was 96.1 percent for carbon dioxide and 98.8 percent for saline. Median time to full expansion and completion of the second-stage operation was 21.0 and 108.5 days (carbon dioxide) versus 46.0 and 136.5 days (saline), respectively, with a similar rate of overall complications. Ease of use for the carbon dioxide expander was rated high by patients (98 percent) and physicians (90 percent). The AirXpanders Patient Activated Controlled Tissue Expander trial results demonstrate that a carbon dioxide-based expander is an effective method of tissue expansion with a similar overall adverse event rate compared to saline expanders, and provides a more convenient and expedient expansion. Therapeutic, I.

21 CFR 876.1620 - Urodynamics measurement system.

Code of Federal Regulations, 2011 CFR

2011-04-01

... and pressure in the urinary bladder when it is filled through a catheter with carbon dioxide or water. The device controls the supply of carbon dioxide or water and may also record the electrical activity... electromyography. This generic type of device includes the cystometric gas (carbon dioxide) device, the cystometric...

Personal cooling air filtering device

DOEpatents

Klett, James [Knoxville, TN; Conway, Bret [Denver, NC

2002-08-13

A temperature modification system for modifying the temperature of fluids includes at least one thermally conductive carbon foam element, the carbon foam element having at least one flow channel for the passage of fluids. At least one temperature modification device is provided, the temperature modification device thermally connected to the carbon foam element and adapted to modify the temperature of the carbon foam to modify the temperature of fluids flowing through the flow channels. Thermoelectric and/or thermoionic elements can preferably be used as the temperature modification device. A method for the reversible temperature modification of fluids includes the steps of providing a temperature modification system including at least one thermally conductive carbon foam element having flow channels and at least one temperature modification device, and flowing a fluid through the flow channels.

A novel screen-printed microfluidic paper-based electrochemical device for detection of glucose and uric acid in urine.

PubMed

Yao, Yong; Zhang, Chunsun

2016-10-01

A novel screen-printed microfluidic paper-based analytical device with all-carbon electrode-enabled electrochemical assay (SP-ACE-EC-μPAD) has been developed. The fabrication of these devices involved wax screen-printing, which was simple, low-cost and energy-efficient. The working, counter and reference electrodes were screen-printed using carbon ink on the patterned paper devices. Different wax screen-printing processes were examined and optimized, which led to an improved method with a shorter heating time (~5 s) and a lower heating temperature (75 °C). Different printing screens were examined, with a 300-mesh polyester screen yielding the highest quality wax screen-prints. The carbon electrodes were screen-printed on the μPADs and then examined using cyclic voltammetry. The analytical performance of the SP-ACE-EC-μPADs for the detection of glucose and uric acid in standard solutions was investigated. The results were reproducible, with a linear relationship [R(2) = 0.9987 (glucose) or 0.9997 (uric acid)] within the concentration range of interest, and with detection limits as low as 0.35 mM (glucose) and 0.08 mM (uric acid). To determine the clinical utility of the μPADs, chronoamperometry was used to analyze glucose and uric acid in real urine samples using the standard addition method. Our devices were able to detect the analytes of interest in complex real-world biological samples, and have the potential for use in a wide variety of applications.

Preparation and electrical-property characterization of poly(vinyl chloride)-derived carbon nanosheet by ion beam irradiation-induced carbon clustering and carbonization

NASA Astrophysics Data System (ADS)

Jung, Chan-Hee; Sohn, Joon-Yong; Kim, Hyo-Sub; Hwang, In-Tae; Lee, Hong-Joon; Shin, Junhwa; Choi, Jae-Hak

2018-05-01

In this work, we demonstrated that carbon nanosheet (CNS) can easily be produced by a room-temperature, solid-state proton irradiation-induced clustering of poly(vinyl chloride) (PVC) films followed by carbonization. The results of the optical, chemical, and structural analyses revealed that oxidized and sp2-hybridized carbon clusters were effectively created in the PVC thin film by combined dehydrochlorination and inter-coupling reactions during proton irradiation. This was further converted to pseudo-hexagonally-structured nano-crystalline CNS with 2-D symmetry and metallic transporting character by high-temperature treatment. As a result, the CNS exhibited a very high electrical conductivity (587 S/cm) without a significant change in their thickness, a low surface roughness (0.36 nm), and a high work function (5.11 eV). These findings demonstrate that the radiation-based approach opens new avenues for the design and development of 2-D CNS as a graphene allotrope for the application of electronic devices, including field-effect transistors, electric heating devices, biosensors, supercapacitors, and fuel cells.

Strain Sensitivity in Single Walled Carbon Nanotubes for Multifunctional Materials

NASA Technical Reports Server (NTRS)

Heath, D. M. (Technical Monitor); Smits, Jan M., VI

2005-01-01

Single walled carbon nanotubes represent the future of structural aerospace vehicle systems due to their unparalleled strength characteristics and demonstrated multifunctionality. This multifunctionality rises from the CNT's unique capabilities for both metallic and semiconducting electron transport, electron spin polarizability, and band gap modulation under strain. By incorporating the use of electric field alignment and various lithography techniques, a single wall carbon nanotube (SWNT) test bed for measurement of conductivity/strain relationships has been developed. Nanotubes are deposited at specified locations through dielectrophoresis. The circuit is designed such that the central, current carrying section of the nanotube is exposed to enable atomic force microscopy and manipulation in situ while the transport properties of the junction are monitored. By applying this methodology to sensor development a flexible single wall carbon nanotube (SWNT) based strain sensitive device has been developed. Studies of tensile testing of the flexible SWNT device vs conductivity are also presented, demonstrating the feasibility of using single walled HiPCO (high-pressure carbon monoxide) carbon nanotubes as strain sensing agents in a multi-functional materials system.

Integrating Desalination and Energy Storage using a Saltwater-based Hybrid Sodium-ion Supercapacitor.

PubMed

Guo, Zhaowei; Ma, Yuanyuan; Dong, Xiaoli; Hou, Mengyan; Wang, Yonggang; Xia, Yongyao

2018-06-11

Ever-increasing freshwater scarcity and energy crisis problems require efficient seawater desalination and energy storage technologies; however, each target is generally considered separately. Herein, a hybrid sodium-ion supercapacitor, involving a carbon-coated nano-NaTi 2 (PO 4 ) 3 -based battery anode and an activated-carbon-based capacitive cathode, is developed to combine desalination and energy storage in one device. On charge, the supercapacitor removes salt in a flowing saltwater electrolyte through Cl - electrochemical adsorption at the cathode and Na + intercalation at the anode. Discharge delivers useful electric energy and regenerates the electrodes. This supercapacitor can be used not only for energy storage with promising electrochemical performance (i.e., high power, high efficiency, and long cycle life), but also as a desalination device with desalination capacity of 146.8 mg g -1 , much higher than most reported capacitive and battery desalination devices. Finally, we demonstrate renewables to usable electric energy and desalted water through combining commercial photovoltaics and this hybrid supercapacitor. © 2018 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

Advances in Carbon Nanotubes-Hydrogel Hybrids in Nanomedicine for Therapeutics.

PubMed

Vashist, Arti; Kaushik, Ajeet; Vashist, Atul; Sagar, Vidya; Ghosal, Anujit; Gupta, Y K; Ahmad, Sharif; Nair, Madhavan

2018-05-01

In spite of significant advancement in hydrogel technology, low mechanical strength and lack of electrical conductivity have limited their next-level biomedical applications for skeletal muscles, cardiac and neural cells. Host-guest chemistry based hybrid nanocomposites systems have gained attention as they completely overcome these pitfalls and generate bioscaffolds with tunable electrical and mechanical characteristics. In recent years, carbon nanotube (CNT)-based hybrid hydrogels have emerged as innovative candidates with diverse applications in regenerative medicines, tissue engineering, drug delivery devices, implantable devices, biosensing, and biorobotics. This article is an attempt to recapitulate the advancement in synthesis and characterization of hybrid hydrogels and provide deep insights toward their functioning and success as biomedical devices. The improved comparative performance and biocompatibility of CNT-hydrogels hybrids systems developed for targeted biomedical applications are addressed here. Recent updates toward diverse applications and limitations of CNT hybrid hydrogels is the strength of the review. This will provide a holistic approach toward understanding of CNT-based hydrogels and their applications in nanotheranostics. © 2018 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Applications and Methods of Operating a Three-dimensional Nano-electro-mechanical Resonator and Related Devices

NASA Technical Reports Server (NTRS)

Kaul, Anupama B. (Inventor); Epp, Larry W. (Inventor); Bagge, Leif (Inventor)

2013-01-01

Carbon nanofiber resonator devices, methods for use, and applications of said devices are disclosed. Carbon nanofiber resonator devices can be utilized in or as high Q resonators. Resonant frequency of these devices is a function of configuration of various conducting components within these devices. Such devices can find use, for example, in filtering and chemical detection.

Hydroelectric voltage generation based on water-filled single-walled carbon nanotubes.

PubMed

Yuan, Quanzi; Zhao, Ya-Pu

2009-05-13

A DFT/MD mutual iterative method was employed to give insights into the mechanism of voltage generation based on water-filled single-walled carbon nanotubes (SWCNTs). Our calculations showed that a constant voltage difference of several mV would generate between the two ends of a carbon nanotube, due to interactions between the water dipole chains and charge carriers in the tube. Our work validates this structure of a water-filled SWCNT as a promising candidate for a synthetic nanoscale power cell, as well as a practical nanopower harvesting device at the atomic level.

Thiolate/disulfide organic redox couples for efficient organic dye-sensitized solar cells

NASA Astrophysics Data System (ADS)

Li, Wen-Yan; Zheng, Hai-Kuo; Wang, Jian-Wen; Zhang, Le-Le; Han, Hui-Min; Wu, Ming-Xing

2017-08-01

A series of organic thiolate/disulfide redox couples based on benz-imidazole/othiazole/oxazole have been synthesized and applied to dye-sensitized solar cells (DSCs). Platinum (Pt) and carbon material are introduced as counter electrode (CE) catalysts towards this kind of organic redox couples regeneration and the photovoltaic performance of the DSCs using this organic redox couples has been investigated. The carbon CE shows high catalytic activity than Pt for the organic redox couples and the DSCs using carbon CE exhibit much higher efficiencies than those of the Pt CE-based devices.

A Novel Electro-Thermal Laminated Ceramic with Carbon-Based Layer

PubMed Central

Ji, Yi; Huang, Bin; Rao, Pinggen

2017-01-01

A novel electro-thermal laminated ceramic composed of ceramic tile, carbon-based layer, dielectric layer, and foaming ceramic layer was designed and prepared by tape casting. The surface temperature achieved at an applied voltage of 10 V by the laminated ceramics was 40.3 °C when the thickness of carbon-based suspension was 1.0 mm and the adhesive strength between ceramic tile and carbon-based layer was 1.02 ± 0.06 MPa. In addition, the thermal aging results at 100 °C up to 192 h confirmed the high thermal stability and reliability of the electro-thermal laminated ceramics. The development of this laminated ceramic with excellent electro-thermal properties and safety provides a new individual heating device which is highly expected to be widely applied in the field of indoor heat supply. PMID:28773006

A Novel Electro-Thermal Laminated Ceramic with Carbon-Based Layer.

PubMed

Ji, Yi; Huang, Bin; Rao, Pinggen

2017-06-12

A novel electro-thermal laminated ceramic composed of ceramic tile, carbon-based layer, dielectric layer, and foaming ceramic layer was designed and prepared by tape casting. The surface temperature achieved at an applied voltage of 10 V by the laminated ceramics was 40.3 °C when the thickness of carbon-based suspension was 1.0 mm and the adhesive strength between ceramic tile and carbon-based layer was 1.02 ± 0.06 MPa. In addition, the thermal aging results at 100 °C up to 192 h confirmed the high thermal stability and reliability of the electro-thermal laminated ceramics. The development of this laminated ceramic with excellent electro-thermal properties and safety provides a new individual heating device which is highly expected to be widely applied in the field of indoor heat supply.

Fast Electromechanical Switches Based on Carbon Nanotubes

NASA Technical Reports Server (NTRS)

Kaul, Anupama; Wong, Eric; Epp, Larry

2008-01-01

Electrostatically actuated nanoelectromechanical switches based on carbon nanotubes have been fabricated and tested in a continuing effort to develop high-speed switches for a variety of stationary and portable electronic equipment. As explained below, these devices offer advantages over electrostatically actuated microelectromechanical switches, which, heretofore, have represented the state of the art of rapid, highly miniaturized electromechanical switches. Potential applications for these devices include computer memories, cellular telephones, communication networks, scientific instrumentation, and general radiation-hard electronic equipment. A representative device of the present type includes a single-wall carbon nanotube suspended over a trench about 130 nm wide and 20 nm deep in an electrically insulating material. The ends of the carbon nanotube are connected to metal electrodes, denoted the source and drain electrodes. At bottom of the trench is another metal electrode, denoted the pull electrode (see figure). In the off or open switch state, no voltage is applied, and the nanotube remains out of contact with the pull electrode. When a sufficiently large electric potential (switching potential) is applied between the pull electrode and either or both of the source and drain electrodes, the resulting electrostatic attraction bends and stretches the nanotube into contact with the pull electrode, thereby putting the switch into the "on" or "closed" state, in which substantial current (typically as much as hundreds of nanoamperes) is conducted. Devices of this type for use in initial experiments were fabricated on a thermally oxidized Si wafer, onto which Nb was sputter-deposited for use as the pull-electrode layer. Nb was chosen because its refractory nature would enable it to withstand the chemical and thermal conditions to be subsequently imposed for growing carbon nanotubes. A 200- nm-thick layer of SiO2 was formed on top of the Nb layer by plasma-enhanced chemical vapor deposition. In the device regions, the SiO2 layer was patterned to thin it to the 20-nm trench depth. The trenches were then patterned by electron- beam lithography and formed by reactive- ion etching of the pattern through the 20-nm-thick SiO2 to the Nb layer.

From Lab to Fab: Developing a Nanoscale Delivery Tool for Scalable Nanomanufacturing

NASA Astrophysics Data System (ADS)

Safi, Asmahan A.

The emergence of nanomaterials with unique properties at the nanoscale over the past two decades carries a capacity to impact society and transform or create new industries ranging from nanoelectronics to nanomedicine. However, a gap in nanomanufacturing technologies has prevented the translation of nanomaterial into real-world commercialized products. Bridging this gap requires a paradigm shift in methods for fabricating structured devices with a nanoscale resolution in a repeatable fashion. This thesis explores the new paradigms for fabricating nanoscale structures devices and systems for high throughput high registration applications. We present a robust and scalable nanoscale delivery platform, the Nanofountain Probe (NFP), for parallel direct-write of functional materials. The design and microfabrication of NFP is presented. The new generation addresses the challenges of throughput, resolution and ink replenishment characterizing tip-based nanomanufacturing. To achieve these goals, optimized probe geometry is integrated to the process along with channel sealing and cantilever bending. The capabilities of the newly fabricated probes are demonstrated through two type of delivery: protein nanopatterning and single cell nanoinjection. The broad applications of the NFP for single cell delivery are investigated. An external microfluidic packaging is developed to enable delivery in liquid environment. The system is integrated to a combined atomic force microscope and inverted fluorescence microscope. Intracellular delivery is demonstrated by injecting a fluorescent dextran into Hela cells in vitro while monitoring the injection forces. Such developments enable in vitro cellular delivery for single cell studies and high throughput gene expression. The nanomanufacturing capabilities of NFPs are explored. Nanofabrication of carbon nanotube-based electronics presents all the manufacturing challenges characterizing of assembling nanomaterials precisely onto devices. The presented study combines top-down and bottom-approaches by integrating the catalyst patterning and carbon nanotube growth directly on structures. Large array of iron-rich catalyst are patterned on an substrate for subsequent carbon nanotubes synthesis. The dependence of probe geometry and substrate wetting is assessed by modeling and experimental studies. Finally preliminary results on synthesis of carbon nanotube by catalyst assisted chemical vapor deposition suggest increasing the catalyst yield is critical. Such work will enable high throughput nanomanufacturing of carbon nanotube based devices.

Improved switching reliability achieved in HfOx based RRAM with mountain-like surface-graphited carbon layer

NASA Astrophysics Data System (ADS)

Tao, Ye; Ding, Wentao; Wang, Zhongqiang; Xu, Haiyang; Zhao, Xiaoning; Li, Xuhong; Liu, Weizhen; Ma, Jiangang; Liu, Yichun

2018-05-01

In this work, we demonstrated an effective method to improve the switching reliability of HfOx based RRAM device by inserting mountain-like surface-graphited carbon (MSGC) layer. The MSGC layer was fabricated through thermal annealing of amorphous carbon (a-C) film with high sp2 proportion (49.7%) under 500 °C on Pt substrate, whose characteristics were validated by XPS and Raman spectrums. The local electric-field (LEF) was enhanced around the nanoscale tips of MSGC layer due to large surface curvature, which leads to simplified CFs and localization of resistive switching region. It takes responsibility to the reduction of high/low resistance states (HRS/LRS) fluctuation from 173.8%/64.9% to 23.6%/6.5%, respectively. In addition, the resulting RRAM devices exhibited fast switching speed (<65 ns), good retention (>104 s at 85 °C) and low cycling degradation. This method could be promising to develop reliable and repeatable high-performance RRAM for practical applications.

Self-Powered, Flexible, and Solution-Processable Perovskite Photodetector Based on Low-Cost Carbon Cloth.

PubMed

Sun, Haoxuan; Lei, Tianyu; Tian, Wei; Cao, Fengren; Xiong, Jie; Li, Liang

2017-07-01

Flexible perovskite photodetectors are usually constructed on indium-tin-oxide-coated polymer substrates, which are expensive, fragile, and not resistant to high temperature. Herein, for the first time, a high-performance flexible perovskite photodetector is fabricated based on low-cost carbon cloth via a facile solution processable strategy. In this device, perovskite microcrystal and Spiro-OMeTAD (hole transporting material) blended film act as active materials for light detection, and carbon cloth serves as both a flexible substrate and a conductive electrode. The as-fabricated photodetector shows a broad spectrum response from ultraviolet to near-infrared light, high responsivity, fast response speed, long-term stability, and self-powered capability. Flexible devices show negligible degradation after several tens of bending cycles and at the extremely bending angle of 180°. This work promises a new technique to construct flexible, high-performance photodetectors with low cost and self-powered capability. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Multiphase flow simulations of a moving fluidized bed regenerator in a carbon capture unit

DOE Office of Scientific and Technical Information (OSTI.GOV)

Sarkar, Avik; Pan, Wenxiao; Suh, Dong-Myung

2014-10-01

To accelerate the commercialization and deployment of carbon capture technologies, computational fluid dynamics (CFD)-based tools may be used to model and analyze the performance of carbon capture devices. This work presents multiphase CFD-based flow simulations for the regeneration device responsible for extracting CO 2 from CO 2-loaded sorbent particles before the particles are recycled. The use of solid particle sorbents in this design is a departure from previously reported systems, where aqueous sorbents are employed. Another new feature is the inclusion of a series of perforated plates along the regenerator height. The influence of these plates on sorbent distribution ismore » examined for varying sorbent holdup, fluidizing gas velocity, and particle size. The residence time distribution of sorbents is also measured to classify the low regime as plug flow or well-mixed flow. The purpose of this work is to better understand the sorbent flow characteristics before reaction kinetics of CO 2 desorption can be implemented.« less

An effective device for gas-liquid oxygen removal in enclosed microalgae culture.

PubMed

Su, Zhenfeng; Kang, Ruijuan; Shi, Shaoyuan; Cong, Wei; Cai, Zhaoling

2010-01-01

A high-performance gas-liquid transmission device (HPTD) was described in this paper. To investigate the HPTD mass transfer characteristics, the overall volumetric mass transfer coefficients, K(A)(La,CO(2)) for the absorption of gaseous CO(2) and K(A)(La,O(2)) for the desorption of dissolved O(2) were determined, respectively, by titration and dissolved oxygen electrode. The mass transfer capability of carbon dioxide was compared with that of dissolved oxygen in the device, and the operating conditions were optimized to suit for the large-scale enclosed micro-algae cultivation. Based on the effectiveness evaluation of the HPTD applied in one enclosed flat plate Spirulina culture system, it was confirmed that the HPTD can satisfy the demand of the enclosed system for carbon supplement and excessive oxygen removal.

Variability and reliability analysis in self-assembled multichannel carbon nanotube field-effect transistors

NASA Astrophysics Data System (ADS)

Hu, Zhaoying; Tulevski, George S.; Hannon, James B.; Afzali, Ali; Liehr, Michael; Park, Hongsik

2015-06-01

Carbon nanotubes (CNTs) have been widely studied as a channel material of scaled transistors for high-speed and low-power logic applications. In order to have sufficient drive current, it is widely assumed that CNT-based logic devices will have multiple CNTs in each channel. Understanding the effects of the number of CNTs on device performance can aid in the design of CNT field-effect transistors (CNTFETs). We have fabricated multi-CNT-channel CNTFETs with an 80-nm channel length using precise self-assembly methods. We describe compact statistical models and Monte Carlo simulations to analyze failure probability and the variability of the on-state current and threshold voltage. The results show that multichannel CNTFETs are more resilient to process variation and random environmental fluctuations than single-CNT devices.

Solid-State High Performance Flexible Supercapacitors Based on Polypyrrole-MnO2-Carbon Fiber Hybrid Structure

PubMed Central

Tao, Jiayou; Liu, Nishuang; Ma, Wenzhen; Ding, Longwei; Li, Luying; Su, Jun; Gao, Yihua

2013-01-01

A solid-state flexible supercapacitor (SC) based on organic-inorganic composite structure was fabricated through an “in situ growth for conductive wrapping” and an electrode material of polypyrrole (PPy)-MnO2 nanoflakes-carbon fiber (CF) hybrid structure was obtained. The conductive organic material of PPy greatly improved the electrochemical performance of the device. With a high specific capacitance of 69.3 F cm−3 at a discharge current density of 0.1 A cm−3 and an energy density of 6.16 × 10−3 Wh cm−3 at a power density of 0.04 W cm−3, the device can drive a commercial liquid crystal display (LCD) after being charged. The organic-inorganic composite active materials have enormous potential in energy management and the “in situ growth for conductive wrapping” method might be generalized to open up new strategies for designing next-generation energy storage devices. PMID:23884478

Graphene-based carbon-layered electrode array technology for neural imaging and optogenetic applications

PubMed Central

Park, Dong-Wook; Schendel, Amelia A.; Mikael, Solomon; Brodnick, Sarah K.; Richner, Thomas J.; Ness, Jared P.; Hayat, Mohammed R.; Atry, Farid; Frye, Seth T.; Pashaie, Ramin; Thongpang, Sanitta; Ma, Zhenqiang; Williams, Justin C.

2014-01-01

Neural micro-electrode arrays that are transparent over a broad wavelength spectrum from ultraviolet to infrared could allow for simultaneous electrophysiology and optical imaging, as well as optogenetic modulation of the underlying brain tissue. The long-term biocompatibility and reliability of neural micro-electrodes also require their mechanical flexibility and compliance with soft tissues. Here we present a graphene-based, carbon-layered electrode array (CLEAR) device, which can be implanted on the brain surface in rodents for high-resolution neurophysiological recording. We characterize optical transparency of the device at >90% transmission over the ultraviolet to infrared spectrum and demonstrate its utility through optical interface experiments that use this broad spectrum transparency. These include optogenetic activation of focal cortical areas directly beneath electrodes, in vivo imaging of the cortical vasculature via fluorescence microscopy and 3D optical coherence tomography. This study demonstrates an array of interfacing abilities of the CLEAR device and its utility for neural applications. PMID:25327513

Magnetoresistance devices based on single-walled carbon nanotubes

NASA Astrophysics Data System (ADS)

Hod, Oded; Rabani, Eran; Baer, Roi

2005-08-01

We demonstrate the physical principles for the construction of a nanometer-sized magnetoresistance device based on the Aharonov-Bohm effect [Phys. Rev. 115, 485 (1959)]. The proposed device is made of a short single-walled carbon nanotube (SWCNT) placed on a substrate and coupled to a tip/contacts. We consider conductance due to the motion of electrons along the circumference of the tube (as opposed to the motion parallel to its axis). We find that the circumference conductance is sensitive to magnetic fields threading the SWCNT due to the Aharonov-Bohm effect, and show that by retracting the tip/contacts, so that the coupling to the SWCNT is reduced, very high sensitivity to the threading magnetic field develops. This is due to the formation of a narrow resonance through which the tunneling current flows. Using a bias potential the resonance can be shifted to low magnetic fields, allowing the control of conductance with magnetic fields of the order of 1 T.

Bolometric-Effect-Based Wavelength-Selective Photodetectors Using Sorted Single Chirality Carbon Nanotubes

PubMed Central

Zhang, Suoming; Cai, Le; Wang, Tongyu; Shi, Rongmei; Miao, Jinshui; Wei, Li; Chen, Yuan; Sepúlveda, Nelson; Wang, Chuan

2015-01-01

This paper exploits the chirality-dependent optical properties of single-wall carbon nanotubes for applications in wavelength-selective photodetectors. We demonstrate that thin-film transistors made with networks of carbon nanotubes work effectively as light sensors under laser illumination. Such photoresponse was attributed to photothermal effect instead of photogenerated carriers and the conclusion is further supported by temperature measurements. Additionally, by using different types of carbon nanotubes, including a single chirality (9,8) nanotube, the devices exhibit wavelength-selective response, which coincides well with the absorption spectra of the corresponding carbon nanotubes. This is one of the first reports of controllable and wavelength-selective bolometric photoresponse in macroscale assemblies of chirality-sorted carbon nanotubes. The results presented here provide a viable route for achieving bolometric-effect-based photodetectors with programmable response spanning from visible to near-infrared by using carbon nanotubes with pre-selected chiralities. PMID:26643777

Low dimensional carbon electronics

NASA Astrophysics Data System (ADS)

Herring, Patrick Kenichi

This thesis covers several different experiments that comprised my graduate career. The main focus of these experiments was the use of carbon as an electronic material and a steady evolution of fabrication recipes that allowed us to perform reliable and consistent measurements. The second chapter describes experiments with carbon nanotubes, where our goal was to produce devices capable of manipulating electronic spin states in order create quantum bits or "qubits." The third chapter covers the development of fabrication recipes with the goal of creating qubits within Si-Ge nanowire, and the bottom-gating approach that was developed. The fourth chapter begins graphene related research, describing one of the simplest uses of graphene as a simple transparent electrode on a SiN micromembrane. The remainder of the thesis describes experiments that develop graphene based optical and infrared detectors, study their characteristics and determine the physics that underlies their detection mechanism. Key in these experiments were the fabrication recipes that had been developed to create carbon nanotube and Si-Ge nanowire devices. Finally, we demonstrate how engineering of the device's thermal characteristics can lead to improved sensitivity and how graphene can be used in novel applications where conventional materials are not suitable.

Low-cost electrodes for stable perovskite solar cells

NASA Astrophysics Data System (ADS)

Bastos, João P.; Manghooli, Sara; Jaysankar, Manoj; Tait, Jeffrey G.; Qiu, Weiming; Gehlhaar, Robert; De Volder, Michael; Uytterhoeven, Griet; Poortmans, Jef; Paetzold, Ulrich W.

2017-06-01

Cost-effective production of perovskite solar cells on an industrial scale requires the utilization of exclusively inexpensive materials. However, to date, highly efficient and stable perovskite solar cells rely on expensive gold electrodes since other metal electrodes are known to cause degradation of the devices. Finding a low-cost electrode that can replace gold and ensure both efficiency and long-term stability is essential for the success of the perovskite-based solar cell technology. In this work, we systematically compare three types of electrode materials: multi-walled carbon nanotubes (MWCNTs), alternative metals (silver, aluminum, and copper), and transparent oxides [indium tin oxide (ITO)] in terms of efficiency, stability, and cost. We show that multi-walled carbon nanotubes are the only electrode that is both more cost-effective and stable than gold. Devices with multi-walled carbon nanotube electrodes present remarkable shelf-life stability, with no decrease in the efficiency even after 180 h of storage in 77% relative humidity (RH). Furthermore, we demonstrate the potential of devices with multi-walled carbon nanotube electrodes to achieve high efficiencies. These developments are an important step forward to mass produce perovskite photovoltaics in a commercially viable way.

40 CFR Table 4 to Subpart Ggg of... - Monitoring Requirements for Control Devices a

Code of Federal Regulations, 2011 CFR

2011-07-01

... monitoring device, and 1. Total regeneration stream mass or volumetric flow during carbon bed regeneration cycle(s) 1. For each regeneration cycle, record the total regeneration stream mass or volumetric flow. Carbon bed temperature monitoring device 2. Temperature of carbon bed after regeneration 2. For each...

40 CFR 63.990 - Absorbers, condensers, and carbon adsorbers used as control devices.

Code of Federal Regulations, 2012 CFR

2012-07-01

... adsorber is used, an integrating regeneration stream flow monitoring device having an accuracy of ±10 percent or better, capable of recording the total regeneration stream mass or volumetric flow for each regeneration cycle; and a carbon bed temperature monitoring device, capable of recording the carbon bed...

40 CFR 63.990 - Absorbers, condensers, and carbon adsorbers used as control devices.

Code of Federal Regulations, 2014 CFR

2014-07-01

... adsorber is used, an integrating regeneration stream flow monitoring device having an accuracy of ±10 percent or better, capable of recording the total regeneration stream mass or volumetric flow for each regeneration cycle; and a carbon bed temperature monitoring device, capable of recording the carbon bed...

40 CFR Table 4 to Subpart Ggg of... - Monitoring Requirements for Control Devices a

Code of Federal Regulations, 2012 CFR

2012-07-01

... monitoring device, and 1. Total regeneration stream mass or volumetric flow during carbon bed regeneration cycle(s) 1. For each regeneration cycle, record the total regeneration stream mass or volumetric flow. Carbon bed temperature monitoring device 2. Temperature of carbon bed after regeneration 2. For each...

40 CFR 63.990 - Absorbers, condensers, and carbon adsorbers used as control devices.

Code of Federal Regulations, 2011 CFR

2011-07-01

... adsorber is used, an integrating regeneration stream flow monitoring device having an accuracy of ±10 percent or better, capable of recording the total regeneration stream mass or volumetric flow for each regeneration cycle; and a carbon bed temperature monitoring device, capable of recording the carbon bed...

40 CFR Table 4 to Subpart Ggg of... - Monitoring Requirements for Control Devices a

Code of Federal Regulations, 2010 CFR

2010-07-01

... monitoring device, and 1. Total regeneration stream mass or volumetric flow during carbon bed regeneration cycle(s) 1. For each regeneration cycle, record the total regeneration stream mass or volumetric flow. Carbon bed temperature monitoring device 2. Temperature of carbon bed after regeneration 2. For each...

40 CFR 63.990 - Absorbers, condensers, and carbon adsorbers used as control devices.

Code of Federal Regulations, 2013 CFR

2013-07-01

... adsorber is used, an integrating regeneration stream flow monitoring device having an accuracy of ±10 percent or better, capable of recording the total regeneration stream mass or volumetric flow for each regeneration cycle; and a carbon bed temperature monitoring device, capable of recording the carbon bed...

40 CFR 63.990 - Absorbers, condensers, and carbon adsorbers used as control devices.

Code of Federal Regulations, 2010 CFR

2010-07-01

... adsorber is used, an integrating regeneration stream flow monitoring device having an accuracy of ±10 percent or better, capable of recording the total regeneration stream mass or volumetric flow for each regeneration cycle; and a carbon bed temperature monitoring device, capable of recording the carbon bed...

The applications of carbon nanomaterials in fiber-shaped energy storage devices

NASA Astrophysics Data System (ADS)

Wu, Jingxia; Hong, Yang; Wang, Bingjie

2018-01-01

As a promising candidate for future demand, fiber-shaped electrochemical energy storage devices, such as supercapacitors and lithium-ion batteries have obtained considerable attention from academy to industry. Carbon nanomaterials, such as carbon nanotube and graphene, have been widely investigated as electrode materials due to their merits of light weight, flexibility and high capacitance. In this review, recent progress of carbon nanomaterials in flexible fiber-shaped energy storage devices has been summarized in accordance with the development of fibrous electrodes, including the diversified electrode preparation, functional and intelligent device structure, and large-scale production of fibrous electrodes or devices. Project supported by the National Natural Science Foundation of China (Nos. 21634003, 21604012).

Carbon Nanofiber versus Graphene‐Based Stretchable Capacitive Touch Sensors for Artificial Electronic Skin

PubMed Central

Dussoni, Simeone; Ceseracciu, Luca; Maggiali, Marco; Natale, Lorenzo; Metta, Giorgio; Athanassiou, Athanassia

2017-01-01

Abstract Stretchable capacitive devices are instrumental for new‐generation multifunctional haptic technologies particularly suited for soft robotics and electronic skin applications. A majority of elongating soft electronics still rely on silicone for building devices or sensors by multiple‐step replication. In this study, fabrication of a reliable elongating parallel‐plate capacitive touch sensor, using nitrile rubber gloves as templates, is demonstrated. Spray coating both sides of a rubber piece cut out of a glove with a conductive polymer suspension carrying dispersed carbon nanofibers (CnFs) or graphene nanoplatelets (GnPs) is sufficient for making electrodes with low sheet resistance values (≈10 Ω sq−1). The electrodes based on CnFs maintain their conductivity up to 100% elongation whereas the GnPs‐based ones form cracks before 60% elongation. However, both electrodes are reliable under elongation levels associated with human joints motility (≈20%). Strikingly, structural damages due to repeated elongation/recovery cycles could be healed through annealing. Haptic sensing characteristics of a stretchable capacitive device by wrapping it around the fingertip of a robotic hand (ICub) are demonstrated. Tactile forces as low as 0.03 N and as high as 5 N can be easily sensed by the device under elongation or over curvilinear surfaces. PMID:29619306

Gate-defined Quantum Confinement in Suspended Bilayer Graphene

NASA Astrophysics Data System (ADS)

Allen, Monica

2013-03-01

Quantum confined devices in carbon-based materials offer unique possibilities for applications ranging from quantum computation to sensing. In particular, nanostructured carbon is a promising candidate for spin-based quantum computation due to the ability to suppress hyperfine coupling to nuclear spins, a dominant source of spin decoherence. Yet graphene lacks an intrinsic bandgap, which poses a serious challenge for the creation of such devices. We present a novel approach to quantum confinement utilizing tunnel barriers defined by local electric fields that break sublattice symmetry in suspended bilayer graphene. This technique electrostatically confines charges via band structure control, thereby eliminating the edge and substrate disorder that hinders on-chip etched nanostructures to date. We report clean single electron tunneling through gate-defined quantum dots in two regimes: at zero magnetic field using the energy gap induced by a perpendicular electric field and at finite magnetic fields using Landau level confinement. The observed Coulomb blockade periodicity agrees with electrostatic simulations based on local top-gate geometry, a direct demonstration of local control over the band structure of graphene. This technology integrates quantum confinement with pristine device quality and access to vibrational modes, enabling wide applications from electromechanical sensors to quantum bits. More broadly, the ability to externally tailor the graphene bandgap over nanometer scales opens a new unexplored avenue for creating quantum devices.

Carbon Nanofiber versus Graphene-Based Stretchable Capacitive Touch Sensors for Artificial Electronic Skin.

PubMed

Cataldi, Pietro; Dussoni, Simeone; Ceseracciu, Luca; Maggiali, Marco; Natale, Lorenzo; Metta, Giorgio; Athanassiou, Athanassia; Bayer, Ilker S

2018-02-01

Stretchable capacitive devices are instrumental for new-generation multifunctional haptic technologies particularly suited for soft robotics and electronic skin applications. A majority of elongating soft electronics still rely on silicone for building devices or sensors by multiple-step replication. In this study, fabrication of a reliable elongating parallel-plate capacitive touch sensor, using nitrile rubber gloves as templates, is demonstrated. Spray coating both sides of a rubber piece cut out of a glove with a conductive polymer suspension carrying dispersed carbon nanofibers (CnFs) or graphene nanoplatelets (GnPs) is sufficient for making electrodes with low sheet resistance values (≈10 Ω sq -1 ). The electrodes based on CnFs maintain their conductivity up to 100% elongation whereas the GnPs-based ones form cracks before 60% elongation. However, both electrodes are reliable under elongation levels associated with human joints motility (≈20%). Strikingly, structural damages due to repeated elongation/recovery cycles could be healed through annealing. Haptic sensing characteristics of a stretchable capacitive device by wrapping it around the fingertip of a robotic hand (ICub) are demonstrated. Tactile forces as low as 0.03 N and as high as 5 N can be easily sensed by the device under elongation or over curvilinear surfaces.

Modeling and experimental study of resistive switching in vertically aligned carbon nanotubes

NASA Astrophysics Data System (ADS)

Ageev, O. A.; Blinov, Yu F.; Ilina, M. V.; Ilin, O. I.; Smirnov, V. A.

2016-08-01

Model of the resistive switching in vertically aligned carbon nanotube (VA CNT) taking into account the processes of deformation, polarization and piezoelectric charge accumulation have been developed. Origin of hysteresis in VA CNT-based structure is described. Based on modeling results the VACNTs-based structure has been created. The ration resistance of high-resistance to low-resistance states of the VACNTs-based structure amounts 48. The correlation the modeling results with experimental studies is shown. The results can be used in the development nanoelectronics devices based on VA CNTs, including the nonvolatile resistive random-access memory.

Considerably improved photovoltaic performance of carbon nanotube-based solar cells using metal oxide layers.

PubMed

Wang, Feijiu; Kozawa, Daichi; Miyauchi, Yuhei; Hiraoka, Kazushi; Mouri, Shinichiro; Ohno, Yutaka; Matsuda, Kazunari

2015-02-18

Carbon nanotube-based solar cells have been extensively studied from the perspective of potential application. Here we demonstrated a significant improvement of the carbon nanotube solar cells by the use of metal oxide layers for efficient carrier transport. The metal oxides also serve as an antireflection layer and an efficient carrier dopant, leading to a reduction in the loss of the incident solar light and an increase in the photocurrent, respectively. As a consequence, the photovoltaic performance of both p-single-walled carbon nanotube (SWNT)/n-Si and n-SWNT/p-Si heterojunction solar cells using MoOx and ZnO layers is improved, resulting in very high photovoltaic conversion efficiencies of 17.0 and 4.0%, respectively. These findings regarding the use of metal oxides as multifunctional layers suggest that metal oxide layers could improve the performance of various electronic devices based on carbon nanotubes.

Highly Crumpled All-Carbon Transistors for Brain Activity Recording.

PubMed

Yang, Long; Zhao, Yan; Xu, Wenjing; Shi, Enzheng; Wei, Wenjing; Li, Xinming; Cao, Anyuan; Cao, Yanping; Fang, Ying

2017-01-11

Neural probes based on graphene field-effect transistors have been demonstrated. Yet, the minimum detectable signal of graphene transistor-based probes is inversely proportional to the square root of the active graphene area. This fundamentally limits the scaling of graphene transistor-based neural probes for improved spatial resolution in brain activity recording. Here, we address this challenge using highly crumpled all-carbon transistors formed by compressing down to 16% of its initial area. All-carbon transistors, chemically synthesized by seamless integration of graphene channels and hybrid graphene/carbon nanotube electrodes, maintained structural integrity and stable electronic properties under large mechanical deformation, whereas stress-induced cracking and junction failure occurred in conventional graphene/metal transistors. Flexible, highly crumpled all-carbon transistors were further verified for in vivo recording of brain activity in rats. These results highlight the importance of advanced material and device design concepts to make improvements in neuroelectronics.

Considerably improved photovoltaic performance of carbon nanotube-based solar cells using metal oxide layers

NASA Astrophysics Data System (ADS)

Wang, Feijiu; Kozawa, Daichi; Miyauchi, Yuhei; Hiraoka, Kazushi; Mouri, Shinichiro; Ohno, Yutaka; Matsuda, Kazunari

2015-02-01

Carbon nanotube-based solar cells have been extensively studied from the perspective of potential application. Here we demonstrated a significant improvement of the carbon nanotube solar cells by the use of metal oxide layers for efficient carrier transport. The metal oxides also serve as an antireflection layer and an efficient carrier dopant, leading to a reduction in the loss of the incident solar light and an increase in the photocurrent, respectively. As a consequence, the photovoltaic performance of both p-single-walled carbon nanotube (SWNT)/n-Si and n-SWNT/p-Si heterojunction solar cells using MoOx and ZnO layers is improved, resulting in very high photovoltaic conversion efficiencies of 17.0 and 4.0%, respectively. These findings regarding the use of metal oxides as multifunctional layers suggest that metal oxide layers could improve the performance of various electronic devices based on carbon nanotubes.

A population-based exposure assessment methodology for carbon monoxide: Development of a carbon monoxide passive sampler and occupational dosimeter

DOE Office of Scientific and Technical Information (OSTI.GOV)

Apte, Michael G.

Two devices, an occupational carbon monoxide (CO) dosimeter (LOCD), and an indoor air quality (IAQ) passive sampler were developed for use in population-based CO exposure assessment studies. CO exposure is a serious public health problem in the U.S., causing both morbidity and mortality (lifetime mortality risk approximately 10{sup -4}). Sparse data from population-based CO exposure assessments indicate that approximately 10% of the U.S. population is exposed to CO above the national ambient air quality standard. No CO exposure measurement technology is presently available for affordable population-based CO exposure assessment studies. The LOCD and IAQ Passive Sampler were tested in themore » laboratory and field. The palladium-molybdenum based CO sensor was designed into a compact diffusion tube sampler that can be worn. Time-weighted-average (TWA) CO exposure of the device is quantified by a simple spectrophotometric measurement. The LOCD and IAQ Passive Sampler were tested over an exposure range of 40 to 700 ppm-hours and 200 to 4200 ppm-hours, respectively. Both devices were capable of measuring precisely (relative standard deviation <20%), with low bias (<10%). The LOCD was screened for interferences by temperature, humidity, and organic and inorganic gases. Temperature effects were small in the range of 10°C to 30°C. Humidity effects were low between 20% and 90% RH. Ethylene (200 ppm) caused a positive interference and nitric oxide (50 ppm) caused a negative response without the presence of CO but not with CO.« less

Catalyst patterning for nanowire devices

NASA Technical Reports Server (NTRS)

Li, Jun (Inventor); Cassell, Alan M. (Inventor); Han, Jie (Inventor)

2004-01-01

Nanowire devices may be provided that are based on carbon nanotubes or single-crystal semiconductor nanowires. The nanowire devices may be formed on a substrate. Catalyst sites may be formed on the substrate. The catalyst sites may be formed using lithography, thin metal layers that form individual catalyst sites when heated, collapsible porous catalyst-filled microscopic spheres, microscopic spheres that serve as masks for catalyst deposition, electrochemical deposition techniques, and catalyst inks. Nanowires may be grown from the catalyst sites.

21 CFR 878.3500 - Polytetrafluoroethylene with carbon fibers composite implant material.

Code of Federal Regulations, 2011 CFR

2011-04-01

... 21 Food and Drugs 8 2011-04-01 2011-04-01 false Polytetrafluoroethylene with carbon fibers... Prosthetic Devices § 878.3500 Polytetrafluoroethylene with carbon fibers composite implant material. (a) Identification. A polytetrafluoroethylene with carbon fibers composite implant material is a porous device...

Photovoltaic device using single wall carbon nanotubes and method of fabricating the same

DOEpatents

Biris, Alexandru S.; Li, Zhongrui

2012-11-06

A photovoltaic device and methods for forming the same. In one embodiment, the photovoltaic device has a silicon substrate, and a film comprising a plurality of single wall carbon nanotubes disposed on the silicon substrate, wherein the plurality of single wall carbon nanotubes forms a plurality of heterojunctions with the silicon in the substrate.

Ozone sensing based on palladium decorated carbon nanotubes.

PubMed

Colindres, Selene Capula; Aguir, Khalifa; Cervantes Sodi, Felipe; Vargas, Luis Villa; Salazar, José Moncayo; Febles, Vicente Garibay

2014-04-14

Multiwall carbon nanotubes (MWCNTs) were easily and efficiently decorated with Pd nanoparticles through a vapor-phase impregnation-decomposition method starting from palladium acetylacetonates. The sensor device consisted on a film of sensitive material (MWCNTs-Pd) deposited by drop coating on platinum interdigitated electrodes on a SiO₂ substrate. The sensor exhibited a resistance change to ozone (O₃) with a response time of 60 s at different temperatures and the capability of detecting concentrations up to 20 ppb. The sensor shows the best response when exposed to O3 at 120 °C. The device shows a very reproducible sensor performance, with high repeatability, full recovery and efficient response.

Plasmonic thermal IR emitters based on nanoamorphous carbon

NASA Astrophysics Data System (ADS)

Tay, Savaş; Kropachev, Aleksandr; Araci, Ismail Emre; Skotheim, Terje; Norwood, Robert A.; Peyghambarian, N.

2009-02-01

The development of plasmonic narrow-band thermal mid-IR emitters made from a conducting amorphous carbon composite is shown. These IR emitters have greatly improved thermal and mechanical stability compared to metallic emitters as they can be operated at 600 °C in air without any degradation in performance. The emitted thermal radiation has a bandwidth of 0.5 μm and can be set to the desired wavelength from 3 to 15 μm by changing the surface periodicity. The periodically patterned devices have in-band emissivities significantly exceeding that of the non-patterned devices, constituting simple yet efficient radiation sources at this important wavelength range.

Strain-induced negative differential resistance in ultrasmall carbon nanotube

NASA Astrophysics Data System (ADS)

Fang, Hui; Zhang, Fei-Peng; Ruan, Xing-Xiang; Huang, Can-Sheng; Jiang, Zhi-Nian; Peng, Jin-Yun; Wang, Ru-Zhi

2017-08-01

The transport properties in ultrasmall single-wall carbon nanotubes (SWCNTs) under tensile strain have been theoretically investigated. The regular negative differential resistance (NDR) induced by the strain undergoes a process from enhancement to weakening in the zigzag (3,0) SWCNT. The NDR achieves maximum with applying 4% tensile strain. Compared to the case of (3,0) SWCNT, that NDR cannot be manipulated by applying strain clearly in (4,0) and (5,0) ultrasmall SWCNTs with tensile strain lower than 10%. It proposes this strain-induced NDR effect to demonstrate the possibility of finding potential applications in SWCNT-based NDR nanodevices such as in memory devices, oscillators and fast switching devices.

Nanotechnology: MEMS and NEMS and their applications to smart systems and devices

NASA Astrophysics Data System (ADS)

Varadan, Vijay K.

2003-10-01

The microelectronics industry has seen explosive growth during the last thirty years. Extremely large markets for logic and memory devices have driven the development of new materials, and technologies for the fabrication of even more complex devices with features sizes now down at the sub micron and nanometer level. Recent interest has arisen in employing these materials, tools and technologies for the fabrication of miniature sensors and actuators and their integration with electronic circuits to produce smart devices and systems. This effort offers the promise of: (1) increasing the performance and manufacturability of both sensors and actuators by exploiting new batch fabrication processes developed including micro stereo lithographic and micro molding techniques; (2) developing novel classes of materials and mechanical structures not possible previously, such as diamond like carbon, silicon carbide and carbon nanotubes, micro-turbines and micro-engines; (3) development of technologies for the system level and wafer level integration of micro components at the nanometer precision, such as self-assembly techniques and robotic manipulation; (4) development of control and communication systems for MEMS devices, such as optical and RF wireless, and power delivery systems, etc. A novel composite structure can be tailored by functionalizing carbon nano tubes and chemically bonding them with the polymer matrix e.g. block or graft copolymer, or even cross-linked copolymer, to impart exceptional structural, electronic and surface properties. Bio- and Mechanical-MEMS devices derived from this hybrid composite provide a new avenue for future smart systems. The integration of NEMS (NanoElectroMechanical Systems), MEMS, IDTs (Interdigital Transducers) and required microelectronics and conformal antenna in the multifunctional smart materials and composites results in a smart system suitable for sending and control of a variety functions in automobile, aerospace, marine and civil strutures and food and medical industries. This unique combination of technologies also results in novel conformal sensors that can be remotely sensed by an antenna system with the advantage of no power requirements at the sensor site. This paper provides a brief review of MEMS and NEMS based smart systems for various applications mentioned above. Carbon Nano Tubes (CNT) with their unique structure, have already proven to be valuable in their application as tips for scanning probe microscopy, field emission devices, nanoelectronics, H2-storage, electromagnetic absorbers, ESD, EMI films and coatings and structural composites. For many of these applications, highly purified and functionalized CNT which are compatible with many host polymers are needed. A novel microwave CVD processing technique to meet these requirements has been developed at Penn State Center for the Engineering of Electronic and Acoustic Materials and Devices (CEEAMD). This method enables the production of highly purified carbon nano tubes with variable size (from 5 - 40 nm) at low cost (per gram) and high yield. Whereas, carbon nano tubes synthesized using the laser ablation or arc discharge evaporation method always include impurity due to catalyst or catalyst support. The Penn State research is based on the use of zeolites over other metal/metal oxides in the microwave field for a high production and uniformity of the product. An extended coventional purification method has been employed to purify our products in order to remove left over impurity. A novel composite structure can be tailored by functionalizing carbon nano tubes and chemically bonding them with the polymer matrix e.g. block or graft copolymer, or even cross-linked copolymer, to impart exceptional structural, electronic and surface properties. Bio- and Mechanical-MEMS devices derived from this hybrid composites will be presented.

Electrocatalytic interface based on novel carbon nanomaterials for advanced electrochemical sensors

DOE PAGES

Zhou, Ming; Guo, Shaojun

2015-07-17

The rapid development of nanoscience and nanotechnology provides new opportunities for the sustainable progress of nanoscale catalysts (i.e., nanocatalysts). The introduction of nanocatalysts into electronic devices implants their novel functions into electronic sensing systems, resulting in the testing of many advanced electrochemical sensors and the fabrication of some highly sensitive, selective, and stable sensing platforms. In this Review, we will summarize recent significant progress on exploring advanced carbon nanomaterials (such as carbon nanotubes, graphene, highly ordered mesoporous carbons, and electron cyclotron resonance sputtered nanocarbon film) as nanoscale electrocatalysts (i.e., nanoelectrocatalysts) for constructing the catalytic nanointerfaces of electronic devices to achievemore » high-sensitivity and high-selectivity electrochemical sensors. Furthermore, different mechanisms for the extraordinary and unique electrocatalytic activities of these carbon nanomaterials will be also highlighted, compared and discussed. An outlook on the future trends and developments in this area will be provided at the end. Notably, to elaborate the nature of carbon nanomaterial, we will mainly focus on the electrocatalysis of single kind of carbon materials rather than their hybrid composite materials. As a result, we expect that advanced carbon nanomaterials with unique electrocatalytic activities will continue to attract increasing research interest and lead to new opportunities in various fields of research.« less

Electrocatalytic interface based on novel carbon nanomaterials for advanced electrochemical sensors

DOE Office of Scientific and Technical Information (OSTI.GOV)

Zhou, Ming; Guo, Shaojun

The rapid development of nanoscience and nanotechnology provides new opportunities for the sustainable progress of nanoscale catalysts (i.e., nanocatalysts). The introduction of nanocatalysts into electronic devices implants their novel functions into electronic sensing systems, resulting in the testing of many advanced electrochemical sensors and the fabrication of some highly sensitive, selective, and stable sensing platforms. In this Review, we will summarize recent significant progress on exploring advanced carbon nanomaterials (such as carbon nanotubes, graphene, highly ordered mesoporous carbons, and electron cyclotron resonance sputtered nanocarbon film) as nanoscale electrocatalysts (i.e., nanoelectrocatalysts) for constructing the catalytic nanointerfaces of electronic devices to achievemore » high-sensitivity and high-selectivity electrochemical sensors. Furthermore, different mechanisms for the extraordinary and unique electrocatalytic activities of these carbon nanomaterials will be also highlighted, compared and discussed. An outlook on the future trends and developments in this area will be provided at the end. Notably, to elaborate the nature of carbon nanomaterial, we will mainly focus on the electrocatalysis of single kind of carbon materials rather than their hybrid composite materials. As a result, we expect that advanced carbon nanomaterials with unique electrocatalytic activities will continue to attract increasing research interest and lead to new opportunities in various fields of research.« less

Effect of cleaning procedures on the electrical properties of carbon nanotube transistors—A statistical study

DOE Office of Scientific and Technical Information (OSTI.GOV)

Tittmann-Otto, J., E-mail: jana.tittmann-otto@zfm.tu-chemnitz.de; Hermann, S.; Hartmann, M.

The interface between a carbon nanotube (CNT) and its environment can dramatically affect the electrical properties of CNT-based field-effect transistors (FETs). For such devices, the channel environment plays a significant role inducing doping or charge traps giving rise to hysteresis in the transistor characteristics. Thereby the fabrication process strongly determines the extent of those effects and the final device performance. In CNT-based devices obtained from dispersions, a proper individualization of the nanotubes is mandatory. This is generally realized by an ultrasonic treatment combined with surfactant molecules, which enwrap nanotubes forming micelle aggregates. To minimize impact on device performance, it ismore » of vital importance to consider post-deposition treatments for removal of surfactant molecules and other impurities. In this context, we investigated the effect of several wet chemical cleaning and thermal post treatments on the electrical characteristics as well as physical properties of more than 600 devices fabricated only by wafer-level compatible technologies. We observed that nitric acid and water treatments improved the maximum-current of devices. Additionally, we found that the ethanol treatment successfully lowered hysteresis in the transfer characteristics. The effect of the chemical cleaning procedures was found to be more significant on CNT-metal contacts than for the FET channels. Moreover, we investigated the effect of an additional thermal cleaning step under vacuum after the chemical cleaning, which had an exceptional impact on the hysteresis behavior including hysteresis reversal. The presence of surfactant molecules on CNT was evidenced by X-ray photoelectron and Raman spectroscopies. By identifying the role of surfactant molecules and assessing the enhancement of device performance as a direct consequence of several cleaning procedures, these results are important for the development of CNT-based electronics at the wafer-level.« less

Effect of cleaning procedures on the electrical properties of carbon nanotube transistors—A statistical study

NASA Astrophysics Data System (ADS)

Tittmann-Otto, J.; Hermann, S.; Kalbacova, J.; Hartmann, M.; Toader, M.; Rodriguez, R. D.; Schulz, S. E.; Zahn, D. R. T.; Gessner, T.

2016-03-01

The interface between a carbon nanotube (CNT) and its environment can dramatically affect the electrical properties of CNT-based field-effect transistors (FETs). For such devices, the channel environment plays a significant role inducing doping or charge traps giving rise to hysteresis in the transistor characteristics. Thereby the fabrication process strongly determines the extent of those effects and the final device performance. In CNT-based devices obtained from dispersions, a proper individualization of the nanotubes is mandatory. This is generally realized by an ultrasonic treatment combined with surfactant molecules, which enwrap nanotubes forming micelle aggregates. To minimize impact on device performance, it is of vital importance to consider post-deposition treatments for removal of surfactant molecules and other impurities. In this context, we investigated the effect of several wet chemical cleaning and thermal post treatments on the electrical characteristics as well as physical properties of more than 600 devices fabricated only by wafer-level compatible technologies. We observed that nitric acid and water treatments improved the maximum-current of devices. Additionally, we found that the ethanol treatment successfully lowered hysteresis in the transfer characteristics. The effect of the chemical cleaning procedures was found to be more significant on CNT-metal contacts than for the FET channels. Moreover, we investigated the effect of an additional thermal cleaning step under vacuum after the chemical cleaning, which had an exceptional impact on the hysteresis behavior including hysteresis reversal. The presence of surfactant molecules on CNT was evidenced by X-ray photoelectron and Raman spectroscopies. By identifying the role of surfactant molecules and assessing the enhancement of device performance as a direct consequence of several cleaning procedures, these results are important for the development of CNT-based electronics at the wafer-level.

Metal-Organic-Framework-Derived Dual Metal- and Nitrogen-Doped Carbon as Efficient and Robust Oxygen Reduction Reaction Catalysts for Microbial Fuel Cells.

PubMed

Tang, Haolin; Cai, Shichang; Xie, Shilei; Wang, Zhengbang; Tong, Yexiang; Pan, Mu; Lu, Xihong

2016-02-01

A new class of dual metal and N doped carbon catalysts with well-defined porous structure derived from metal-organic frameworks (MOFs) has been developed as a high-performance electrocatalyst for oxygen reduction reaction (ORR). Furthermore, the microbial fuel cell (MFC) device based on the as-prepared Ni/Co and N codoped carbon as air cathode catalyst achieves a maximum power density of 4335.6 mW m -2 and excellent durability.

Flexible and weaveable capacitor wire based on a carbon nanocomposite fiber.

PubMed

Ren, Jing; Bai, Wenyu; Guan, Guozhen; Zhang, Ye; Peng, Huisheng

2013-11-06

A flexible and weaveable electric double-layer capacitor wire is developed by twisting two aligned carbon nanotube/ordered mesoporous carbon composite fibers with remarkable mechanical and electronic properties as electrodes. This capacitor wire exhibits high specific capacitance and long life stability. Compared with the conventional planar structure, the capacitor wire is also lightweight and can be integrated into various textile structures that are particularly promising for portable and wearable electronic devices. © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Separation of Carbon Monoxide and Carbon Dioxide for Mars ISRU-Concepts

NASA Technical Reports Server (NTRS)

LeVan, M. Douglas; Finn, John E.; Sridhar, K. R.

2000-01-01

Solid oxide electrolyzers, such as electrolysis cells utilizing yttria-stabilized zirconia, can produce oxygen from Mars atmospheric carbon dioxide and reject carbon monoxide and unreacted carbon dioxide in a separate stream. The oxygen-production process has been shown to be far more efficient if the high-pressure, unreacted carbon dioxide can be separated and recycled back into the feed stream. Additionally, the mass of the adsorption compressor can be reduced. Also, the carbon monoxide by-product is a valuable fuel for space exploration and habitation, with applications from fuel cells to production of hydrocarbons and plastics. In our research, we will design, construct, and test an innovative, robust, low mass, low power separation device that can recover carbon dioxide and carbon monoxide for Mars ISRU. Such fundamental process technology, involving gas-solid phase separation in a reduced gravitational environment, will help to enable Human Exploration and Development of Space. The separation device will be scaled to operate with a CO2 sorption compressor and a zirconia electrolysis device built at the NASA Ames Research Center and the University of Arizona, respectively. In our research, we will design, construct, and test an innovative, robust, low mass, low power separation device that can recover carbon dioxide and carbon monoxide for Mars ISRU, Such fundamental process technology, involving gas-solid phase separation in a reduced gravitational environment, will help to enable Human Exploration and Development of Space. The separation device will be scaled to operate with a CO2 sorption compressor and a zirconia electrolysis device built at the NASA Ames Research Center and the University of Arizona, The separation device will be scaled to operate with a CO2 sorption compressor and a zirconia electrolysis device built at the NASA Ames Research Center and the University of Arizona, Research needs for the design shown are as follows: (1) The best adsorbent for the process must be determined. (2) Adsorption isotherms must be measured, both for pure components and mixtures. (3) Mathematical modeling must be performed to provide a solid framework for design. (4) The separation system must be constructed and tested. (5) System integration must be studied.

Increasing the thermal conductivity of silicone based fluids using carbon nanofibers

NASA Astrophysics Data System (ADS)

Vales-Pinzon, C.; Vega-Flick, A.; Pech-May, N. W.; Alvarado-Gil, J. J.; Medina-Esquivel, R. A.; Zambrano-Arjona, M. A.; Mendez-Gamboa, J. A.

2016-11-01

Heat transfer in silicone fluids loaded with high thermal conductivity carbon nanofibers was studied using photoacoustics and thermal wave resonator cavity. It is shown that heat transport depends strongly on volume fraction of carbon nanofibers; in particular, a low loading percentage is enough to obtain significant changes in thermal conductivity. Theoretical models were used to determine how heat transfer is affected by structural formations in the composite, such as packing fraction and aspect ratio (form factor) of carbon nanofiber agglomerates in the high viscosity fluid matrix. Our results may find practical applications in systems, in which the carbon nanofibers can facilitate heat dissipation in the electronic devices.

21 CFR 868.2480 - Cutaneous carbon dioxide (PcCO2) monitor.

Code of Federal Regulations, 2012 CFR

2012-04-01

... 21 Food and Drugs 8 2012-04-01 2012-04-01 false Cutaneous carbon dioxide (PcCO2) monitor. 868.2480 Section 868.2480 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES ANESTHESIOLOGY DEVICES Monitoring Devices § 868.2480 Cutaneous carbon dioxide (PcCO2) monitor. (a) Identification. A...

21 CFR 866.5200 - Carbonic anhydrase B and C immunological test system.

Code of Federal Regulations, 2010 CFR

2010-04-01

... HUMAN SERVICES (CONTINUED) MEDICAL DEVICES IMMUNOLOGY AND MICROBIOLOGY DEVICES Immunological Test Systems § 866.5200 Carbonic anhydrase B and C immunological test system. (a) Identification. A carbonic... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Carbonic anhydrase B and C immunological test...

Investigation of the medical applications of the unique biocarbons developed by NASA. [compatibility of percutaneous prosthetic carbon devices

NASA Technical Reports Server (NTRS)

Mooney, V.

1973-01-01

The biocompatibility of percutaneous endoskeletal fixation devices made from carbon compounds, and their applications are considered. The clinical application of these carbons to solve human problems is demonstrated and the nature of myoelectric simulation by carbon implants is studied.

21 CFR 884.1300 - Uterotubal carbon dioxide insufflator and accessories.

Code of Federal Regulations, 2010 CFR

2010-04-01

... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Uterotubal carbon dioxide insufflator and... Gynecological Diagnostic Devices § 884.1300 Uterotubal carbon dioxide insufflator and accessories. (a) Identification. A uterotubal carbon dioxide insufflator and accessories is a device used to test the patency...

21 CFR 884.1300 - Uterotubal carbon dioxide insufflator and accessories.

Code of Federal Regulations, 2013 CFR

2013-04-01

... 21 Food and Drugs 8 2013-04-01 2013-04-01 false Uterotubal carbon dioxide insufflator and... Gynecological Diagnostic Devices § 884.1300 Uterotubal carbon dioxide insufflator and accessories. (a) Identification. A uterotubal carbon dioxide insufflator and accessories is a device used to test the patency...

21 CFR 884.1300 - Uterotubal carbon dioxide insufflator and accessories.

Code of Federal Regulations, 2014 CFR

2014-04-01

... 21 Food and Drugs 8 2014-04-01 2014-04-01 false Uterotubal carbon dioxide insufflator and... Gynecological Diagnostic Devices § 884.1300 Uterotubal carbon dioxide insufflator and accessories. (a) Identification. A uterotubal carbon dioxide insufflator and accessories is a device used to test the patency...

Recent applications of carbon-based nanomaterials in analytical chemistry: critical review.

PubMed

Scida, Karen; Stege, Patricia W; Haby, Gabrielle; Messina, Germán A; García, Carlos D

2011-04-08

The objective of this review is to provide a broad overview of the advantages and limitations of carbon-based nanomaterials with respect to analytical chemistry. Aiming to illustrate the impact of nanomaterials on the development of novel analytical applications, developments reported in the 2005-2010 period have been included and divided into sample preparation, separation, and detection. Within each section, fullerenes, carbon nanotubes, graphene, and composite materials will be addressed specifically. Although only briefly discussed, included is a section highlighting nanomaterials with interesting catalytic properties that can be used in the design of future devices for analytical chemistry. Copyright © 2011 Elsevier B.V. All rights reserved.

Molecular switches in carbon-rich organometallic compounds: Theoretical aspects

NASA Astrophysics Data System (ADS)

Costuas, Karine

2015-01-01

Organometallic complexes associated with an appropriate choice of ancillary ligands reveal to have a wide range of physical properties leading to promising applications when incorporated in nano-size devices. The challenge is to design innovative multifunctional compounds based on redox active carbon-rich organometallics associated with spin carriers and/or photochromic units. A multidisciplinary approach in this area has proved to be efficient in a series a systems combining carbon-rich bridging ligands and redox metallic moieties. In this domain, the role of theoretical investigations based on quantum mechanics tools have a crucial role in rationalizing and in helping designing systems possessing target properties.

Recent Applications of Carbon-Based Nanomaterials in Analytical Chemistry: Critical Review

PubMed Central

Scida, Karen; Stege, Patricia W.; Haby, Gabrielle; Messina, Germán A.; García, Carlos D.

2011-01-01

The objective of this review is to provide a broad overview of the advantages and limitations of carbon-based nanomaterials with respect to analytical chemistry. Aiming to illustrate the impact of nanomaterials on the development of novel analytical applications, developments reported in the 2005–2010 period have been included and divided into sample preparation, separation, and detection. Within each section, fullerenes, carbon nanotubes, graphene, and composite materials will be addressed specifically. Although only briefly discussed, included is a section highlighting nanomaterials with interesting catalytic properties that can be used in the design of future devices for analytical chemistry. PMID:21458626

Silicon carbidonitride based phosphors and lighting devices using the same

DOEpatents

Li, Yuanqiang; Romanelli, Michael Dennis; Tian, Yongchi

2013-09-17

Disclosed herein are novel families of silicon carbidonitride phosphor compositions. In certain embodiments, optimal ranges of carbon content have been identified which provide excellent luminescence and thermal stability characteristics.

Interface engineering to enhance the efficiency of conventional polymer solar cells by alcohol-/water-soluble C60 materials doped with alkali carbonates.

PubMed

Lai, Yu-Ying; Shih, Ping-I; Li, Yi-Peng; Tsai, Che-En; Wu, Jhong-Sian; Cheng, Yen-Ju; Hsu, Chain-Shu

2013-06-12

Two new C60-based n-type materials, EGMC-OH and EGMC-COOH, functionalized with hydrophilic triethylene glycol groups (TEGs), have been synthesized and employed in conventional polymer solar cells. With the assistance of the TEG-based surfactant, EGMC-OH and EGMC-COOH can be dissolved in highly polar solvents to implement the polar/nonpolar orthogonal solvent strategy, forming an electron modification layer (EML) without eroding the underlying active layer. Multilayer conventional solar cells on the basis of ITO/PEDOT:PSS/P3HT:PC61BM/EML/Ca/Al configuration with the insertion of the EGMC-OH and EGMC-COOH EML between the active layer and the electrode have thus been successfully realized by cost-effective solution processing techniques. Moreover, the electron conductivity of the EML can be improved by incorporating alkali carbonates into the EGMC-COOH EML. Compared to the pristine device with a PCE of 3.61%, the devices modified by the Li2CO3-doped EGMC-COOH EML achieved a highest PCE of 4.29%. Furthermore, we demonstrated that the formation of the EGMC-COOH EML can be utilized as a general approach in the fabrication of highly efficient multilayer conventional devices. With the incorporation of the EGMC-COOH doped with 40 wt % Li2CO3, the PCDCTBT-C8:PC71BM-based device exhibited a superior PCE of 4.51%, which outperformed the corresponding nonmodified device with a PCE of 3.63%.

A carbon-air battery for high power generation.

PubMed

Yang, Binbin; Ran, Ran; Zhong, Yijun; Su, Chao; Tadé, Moses O; Shao, Zongping

2015-03-16

We report a carbon-air battery for power generation based on a solid-oxide fuel cell (SOFC) integrated with a ceramic CO2-permeable membrane. An anode-supported tubular SOFC functioned as a carbon fuel container as well as an electrochemical device for power generation, while a high-temperature CO2-permeable membrane composed of a CO3(2-) mixture and an O(2-) conducting phase (Sm(0.2)Ce(0.8)O(1.9)) was integrated for in situ separation of CO2 (electrochemical product) from the anode chamber, delivering high fuel-utilization efficiency. After modifying the carbon fuel with a reverse Boudouard reaction catalyst to promote the in situ gasification of carbon to CO, an attractive peak power density of 279.3 mW cm(-2) was achieved for the battery at 850 °C, and a small stack composed of two batteries can be operated continuously for 200 min. This work provides a novel type of electrochemical energy device that has a wide range of application potentials. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

The effect of the geometry and material properties of a carbon joint produced by electron beam induced deposition on the electrical resistance of a multiwalled carbon nanotube-to-metal contact interface

NASA Astrophysics Data System (ADS)

Rykaczewski, Konrad; Henry, Matthew R.; Kim, Song-Kil; Fedorov, Andrei G.; Kulkarni, Dhaval; Singamaneni, Srikanth; Tsukruk, Vladimir V.

2010-01-01

Multiwall carbon nanotubes (MWNTs) are promising candidates for yielding next generation electrical and electronic devices such as interconnects and tips for conductive force microscopy. One of the main challenges in MWNT implementation in such devices is the high contact resistance of the MWNT-metal electrode interface. Electron beam induced deposition (EBID) of an amorphous carbon interface has previously been demonstrated to simultaneously lower the electrical contact resistance and improve the mechanical characteristics of the MWNT-electrode connection. In this work, we investigate the influence of process parameters, such as the electron beam energy, current, geometry, and deposition time, on the EBID-made carbon joint geometry and electrical contact resistance. The influence of the composition of the deposited material on its resistivity is also investigated. The relative importance of each component of the contact resistance and the limiting factor of the overall electrical resistance of a MWNT-based interconnect is determined through a combination of a model analysis and comprehensive experiments.

Carbon Nanofibrous Materials from Electrospinning: Preparation and Energy Applications

NASA Astrophysics Data System (ADS)

Aboagye, Alex

Carbon nanofibers with diameters that fall into submicron and nanometer range have attracted growing attention in recent years due to their superior chemical, electrical, and mechanical properties in combination with their unique one-dimensional nanostructures. Unlike catalytic synthesis, electrospinning polyacrylonitrile (PAN) followed by stabilization and carbonization has become a straightforward and convenient route to make continuous carbon nanofibers. The overall objective of this research was the design and production fiber based carbon nanomaterials, investigation of their structures and use in functional applications. Specifically, these carbon nanofibrous materials were employed as electrode material for energy storage and conversion devices such as dye sensitized solar cells and supercapacitors Morphology and structure of the carbon nanofibrous materials were investigated and their performance in corresponding applications were evaluated.

Multi-layer carbon-based coatings for field emission

DOEpatents

Sullivan, John P.; Friedmann, Thomas A.

1998-01-01

A multi-layer resistive carbon film field emitter device for cold cathode field emission applications. The multi-layered film of the present invention consists of at least two layers of a conductive carbon material, preferably amorphous-tetrahedrally coordinated carbon, where the resistivities of adjacent layers differ. For electron emission from the surface, the preferred structure can be a top layer having a lower resistivity than the bottom layer. For edge emitting structures, the preferred structure of the film can be a plurality of carbon layers, where adjacent layers have different resistivities. Through selection of deposition conditions, including the energy of the depositing carbon species, the presence or absence of certain elements such as H, N, inert gases or boron, carbon layers having desired resistivities can be produced.

Carbon nanotube switches for memory, RF communications and sensing applications, and methods of making the same

NASA Technical Reports Server (NTRS)

Kaul, Anupama B. (Inventor); Wong, Eric W. (Inventor); Baron, Richard L. (Inventor); Epp, Larry (Inventor)

2008-01-01

Switches having an in situ grown carbon nanotube as an element thereof, and methods of fabricating such switches. A carbon nanotube is grown in situ in mechanical connection with a conductive substrate, such as a heavily doped silicon wafer or an SOI wafer. The carbon nanotube is electrically connected at one location to a terminal. At another location of the carbon nanotube there is situated a pull electrode that can be used to elecrostatically displace the carbon nanotube so that it selectively makes contact with either the pull electrode or with a contact electrode. Connection to the pull electrode is sufficient to operate the device as a simple switch, while connection to a contact electrode is useful to operate the device in a manner analogous to a relay. In various embodiments, the devices disclosed are useful as at least switches for various signals, multi-state memory, computational devices, and multiplexers.

Core-shell heterojunction of silicon nanowire arrays and carbon quantum dots for photovoltaic devices and self-driven photodetectors.

PubMed

Xie, Chao; Nie, Biao; Zeng, Longhui; Liang, Feng-Xia; Wang, Ming-Zheng; Luo, Linbao; Feng, Mei; Yu, Yongqiang; Wu, Chun-Yan; Wu, Yucheng; Yu, Shu-Hong

2014-04-22

Silicon nanostructure-based solar cells have lately intrigued intensive interest because of their promising potential in next-generation solar energy conversion devices. Herein, we report a silicon nanowire (SiNW) array/carbon quantum dot (CQD) core-shell heterojunction photovoltaic device by directly coating Ag-assisted chemical-etched SiNW arrays with CQDs. The heterojunction with a barrier height of 0.75 eV exhibited excellent rectifying behavior with a rectification ratio of 10(3) at ±0.8 V in the dark and power conversion efficiency (PCE) as high as 9.10% under AM 1.5G irradiation. It is believed that such a high PCE comes from the improved optical absorption as well as the optimized carrier transfer and collection capability. Furthermore, the heterojunction could function as a high-performance self-driven visible light photodetector operating in a wide switching wavelength with good stability, high sensitivity, and fast response speed. It is expected that the present SiNW array/CQD core-shell heterojunction device could find potential applications in future high-performance optoelectronic devices.

Artificial leaf device for solar fuel production.

PubMed

Amao, Yutaka; Shuto, Naho; Furuno, Kana; Obata, Asami; Fuchino, Yoshiko; Uemura, Keiko; Kajino, Tsutomu; Sekito, Takeshi; Iwai, Satoshi; Miyamoto, Yasushi; Matsuda, Masatoshi

2012-01-01

Solar fuels, such as hydrogen gas produced from water and methanol produced from carbon dioxide reduction by artificial photosynthesis, have received considerable attention. In natural leaves the photosynthetic proteins are well-organized in the thylakoid membrane. To develop an artificial leaf device for solar low-carbon fuel production from CO2, a chlorophyll derivative chlorin-e6 (Chl-e6; photosensitizer), 1-carboxylundecanoyl-1'-methyl-4,4'-bipyrizinium bromide, iodide (CH3V(CH2)9COOH; the electron carrier) and formate dehydrogenase (FDH) (the catalyst) immobilised onto a silica-gel-based thin layer chromatography plate (the Chl-V-FDH device) was investigated. From luminescence spectroscopy measurements, the photoexcited triplet state of Chl-e6 was quenched by the CH3V(CH2)9COOH moiety on the device, indicating the photoinduced electron transfer from the photoexcited triplet state of Chl-e6 to the CH3V(CH2)9COOH moiety. When the CO2-saturated sample solution containing NADPH (the electron donor) was flowed onto the Chl-V-FDH device under visible light irradiation, the formic acid concentration increased with increasing irradiation time.

Integration of Multiple Components in Polystyrene-based Microfluidic Devices Part 1: Fabrication and Characterization

PubMed Central

Johnson, Alicia S.; Anderson, Kari B.; Halpin, Stephen T.; Kirkpatrick, Douglas C.; Spence, Dana M.; Martin, R. Scott

2012-01-01

In Part I of a two-part series, we describe a simple, and inexpensive approach to fabricate polystyrene devices that is based upon melting polystyrene (from either a Petri dish or powder form) against PDMS molds or around electrode materials. The ability to incorporate microchannels in polystyrene and integrate the resulting device with standard laboratory equipment such as an optical plate reader for analyte readout and micropipettors for fluid propulsion is first described. A simple approach for sample and reagent delivery to the device channels using a standard, multi-channel micropipette and a PDMS-based injection block is detailed. Integration of the microfluidic device with these off-chip functions (sample delivery and readout) enables high throughput screens and analyses. An approach to fabricate polystyrene-based devices with embedded electrodes is also demonstrated, thereby enabling the integration of microchip electrophoresis with electrochemical detection through the use of a palladium electrode (for a decoupler) and carbon-fiber bundle (for detection). The device was sealed against a PDMS-based microchannel and used for the electrophoretic separation and amperometric detection of dopamine, epinephrine, catechol, and 3,4-dihydroxyphenylacetic acid. Finally, these devices were compared against PDMS-based microchips in terms of their optical transparency and absorption of an anti-platelet drug, clopidogrel. Part I of this series lays the foundation for Part II, where these devices were utilized for various on-chip cellular analysis. PMID:23120747

Towards end to end technology modeling: Carbon nanotube and thermoelectric devices

NASA Astrophysics Data System (ADS)

Salamat, Shuaib

The goal of this work is to demonstrate the feasibility of end-to-end ("atoms to applications") technology modeling. Two different technologies were selected to drive this work. The first technology is carbon nanotube field-effect transistors (CNTFETs), and the goal is to model device level variability and identify the origin of variations in these devices. Recently, there has been significant progress in understanding the physics of carbon nanotube electronic devices and in identifying their potential applications. For nanotubes, the carrier mobility is high, so low bias transport across several hundred nanometers is nearly ballistic, and the deposition of high-k gate dielectrics does not degrade the carrier mobility. The conduction and valence bands are symmetric (useful for complimentary application) and the bandstructure is direct (enables optical emission). Because of these striking features, carbon nanotubes (CNTs) have received much attention. Carbon nanotubes field-effect transistors (CNTFETs) are one of the main potential candidates for large-area electronics. In this research model, systematic simulation approaches are applied to understand the intrinsic performance variability in CNTFETs. It is shown that control over diameter distribution is critically important process parameter for attaining high performance transistors and circuits with characteristics rivaling those of state-of-the-art Si technology. The second technology driver concerns the development of a multi-scale framework for thermoelectric device design. An essential step in the development of new materials and devices for thermoelectrics is to develop accurate, efficient, and realistic models. The ready availability of user friendly ab-initio codes and the ever-increasing computing power have made the band structure calculations routine. Thermoelectric device design, however, is still largely done at the effective mass level. Tools that allow device designers to make use of sophisticated electronic structure and phonon dispersion calculations are needed. We have developed a proof-of-concept, integrated, multi-scale design framework for TE technology. Beginning from full electronic and phonon dispersions, Landauer approach is used to evaluate the temperature-dependent thermoelectric transport parameters needed for device simulation. A comprehensive SPICE-based model for electro-thermal transport has also been developed to serve as a bridge between the materials and device level descriptions and the system level simulations. This prototype framework has been used to design a thermoelectric cooler for managing hot spots in the integrated circuit chips. What's more, as a byproduct of this research a suite of educational and simulation resources have been developed and deployed, on the nanoHUB.org science gateway to serve as a resource for the TE community.

Direct and Dry Deposited Single-Walled Carbon Nanotube Films Doped with MoO(x) as Electron-Blocking Transparent Electrodes for Flexible Organic Solar Cells.

PubMed

Jeon, Il; Cui, Kehang; Chiba, Takaaki; Anisimov, Anton; Nasibulin, Albert G; Kauppinen, Esko I; Maruyama, Shigeo; Matsuo, Yutaka

2015-07-01

Organic solar cells have been regarded as a promising electrical energy source. Transparent and conductive carbon nanotube film offers an alternative to commonly used ITO in photovoltaics with superior flexibility. This communication reports carbon nanotube-based indium-free organic solar cells and their flexible application. Direct and dry deposited carbon nanotube film doped with MoO(x) functions as an electron-blocking transparent electrode, and its performance is enhanced further by overcoating with PSS. The single-walled carbon nanotube organic solar cell in this work shows a power conversion efficiency of 6.04%. This value is 83% of the leading ITO-based device performance (7.48%). Flexible application shows 3.91% efficiency and is capable of withstanding a severe cyclic flex test.

Self-assembled three-dimensional and compressible interdigitated thin-film supercapacitors and batteries

PubMed Central

Nyström, Gustav; Marais, Andrew; Karabulut, Erdem; Wågberg, Lars; Cui, Yi; Hamedi, Mahiar M.

2015-01-01

Traditional thin-film energy-storage devices consist of stacked layers of active films on two-dimensional substrates and do not exploit the third dimension. Fully three-dimensional thin-film devices would allow energy storage in bulk materials with arbitrary form factors and with mechanical properties unique to bulk materials such as compressibility. Here we show three-dimensional energy-storage devices based on layer-by-layer self-assembly of interdigitated thin films on the surface of an open-cell aerogel substrate. We demonstrate a reversibly compressible three-dimensional supercapacitor with carbon nanotube electrodes and a three-dimensional hybrid battery with a copper hexacyanoferrate ion intercalating cathode and a carbon nanotube anode. The three-dimensional supercapacitor shows stable operation over 400 cycles with a capacitance of 25 F g−1 and is fully functional even at compressions up to 75%. Our results demonstrate that layer-by-layer self-assembly inside aerogels is a rapid, precise and scalable route for building high-surface-area 3D thin-film devices. PMID:26021485

Conducting polymer functionalized single-walled carbon nanotube based chemiresistive biosensor for the detection of human cardiac myoglobin

DOE Office of Scientific and Technical Information (OSTI.GOV)

Puri, Nidhi; Department of Physics, Faculty of Natural Sciences, Jamia Millia Islamia, New Delhi 110025; Niazi, Asad

2014-10-13

We report the fabrication of a single-walled carbon nanotube (SWNT) based ultrasensitive label-free chemiresistive biosensor for the detection of human cardiac biomarker, myoglobin (Ag-cMb). Poly(pyrrole-co-pyrrolepropylic acid) with pendant carboxyl groups was electrochemically deposited on electrophoretically aligned SWNT channel, as a conducting linker, for biomolecular immobilization of highly specific cardiac myoglobin antibody. The device was characterized by scanning electron microscopy, source-drain current-voltage (I-V), and charge-transfer characteristic studies. The device exhibited a linear response with a change in conductance in SWNT channel towards the target, Ag-cMb, over the concentration range of 1.0 to 1000 ng ml{sup −1} with a sensitivity of ∼118% per decademore » with high specificity.« less

Ionic liquid-functionalized carbon nanoparticles-modified cathode for efficiency enhancement in polymer solar cells

NASA Astrophysics Data System (ADS)

Chen, Xiaohong; Yang, Jiaxiang; Lu, Jiong; Manga, Kiran Kumar; Loh, Kian Ping; Zhu, Furong

2009-09-01

The power conversion efficiency (PCE) of regioregular poly(3-hexylthiophene) (P3HT) and {6,6}-phenyl C61-butyric acid methylester (PCBM)-based polymer solar cells was increased using an ionic liquid-functionalized carbon nanoparticles (ILCNs) thin film-modified cathode. The PCE of P3HT:PCBM based-polymer solar cells with a conventional aluminum (Al)-only cathode was increased by 20%-30% when the identical devices were made with an ILCNs-modified Al cathode, but its PCE was 10% lower than that of devices with LiF/Al cathode, measured under AM1.5G illumination of 100 mW/cm2. The ILCN interlayer approach, however, offers practical advantages to LiF in terms of its solution-processability, which is compatible with low cost, large area, and flexible solar cell fabrication.

Energy Dissipation and Transport in Carbon Nanotube Devices

NASA Astrophysics Data System (ADS)

Pop, Eric

2011-03-01

Power consumption is a significant challenge in electronics, often limiting the performance of integrated circuits from mobile devices to massive data centers. Carbon nanotubes have emerged as potentially energy-efficient future devices and interconnects, with both large mobility and thermal conductivity. This talk will focus on understanding and controlling energy dissipation [1-3] and transport [4-6] in carbon nanotubes, with applications to low-energy devices, interconnects, heat sinks, and memory elements. Experiments have been used to gain new insight into the fundamental behavior of such devices, and to better inform practical device models. The results suggest much room for energy optimization in nanoelectronics through the design of geometry, interfaces, and materials..

Application of biomass-derived flexible carbon cloth coated with MnO2 nanosheets in supercapacitors

NASA Astrophysics Data System (ADS)

He, Shuijian; Chen, Wei

2015-10-01

Successful application of inexpensive energy storage devices lies in the exploitation of fabrication approaches that are based on cost-efficient materials and that can be easily scaled up. Here, inexpensive textile weaved by natural flax fiber is selected as raw material in preparing flexible and binder-free electrode material for supercapacitors. Although carbon fiber cloth obtained from the direct carbonization of flax textile exhibits a low specific capacitance of 0.78 F g-1, carbon fiber cloth electrode shows a very short relaxation time of 39.1 m s and good stability with almost 100% capacitance retaining after 104 cycles at 5 A g-1. To extend the application of the resulting carbon cloth in supercapacitor field, a layer of MnO2 nanosheets is deposited on the surface of carbon fiber via in situ redox reaction between carbon and KMnO4. The specific capacitance of MnO2 reaches 683.73 F g-1 at 2 A g-1 and still retains 269.04 F g-1 at 300 A g-1, indicating the excellent rate capacitance performance of the carbon cloth/MnO2 hybrids. The present study shows that carbon cloth derived from flax textile can provide a low-cost material platform for the facile, cost-efficient and large scale fabrication of binder-free electrode materials for energy storage devices.

Heat dissipation for microprocessor using multiwalled carbon nanotubes based liquid.

PubMed

Hung Thang, Bui; Trinh, Pham Van; Chuc, Nguyen Van; Khoi, Phan Hong; Minh, Phan Ngoc

2013-01-01

Carbon nanotubes (CNTs) are one of the most valuable materials with high thermal conductivity (2000 W/m · K compared with thermal conductivity of Ag 419 W/m · K). This suggested an approach in applying the CNTs in thermal dissipation system for high power electronic devices, such as computer processor and high brightness light emitting diode (HB-LED). In this work, multiwalled carbon nanotubes (MWCNTs) based liquid was made by COOH functionalized MWCNTs dispersed in distilled water with concentration in the range between 0.2 and 1.2 gram/liter. MWCNT based liquid was used in liquid cooling system to enhance thermal dissipation for computer processor. By using distilled water in liquid cooling system, CPU's temperature decreases by about 10°C compared with using fan cooling system. By using MWCNT liquid with concentration of 1 gram/liter MWCNTs, the CPU's temperature decreases by 7°C compared with using distilled water in cooling system. Theoretically, we also showed that the presence of MWCNTs reduced thermal resistance and increased the thermal conductivity of liquid cooling system. The results have confirmed the advantages of the MWCNTs for thermal dissipation systems for the μ -processor and other high power electronic devices.

Competing Photocurrent Mechanisms in Quasi-Metallic Carbon Nanotube pn Devices.

PubMed

Amer, Moh R; Chang, Shun-Wen; Cronin, Stephen B

2015-07-01

Photodetectors based on quasi-metallic carbon nanotubes exhibit unique optoelectronic properties. Due to their small bandgap, photocurrent generation is possible at room temperature. The origin of this photocurrent is investigated to determine the underlying mechanism, which can be photothermoelectric effect or photovoltaic effect, depending on the bandgap magnitude of the quasi-metallic nanotube. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Thermal energy harvesting and solar energy conversion utilizing carbon-based nanomaterials

NASA Astrophysics Data System (ADS)

McCarthy, Patrick T.

This dissertation provides details of carbon-based nanomaterial fabrication for applications in energy harvesting and generation. As energy demands increase, and concerns about mankind's environmental impact increase, alternative methods of generating energy will be widely researched. Carbon-based nanomaterials may be effective in such applications as their fabrication is often inexpensive and they have highly desirable electrical, mechanical, and thermal properties. Synthesis and characterization of carbon nanotube thermal interfaces on gadolinium foils is described herein. Total thermal interface resistances of carbon nanotube coated gadolinium were measured using a one-dimensional reference calorimeter technique, and the effect of hydrogen embrittlement on the magnetic properties of gadolinium foils is discussed. The samples generated in this study were consistently measured with reduced total thermal interface resistances of 55-70% compared to bare gadolinium. Characterization of gadolinium foils in a cooling device called a magneto thermoelectric generator was also performed. A gadolinium shuttle drives the device as it transitions between ferromagnetic and paramagnetic states. Reduced interface resistances from the carbon nanotube arrays led to increased shuttle frequency and effective heat transfer coefficients. Detailed theoretical derivations for electron emission during thermal and photo-excitation are provided for both three-dimensional and two-dimensional materials. The derived theories were fitted to experimental data from variable temperature photoemission studies of potassium-intercalated graphitic nanopetals. A work function reduction from approximately 4.5 eV to 2 -- 3 eV resulted from potassium intercalation and adsorption. While changes in the electron energy distribution shape and intensity were significant within 310 -- 680 K, potassium-intercalated graphitic petals demonstrate very high thermal stability after heating to nearly 1000 K. Boron nitride modification of the nanopetals was performed in an effort to minimize deintercalation of potassium from the nanopetal lattice and while multiple work functions were present within the electron energy distribution, massive reductions in emission intensity took place above 580 K. Finally, a device for measuring the current density during photoemission was also developed and photoemission induced by a solar simulator at room temperature produced currents on the order of 1 nA/cm 2 resulting in a quantum efficiency of approximately 8.0x10 --8 electrons emitted per photon of illumination.

Nanoporous carbon-based electrodes for high strain ionomeric bending actuators

NASA Astrophysics Data System (ADS)

Palmre, Viljar; Brandell, Daniel; Mäeorg, Uno; Torop, Janno; Volobujeva, Olga; Punning, Andres; Johanson, Urmas; Kruusmaa, Maarja; Aabloo, Alvo

2009-09-01

Ionic polymer metal composites (IPMCs) are electroactive material devices that bend at low applied voltage (1-4 V). Inversely, a voltage is generated when the materials are deformed, which makes them useful both as sensors and actuators. In this paper, we propose two new highly porous carbon materials as electrodes for IPMC actuators, generating a high specific area, and compare their electromechanical performance with recently reported RuO2 electrodes and conventional IPMCs. Using a direct assembly process (DAP), we synthesize ionic liquid (Emi-Tf) actuators with either carbide-derived carbon (CDC) or coconut-shell-based activated carbon-based electrodes. The carbon electrodes were applied onto ionic liquid-swollen Nafion membranes using a direct assembly process. The study demonstrates that actuators based on carbon electrodes derived from TiC have the greatest peak-to-peak strain output, reaching up to 20.4 mɛ (equivalent to>2%) at a 2 V actuation signal, exceeding that of the RuO2 electrodes by more than 100%. The electrodes synthesized from TiC-derived carbon also exhibit significantly higher maximum strain rate. The differences between the materials are discussed in terms of molecular interactions and mechanisms upon actuation in the different electrodes.

40 CFR 60.695 - Monitoring of operations.

Code of Federal Regulations, 2010 CFR

2010-07-01

... device outlet gas stream or inlet and outlet gas stream shall be used. (i) For a carbon adsorption system... adsorption system that does not regenerate the carbon bed directly onsite in the control device (e.g., a... carbon adsorption system shall be monitored on a regular schedule, and the existing carbon shall be...

40 CFR 60.695 - Monitoring of operations.

Code of Federal Regulations, 2011 CFR

2011-07-01

... device outlet gas stream or inlet and outlet gas stream shall be used. (i) For a carbon adsorption system... adsorption system that does not regenerate the carbon bed directly onsite in the control device (e.g., a... carbon adsorption system shall be monitored on a regular schedule, and the existing carbon shall be...

Electrical contacts to individual SWCNTs: A review

PubMed Central

Hierold, Christofer; Haluska, Miroslav

2014-01-01

Summary Owing to their superior electrical characteristics, nanometer dimensions and definable lengths, single-walled carbon nanotubes (SWCNTs) are considered as one of the most promising materials for various types of nanodevices. Additionally, they can be used as either passive or active elements. To be integrated into circuitry or devices, they are typically connected with metal leads to provide electrical contacts. The properties and quality of these electrical contacts are important for the function and performance of SWCNT-based devices. Since carbon nanotubes are quasi-one-dimensional structures, contacts to them are different from those for bulk semiconductors. Additionally, some techniques used in Si-based technology are not compatible with SWCNT-based device fabrication, such as the contact area cleaning technique. In this review, an overview of the investigations of metal–SWCNT contacts is presented, including the principle of charge carrier injection through the metal–SWCNT contacts and experimental achievements. The methods for characterizing the electrical contacts are discussed as well. The parameters which influence the contact properties are summarized, mainly focusing on the contact geometry, metal type and the cleanliness of the SWCNT surface affected by the fabrication processes. Moreover, the challenges for widespread application of CNFETs are additionally discussed. PMID:25551048

40 CFR 63.993 - Absorbers, condensers, carbon adsorbers and other recovery devices used as final recovery devices.

Code of Federal Regulations, 2014 CFR

2014-07-01

... providing a continuous record or an integrating regeneration stream flow monitoring device having an accuracy of ±10 percent or better, capable of recording the total regeneration stream mass or volumetric flow for each regeneration cycle; and a carbon-bed temperature monitoring device, capable of recording...

40 CFR 63.993 - Absorbers, condensers, carbon adsorbers and other recovery devices used as final recovery devices.

Code of Federal Regulations, 2010 CFR

2010-07-01

... providing a continuous record or an integrating regeneration stream flow monitoring device having an accuracy of ±10 percent or better, capable of recording the total regeneration stream mass or volumetric flow for each regeneration cycle; and a carbon-bed temperature monitoring device, capable of recording...

40 CFR 63.993 - Absorbers, condensers, carbon adsorbers and other recovery devices used as final recovery devices.

Code of Federal Regulations, 2011 CFR

2011-07-01

... providing a continuous record or an integrating regeneration stream flow monitoring device having an accuracy of ±10 percent or better, capable of recording the total regeneration stream mass or volumetric flow for each regeneration cycle; and a carbon-bed temperature monitoring device, capable of recording...

40 CFR 63.993 - Absorbers, condensers, carbon adsorbers and other recovery devices used as final recovery devices.

Code of Federal Regulations, 2012 CFR

2012-07-01

... providing a continuous record or an integrating regeneration stream flow monitoring device having an accuracy of ±10 percent or better, capable of recording the total regeneration stream mass or volumetric flow for each regeneration cycle; and a carbon-bed temperature monitoring device, capable of recording...

40 CFR 63.993 - Absorbers, condensers, carbon adsorbers and other recovery devices used as final recovery devices.

Code of Federal Regulations, 2013 CFR

2013-07-01

... providing a continuous record or an integrating regeneration stream flow monitoring device having an accuracy of ±10 percent or better, capable of recording the total regeneration stream mass or volumetric flow for each regeneration cycle; and a carbon-bed temperature monitoring device, capable of recording...

40 CFR 65.152 - Carbon adsorbers used as control devices.

Code of Federal Regulations, 2011 CFR

2011-07-01

... control device. If an owner or operator elects to replace a control device on a Group 1 process vent or... 40 Protection of Environment 15 2011-07-01 2011-07-01 false Carbon adsorbers used as control... PROGRAMS (CONTINUED) CONSOLIDATED FEDERAL AIR RULE Closed Vent Systems, Control Devices, and Routing to a...

Peapod-like Li3 VO4 /N-Doped Carbon Nanowires with Pseudocapacitive Properties as Advanced Materials for High-Energy Lithium-Ion Capacitors.

PubMed

Shen, Laifa; Lv, Haifeng; Chen, Shuangqiang; Kopold, Peter; van Aken, Peter A; Wu, Xiaojun; Maier, Joachim; Yu, Yan

2017-07-01

Lithium ion capacitors are new energy storage devices combining the complementary features of both electric double-layer capacitors and lithium ion batteries. A key limitation to this technology is the kinetic imbalance between the Faradaic insertion electrode and capacitive electrode. Here, we demonstrate that the Li 3 VO 4 with low Li-ion insertion voltage and fast kinetics can be favorably used for lithium ion capacitors. N-doped carbon-encapsulated Li 3 VO 4 nanowires are synthesized through a morphology-inheritance route, displaying a low insertion voltage between 0.2 and 1.0 V, a high reversible capacity of ≈400 mAh g -1 at 0.1 A g -1 , excellent rate capability, and long-term cycling stability. Benefiting from the small nanoparticles, low energy diffusion barrier and highly localized charge-transfer, the Li 3 VO 4 /N-doped carbon nanowires exhibit a high-rate pseudocapacitive behavior. A lithium ion capacitor device based on these Li 3 VO 4 /N-doped carbon nanowires delivers a high energy density of 136.4 Wh kg -1 at a power density of 532 W kg -1 , revealing the potential for application in high-performance and long life energy storage devices. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Design rules and reality check for carbon-based ultracapacitors

NASA Astrophysics Data System (ADS)

Eisenmann, Erhard T.

1995-04-01

Design criteria for carbon-based Ultracapacitors have been determined for specified energy and power requirements, using the geometry of the components and such material properties as density, porosity and conductivity as parameters, while also considering chemical compatibility. This analysis shows that the weights of active and inactive components of the capacitor structure must be carefully balanced for maximum energy and power density. When applied to nonaqueous electrolytes, the design rules for a 5 Wh/kg device call for porous carbon with a specific capacitance of about 30 F/cu cm. This performance is not achievable with pure, electrostatic double layer capacitance. Double layer capacitance is only 5 to 30% of that observed in aqueous electrolyte. Tests also showed that nonaqueous electrolytes have a diminished capability to access micropores in activated carbon, in one case yielding a capacitance of less than 1 F/cu cm for carbon that had 100 F/cu cm in aqueous electrolyte. With negative results on nonaqueous electrolytes dominating the present study, the obvious conclusion is to concentrate on aqueous systems. Only aqueous double layer capacitors offer adequate electrostatic charging characteristics which is the basis for high power performance. There arc many opportunities for further advancing aqueous double layer capacitors, one being the use of highly activated carbon films, as opposed to powders, fibers and foams. While the manufacture of carbon films is still costly, and while the energy and power density of the resulting devices may not meet the optimistic goals that have been proposed, this technology could produce true double layer capacitors with significantly improved performance and large commercial potential.

Amorphous carbon for photovoltaics

NASA Astrophysics Data System (ADS)

Risplendi, Francesca; Grossman, Jeffrey C.

2015-03-01

All-carbon solar cells have attracted attention as candidates for innovative photovoltaic devices. Carbon-based materials such as graphene, carbon nanotubes (CNT) and amorphous carbon (aC) have the potential to present physical properties comparable to those of silicon-based materials with advantages such as low cost and higher thermal stability.In particular a-C structures are promising systems in which both sp2 and sp3 hybridization coordination are present in different proportions depending on the specific density, providing the possibility of tuning their optoelectronic properties and achieving comparable sunlight absorption to aSi. In this work we employ density functional theory to design suitable device architectures, such as bulk heterojunctions (BHJ) or pn junctions, consisting of a-C as the active layer material.Regarding BHJ, we study interfaces between aC and C nanostructures (such as CNT and fullerene) to relate their optoelectronic properties to the stoichiometry of aC. We demonstrate that the energy alignment between the a-C mobility edges and the occupied and unoccupied states of the CNT or C60 can be widely tuned by varying the aC density to obtain a type II interface.To employ aC in pn junctions we analyze the p- and n-type doping of a-C focusingon an evaluation of the Fermi level and work function dependence on doping.Our results highlight promising features of aC as the active layer material of thin-film solar cells.

New study on the correlation between carbon dioxide concentration in the environment and radon monitor devices.

PubMed

Shahrokhi, A; Burghele, B D; Fábián, F; Kovács, T

2015-12-01

The influence of high geogenic carbon dioxide concentrations on monitoring devices might present a significant challenge to the measurement of radon concentrations in environments with a high level of carbon dioxide concentration such as volcano sites, mofettes, caves, etc. In this study, the influence of carbon dioxide concentration on several different types of radon monitor devices - including Alpha Spectrometry (Sarad RTM 2200, EQF 3220, RAD7), Ionizing Chamber (AlphaGUARD PQ2000 PRO) and Active Cell (Active scintillation cell, Pylon 300A) - was examined to represent new aspects of radon measuring in environments with carbon dioxide. In light of the results, all measuring devices were exposed to variable conditions affected by carbon dioxide concentration, except for the AlphaGUARD, which was kept in a steady state throughout the experiment. It was observed that alpha spectroscopy devices were affected by carbon dioxide, since measured radon concentrations decreased in the presence of 70% and 90% carbon dioxide concentrations by 26.5 ± 2% and 14.5 ± 2.5% for EQF 3220, and 32 ± 2% and 35.5 ± 2% for RTM 2200. However, the ionizing chamber instrument was unaffected by changes in carbon dioxide concentration. It was determined that the RAD7 performed relatively inefficiently in the presence of carbon dioxide concentrations higher than 67% by an overall efficiency factor of approximately 0.52, confirming that it is not an admissible radon monitor instrument in environments with high carbon dioxide concentrations. Copyright © 2015 Elsevier Ltd. All rights reserved.

Ozone Sensing Based on Palladium Decorated Carbon Nanotubes

PubMed Central

Colindres, Selene Capula; Aguir, Khalifa; Sodi, Felipe Cervantes; Vargas, Luis Villa; Moncayo Salazar, José A.; Febles, Vicente Garibay

2014-01-01

Multiwall carbon nanotubes (MWCNTs) were easily and efficiently decorated with Pd nanoparticles through a vapor-phase impregnation-decomposition method starting from palladium acetylacetonates. The sensor device consisted on a film of sensitive material (MWCNTs-Pd) deposited by drop coating on platinum interdigitated electrodes on a SiO2 substrate. The sensor exhibited a resistance change to ozone (O3) with a response time of 60 s at different temperatures and the capability of detecting concentrations up to 20 ppb. The sensor shows the best response when exposed to O3 at 120 °C. The device shows a very reproducible sensor performance, with high repeatability, full recovery and efficient response. PMID:24736133

Impact of Tunnel-Barrier Strength on Magnetoresistance in Carbon Nanotubes

NASA Astrophysics Data System (ADS)

Morgan, Caitlin; Misiorny, Maciej; Metten, Dominik; Heedt, Sebastian; Schäpers, Thomas; Schneider, Claus M.; Meyer, Carola

2016-05-01

We investigate magnetoresistance in spin valves involving CoPd-contacted carbon nanotubes. Both the temperature and bias-voltage dependence clearly indicate tunneling magnetoresistance as the origin. We show that this effect is significantly affected by the tunnel-barrier strength, which appears to be one reason for the variation between devices previously detected in similar structures. Modeling the data by means of the scattering matrix approach, we find a nontrivial dependence of the magnetoresistance on the barrier strength. Furthermore, an analysis of the spin precession observed in a nonlocal Hanle measurement yields a spin lifetime of τs=1.1 ns , a value comparable with those found in silicon- or graphene-based spin-valve devices.

Glutamate biosensors based on diamond and graphene platforms.

PubMed

Hu, Jingping; Wisetsuwannaphum, Sirikarn; Foord, John S

2014-01-01

l-Glutamate is one of the most important neurotransmitters in the mammalian central nervous system, playing a vital role in many physiological processes and implicated in several neurological disorders, for which monitoring of dynamic levels of extracellular glutamate in the living brain tissues may contribute to medical understanding and treatments. Electrochemical sensing of glutamate has been developed recently mainly using platinum, carbon fibre and carbon nanotube electrodes. In the present work, we explore the fabrication and properties of electrochemical glutamate sensors fabricated on doped chemical vapour deposition diamond electrodes and graphene nanoplatelet structures. The sensors incorporate platinum nanoparticles to catalyse the electrooxidation of hydrogen peroxide, glutamate oxidase to oxidise glutamate, and a layer of poly-phenylenediamine to impart selectivity. The performance of the devices was compared to a similar sensor fabricated on glassy carbon. Both the diamond and the graphene sensor showed very competitive performance compared to the majority of existing electrochemical sensors. The graphene based sensor showed the best performance of the three investigated in terms of sensitivity, linear dynamic range and long term stability, whereas it was found that the diamond device showed the best limit of detection.

40 CFR 60.544 - Monitoring of operations.

Code of Federal Regulations, 2011 CFR

2011-07-01

... are used, or Michelin-B operation where a carbon adsorber is used to meet the performance requirements... organic solvent-based sprays are used, or Michelin-B operation where a VOC recovery device other than a...

40 CFR 60.544 - Monitoring of operations.

Code of Federal Regulations, 2013 CFR

2013-07-01

... are used, or Michelin-B operation where a carbon adsorber is used to meet the performance requirements... organic solvent-based sprays are used, or Michelin-B operation where a VOC recovery device other than a...

40 CFR 60.544 - Monitoring of operations.

Code of Federal Regulations, 2014 CFR

2014-07-01

... are used, or Michelin-B operation where a carbon adsorber is used to meet the performance requirements... organic solvent-based sprays are used, or Michelin-B operation where a VOC recovery device other than a...

40 CFR 60.544 - Monitoring of operations.

Code of Federal Regulations, 2012 CFR

2012-07-01

... are used, or Michelin-B operation where a carbon adsorber is used to meet the performance requirements... organic solvent-based sprays are used, or Michelin-B operation where a VOC recovery device other than a...

Label-free capture of breast cancer cells spiked in buffy coats using carbon nanotube antibody micro-arrays

NASA Astrophysics Data System (ADS)

Khosravi, Farhad; Trainor, Patrick; Rai, Shesh N.; Kloecker, Goetz; Wickstrom, Eric; Panchapakesan, Balaji

2016-04-01

We demonstrate the rapid and label-free capture of breast cancer cells spiked in buffy coats using nanotube-antibody micro-arrays. Single wall carbon nanotube arrays were manufactured using photo-lithography, metal deposition, and etching techniques. Anti-epithelial cell adhesion molecule (EpCAM) antibodies were functionalized to the surface of the nanotube devices using 1-pyrene-butanoic acid succinimidyl ester functionalization method. Following functionalization, plain buffy coat and MCF7 cell spiked buffy coats were adsorbed on to the nanotube device and electrical signatures were recorded for differences in interaction between samples. A statistical classifier for the ‘liquid biopsy’ was developed to create a predictive model based on dynamic time warping to classify device electrical signals that corresponded to plain (control) or spiked buffy coats (case). In training test, the device electrical signals originating from buffy versus spiked buffy samples were classified with ˜100% sensitivity, ˜91% specificity and ˜96% accuracy. In the blinded test, the signals were classified with ˜91% sensitivity, ˜82% specificity and ˜86% accuracy. A heatmap was generated to visually capture the relationship between electrical signatures and the sample condition. Confocal microscopic analysis of devices that were classified as spiked buffy coats based on their electrical signatures confirmed the presence of cancer cells, their attachment to the device and overexpression of EpCAM receptors. The cell numbers were counted to be ˜1-17 cells per 5 μl per device suggesting single cell sensitivity in spiked buffy coats that is scalable to higher volumes using the micro-arrays.

Solid-State Thin-Film Supercapacitors with Ultrafast Charge/Discharge Based on N-Doped-Carbon-Tubes/Au-Nanoparticles-Doped-MnO2 Nanocomposites.

PubMed

Lv, Qiying; Wang, Shang; Sun, Hongyu; Luo, Jun; Xiao, Jian; Xiao, JunWu; Xiao, Fei; Wang, Shuai

2016-01-13

Although carbonaceous materials possess long cycle stability and high power density, their low-energy density greatly limits their applications. On the contrary, metal oxides are promising pseudocapacitive electrode materials for supercapacitors due to their high-energy density. Nevertheless, poor electrical conductivity of metal oxides constitutes a primary challenge that significantly limits their energy storage capacity. Here, an advanced integrated electrode for high-performance pseudocapacitors has been designed by growing N-doped-carbon-tubes/Au-nanoparticles-doped-MnO2 (NCTs/ANPDM) nanocomposite on carbon fabric. The excellent electrical conductivity and well-ordered tunnels of NCTs together with Au nanoparticles of the electrode cause low internal resistance, good ionic contact, and thus enhance redox reactions for high specific capacitance of pure MnO2 in aqueous electrolyte, even at high scan rates. A prototype solid-state thin-film symmetric supercapacitor (SSC) device based on NCTs/ANPDM exhibits large energy density (51 Wh/kg) and superior cycling performance (93% after 5000 cycles). In addition, the asymmetric supercapacitor (ASC) device assembled from NCTs/ANPDM and Fe2O3 nanorods demonstrates ultrafast charge/discharge (10 V/s), which is among the best reported for solid-state thin-film supercapacitors with both electrodes made of metal oxide electroactive materials. Moreover, its superior charge/discharge behavior is comparable to electrical double layer type supercapacitors. The ASC device also shows superior cycling performance (97% after 5000 cycles). The NCTs/ANPDM nanomaterial demonstrates great potential as a power source for energy storage devices.

Highly Enhanced Raman Scattering on Carbonized Polymer Films.

PubMed

Yoon, Jong-Chul; Hwang, Jongha; Thiyagarajan, Pradheep; Ruoff, Rodney S; Jang, Ji-Hyun

2017-06-28

We have discovered a carbonized polymer film to be a reliable and durable carbon-based substrate for carbon enhanced Raman scattering (CERS). Commercially available SU8 was spin coated and carbonized (c-SU8) to yield a film optimized to have a favorable Fermi level position for efficient charge transfer, which results in a significant Raman scattering enhancement under mild measurement conditions. A highly sensitive CERS (detection limit of 10 -8 M) that was uniform over a large area was achieved on a patterned c-SU8 film and the Raman signal intensity has remained constant for 2 years. This approach works not only for the CMOS-compatible c-SU8 film but for any carbonized film with the correct composition and Fermi level, as demonstrated with carbonized-PVA (poly(vinyl alcohol)) and carbonized-PVP (polyvinylpyrollidone) films. Our study certainly expands the rather narrow range of Raman-active material platforms to include robust carbon-based films readily obtained from polymer precursors. As it uses broadly applicable and cheap polymers, it could offer great advantages in the development of practical devices for chemical/bio analysis and sensors.

High-cycle electromechanical aging of dielectric elastomer actuators with carbon-based electrodes

NASA Astrophysics Data System (ADS)

de Saint-Aubin, C. A.; Rosset, S.; Schlatter, S.; Shea, H.

2018-07-01

We present high-cycle aging tests of dielectric elastomer actuators (DEAs) based on silicone elastomers, reporting on the time-evolution of actuation strain and of electrode resistance over millions of cycles. We compare several types of carbon-based electrodes, and for the first time show how the choice of electrode has a dramatic influence on DEA aging. An expanding circle DEA configuration is used, consisting of a commercial silicone membrane with the following electrodes: commercial carbon grease applied manually, solvent-diluted carbon grease applied by stamping (pad printing), loose carbon black powder applied manually, carbon black powder suspension applied by inkjet-printing, and conductive silicone-carbon composite applied by stamping. The silicone-based DEAs with manually applied carbon grease electrodes show the shortest lifetime of less than 105 cycles at 5% strain, while the inkjet-printed carbon powder and the stamped silicone-carbon composite make for the most reliable devices, with lifetimes greater than 107 cycles at 5% strain. These results are valid for the specific dielectric and electrode configurations that were tested: using other dielectrics or electrode formulations would lead to different lifetimes and failure modes. We find that aging (as seen in the change in resistance and in actuation strain versus cycle number) is independent of the actuation frequency from 10 Hz to 200 Hz, and depends on the total accumulated time the DEA spends in an actuated state.

Mixtures of glyme and aprotic-protic ionic liquids as electrolytes for energy storage devices

NASA Astrophysics Data System (ADS)

Stettner, T.; Huang, P.; Goktas, M.; Adelhelm, P.; Balducci, A.

2018-05-01

Ionic liquids (ILs) have been proven to be promising electrolytes for electrochemical energy storage devices such as supercapacitors and lithium ion batteries. In the last years, due to deficiency in storage of lithium on earth, innovative systems, such as sodium-based devices, attracted considerable attention. IL-based electrolytes have been proposed also as electrolytes for these devices. Nevertheless, in the case of these systems, the advantages and limits of IL-based electrolytes need to be further investigated. In this work we report an investigation about the chemical-physical properties of mixtures containing bis(2-methoxyethyl)ether diglyme (2G), which is presently considered as one of the most interesting solvents for sodium-based devices, and the ionic liquids 1-butyl-1-methylpyrrolidinium bis(trifluoromethanesulfonyl)imide (Pyr14TFSI) and 1-butylpyrrolidinium bis(trifluoromethanesulfonyl)imide (PyrH4TFSI). The conductivities, viscosities, and densities of several mixtures of 2G and these ILs have been investigated. Furthermore, their impact on the electrochemical behaviour of activated carbon composite electrodes has been considered. The results of this investigation indicate that these mixtures are promising electrolytes for the realization of advanced sodium-based devices.

Efficient fabrication of carbon nanotube micro tip arrays by tailoring cross-stacked carbon nanotube sheets.

PubMed

Wei, Yang; Liu, Peng; Zhu, Feng; Jiang, Kaili; Li, Qunqing; Fan, Shoushan

2012-04-11

Carbon nanotube (CNT) micro tip arrays with hairpin structures on patterned silicon wafers were efficiently fabricated by tailoring the cross-stacked CNT sheet with laser. A blade-like structure was formed at the laser-cut edges of the CNT sheet. CNT field emitters, pulled out from the end of the hairpin by an adhesive tape, can provide 150 μA intrinsic emission currents with low beam noise. The nice field emission is ascribed to the Joule-heating-induced desorption of the emitter surface by the hairpin structure, the high temperature annealing effect, and the surface morphology. The CNT emitters with hairpin structures will greatly promote the applications of CNTs in vacuum electronic devices and hold the promises to be used as the hot tips for thermochemical nanolithography. More CNT-based structures and devices can be fabricated on a large scale by this versatile method. © 2012 American Chemical Society

High performance carbon nanocomposites for ultracapacitors

DOEpatents

Lu, Wen

2012-10-02

The present invention relates to composite electrodes for electrochemical devices, particularly to carbon nanotube composite electrodes for high performance electrochemical devices, such as ultracapacitors.

Modelling of thermal shock experiments of carbon based materials in JUDITH

NASA Astrophysics Data System (ADS)

Ogorodnikova, O. V.; Pestchanyi, S.; Koza, Y.; Linke, J.

2005-03-01

The interaction of hot plasma with material in fusion devices can result in material erosion and irreversible damage. Carbon based materials are proposed for ITER divertor armour. To simulate carbon erosion under high heat fluxes, electron beam heating in the JUDITH facility has been used. In this paper, carbon erosion under energetic electron impact is modeled by the 3D thermomechanics code 'PEGASUS-3D'. The code is based on a crack generation induced by thermal stress. The particle emission observed in thermal shock experiments is a result of breaking bonds between grains caused by thermal stress. The comparison of calculations with experimental data from JUDITH shows good agreement for various incident power densities and pulse durations. A realistic mean failure stress has been found. Pre-heating of test specimens results in earlier onset of brittle destruction and enhanced particle loss in agreement with experiments.

Toward all-carbon electronics: fabrication of graphene-based flexible electronic circuits and memory cards using maskless laser direct writing.

PubMed

Liang, Jiajie; Chen, Yongsheng; Xu, Yanfei; Liu, Zhibo; Zhang, Long; Zhao, Xin; Zhang, Xiaoliang; Tian, Jianguo; Huang, Yi; Ma, Yanfeng; Li, Feifei

2010-11-01

Owing to its extraordinary electronic property, chemical stability, and unique two-dimensional nanostructure, graphene is being considered as an ideal material for the highly expected all-carbon-based micro/nanoscale electronics. Herein, we present a simple yet versatile approach to constructing all-carbon micro/nanoelectronics using solution-processing graphene films directly. From these graphene films, various graphene-based microcosmic patterns and structures have been fabricated using maskless computer-controlled laser cutting. Furthermore, a complete system involving a prototype of a flexible write-once-read-many-times memory card and a fast data-reading system has been demonstrated, with infinite data retention time and high reliability. These results indicate that graphene could be the ideal material for fabricating the highly demanded all-carbon and flexible devices and electronics using the simple and efficient roll-to-roll printing process when combined with maskless direct data writing.

Stretchable carbon nanotube charge-trap floating-gate memory and logic devices for wearable electronics.

PubMed

Son, Donghee; Koo, Ja Hoon; Song, Jun-Kyul; Kim, Jaemin; Lee, Mincheol; Shim, Hyung Joon; Park, Minjoon; Lee, Minbaek; Kim, Ji Hoon; Kim, Dae-Hyeong

2015-05-26

Electronics for wearable applications require soft, flexible, and stretchable materials and designs to overcome the mechanical mismatch between the human body and devices. A key requirement for such wearable electronics is reliable operation with high performance and robustness during various deformations induced by motions. Here, we present materials and device design strategies for the core elements of wearable electronics, such as transistors, charge-trap floating-gate memory units, and various logic gates, with stretchable form factors. The use of semiconducting carbon nanotube networks designed for integration with charge traps and ultrathin dielectric layers meets the performance requirements as well as reliability, proven by detailed material and electrical characterizations using statistics. Serpentine interconnections and neutral mechanical plane layouts further enhance the deformability required for skin-based systems. Repetitive stretching tests and studies in mechanics corroborate the validity of the current approaches.

Multi-layer carbon-based coatings for field emission

DOEpatents

Sullivan, J.P.; Friedmann, T.A.

1998-10-13

A multi-layer resistive carbon film field emitter device for cold cathode field emission applications is disclosed. The multi-layered film of the present invention consists of at least two layers of a conductive carbon material, preferably amorphous-tetrahedrally coordinated carbon, where the resistivities of adjacent layers differ. For electron emission from the surface, the preferred structure can be a top layer having a lower resistivity than the bottom layer. For edge emitting structures, the preferred structure of the film can be a plurality of carbon layers, where adjacent layers have different resistivities. Through selection of deposition conditions, including the energy of the depositing carbon species, the presence or absence of certain elements such as H, N, inert gases or boron, carbon layers having desired resistivities can be produced. 8 figs.

Creating With Carbon

NASA Technical Reports Server (NTRS)

2003-01-01

A subsidiary of SI Diamond Technology, Inc., Applied Nanotech, of Austin, Texas, is creating a buzz among various technology firms and venture capital groups interested in the company s progressive research on carbon-related field emission devices, including carbon nanotubes, filaments of pure carbon less than one ten-thousandth the width of human hair. Since their discovery in 1991, carbon nanotubes have gained considerable attention due to their unique physical properties. For example, a single perfect carbon nanotube can range from 10 to 100 times stronger than steel, per unit weight. Recent studies also indicate that the nanotubes may be the best heat-conducting material in existence. These properties, combined with the ease of growing thin films or nanotubes by a variety of deposition techniques, make the carbon-based material one of the most desirable for cold field emission cathodes.

Paper-based three-dimensional electrochemical immunodevice based on multi-walled carbon nanotubes functionalized paper for sensitive point-of-care testing.

PubMed

Wang, Panpan; Ge, Lei; Yan, Mei; Song, Xianrang; Ge, Shenguang; Yu, Jinghua

2012-02-15

In this study, electrochemical immunoassay was introduced into the recently proposed microfluidic paper-based analytical device (μPADs). To improve the performance of electrochemical immunoassay on μPAD for point-of-care testing (POCT), a novel wax-patterned microfluidic paper-based three-dimensional electrochemical device (3D-μPED) was demonstrated based on the multi-walled carbon nanotubes (MWCNTs) modified μPAD. Using typical HRP-O-Phenylenediamine-H(2)O(2) electrochemical system, a sandwich immunoassay on this 3D-μPED for sensitive diagnosis of two tumor markers simultaneously in real clinical serum samples was developed with a linear range of 0.001-75.0 UmL(-1) for cancer antigen 125 and 0.05-50.0 ngmL(-1) for carcinoembryonic antigen. In addition, this 3D-μPED can be easily integrated and combined with the recently emerging paper electronics to further develop simple, sensitive, low-cost, disposable and portable μPAD for POCT, public health and environmental monitoring in remote regions, developing or developed countries. Copyright © 2011 Elsevier B.V. All rights reserved.

Reagentless D-sorbitol biosensor based on D-sorbitol dehydrogenase immobilized in a sol-gel carbon nanotubes-poly(methylene green) composite.

PubMed

Wang, Zhijie; Etienne, Mathieu; Urbanova, Veronika; Kohring, Gert-Wieland; Walcarius, Alain

2013-04-01

A reagentless D-sorbitol biosensor based on NAD-dependent D-sorbitol dehydrogenase (DSDH) immobilized in a sol-gel carbon nanotubes-poly(methylene green) composite has been developed. It was prepared by durably immobilizing the NAD(+) cofactor with DSDH in a sol-gel thin film on the surface of carbon nanotubes functionalized with poly(methylene green). This device enables selective determination of D-sorbitol at 0.2 V with a sensitivity of 8.7 μA mmol(-1) L cm(-2) and a detection limit of 0.11 mmol L(-1). Moreover, this biosensor has excellent operational stability upon continuous use in hydrodynamic conditions.

A fast and low-power microelectromechanical system-based non-volatile memory device

PubMed Central

Lee, Sang Wook; Park, Seung Joo; Campbell, Eleanor E. B.; Park, Yung Woo

2011-01-01

Several new generation memory devices have been developed to overcome the low performance of conventional silicon-based flash memory. In this study, we demonstrate a novel non-volatile memory design based on the electromechanical motion of a cantilever to provide fast charging and discharging of a floating-gate electrode. The operation is demonstrated by using an electromechanical metal cantilever to charge a floating gate that controls the charge transport through a carbon nanotube field-effect transistor. The set and reset currents are unchanged after more than 11 h constant operation. Over 500 repeated programming and erasing cycles were demonstrated under atmospheric conditions at room temperature without degradation. Multinary bit programming can be achieved by varying the voltage on the cantilever. The operation speed of the device is faster than a conventional flash memory and the power consumption is lower than other memory devices. PMID:21364559

Self-grafting carbon nanotubes on polymers for stretchable electronics

NASA Astrophysics Data System (ADS)

Morales, Piero; Moyanova, Slavianka; Pavone, Luigi; Fazi, Laura; Mirabile Gattia, Daniele; Rapone, Bruno; Gaglione, Anderson; Senesi, Roberto

2018-06-01

Elementary bidimensional circuitry made of single-wall carbon-nanotube-based conductors, self-grafted on different polymer films, is accomplished in an attempt to develop a simple technology for flexible and stretchable electronic devices. Unlike in other studies of polymer-carbon nanotube composites, no chemical functionalization of single-wall carbon nanotubes is necessary for stable grafting onto several polymeric surfaces, suggesting viable and cheap fabrication technologies for stretchable microdevices. Electrical characterization of both unstretched and strongly stretched conductors is provided, while an insight on the mechanisms of strong adhesion to the polymer is obtained by scanning electron microscopy of the surface composite. As a first example of technological application, the electrical functionality of a carbon-nanotube-based 6-sensor (electrode) grid was demonstrated by recording of subdural electrocorticograms in freely moving rats over approximately three months. The results are very promising and may serve as a basis for future work targeting clinical applications.

High-performance supercapacitors based on vertically aligned carbon nanotubes and nonaqueous electrolytes

NASA Astrophysics Data System (ADS)

Kim, Byungwoo; Chung, Haegeun; Kim, Woong

2012-04-01

We demonstrate the high performance of supercapacitors fabricated with vertically aligned carbon nanotubes and nonaqueous electrolytes such as ionic liquids and conventional organic electrolytes. Specific capacitance, maximum power and energy density of the supercapacitor measured in ionic liquid were ˜75 F g-1, ˜987 kW kg-1 and ˜27 W h kg-1, respectively. The high power performance was consistently indicated by a fast relaxation time constant of 0.2 s. In addition, electrochemical oxidation of the carbon nanotubes improved the specific capacitance (˜158 F g-1) and energy density (˜53 W h kg-1). Both high power and energy density could be attributed to the fast ion transport realized by the alignment of carbon nanotubes and the wide operational voltage defined by the ionic liquid. The demonstrated carbon-nanotube- and nonaqueous-electrolyte-based supercapacitors show great potential for the development of high-performance energy storage devices.

High-performance supercapacitors based on vertically aligned carbon nanotubes and nonaqueous electrolytes.

PubMed

Kim, Byungwoo; Chung, Haegeun; Kim, Woong

2012-04-20

We demonstrate the high performance of supercapacitors fabricated with vertically aligned carbon nanotubes and nonaqueous electrolytes such as ionic liquids and conventional organic electrolytes. Specific capacitance, maximum power and energy density of the supercapacitor measured in ionic liquid were ~75 F g(-1), ~987 kW kg(-1) and ~27 W h kg(-1), respectively. The high power performance was consistently indicated by a fast relaxation time constant of 0.2 s. In addition, electrochemical oxidation of the carbon nanotubes improved the specific capacitance (~158 F g(-1)) and energy density (~53 W h kg(-1)). Both high power and energy density could be attributed to the fast ion transport realized by the alignment of carbon nanotubes and the wide operational voltage defined by the ionic liquid. The demonstrated carbon-nanotube- and nonaqueous-electrolyte-based supercapacitors show great potential for the development of high-performance energy storage devices. © 2012 IOP Publishing Ltd

Computational Nanotechnology of Materials, Devices, and Machines: Carbon Nanotubes

NASA Technical Reports Server (NTRS)

Srivastava, Deepak; Kwak, Dolhan (Technical Monitor)

2000-01-01

The mechanics and chemistry of carbon nanotubes have relevance for their numerous electronic applications. Mechanical deformations such as bending and twisting affect the nanotube's conductive properties, and at the same time they possess high strength and elasticity. Two principal techniques were utilized including the analysis of large scale classical molecular dynamics on a shared memory architecture machine and a quantum molecular dynamics methodology. In carbon based electronics, nanotubes are used as molecular wires with topological defects which are mediated through various means. Nanotubes can be connected to form junctions.

Flexible microfluidic devices with three-dimensional interconnected microporous walls for gas and liquid applications.

PubMed

Yuen, Po Ki; DeRosa, Michael E

2011-10-07

This article presents a simple, low-cost method of fabrication and the applications of flexible polystyrene microfluidic devices with three-dimensional (3D) interconnected microporous walls based on treatment using a solvent/non-solvent mixture at room temperature. The complete fabrication process from device design concept to working device can be completed in less than an hour in a regular laboratory setting, without the need for expensive equipment. Microfluidic devices were used to demonstrate gas generation and absorption reactions by acidifying water with carbon dioxide (CO(2)) gas. By selectively treating the microporous structures with oxygen plasma, acidification of water by acetic acid (distilled white vinegar) perfusion was also demonstrated with the same device design.

Microchip-based electrochemical detection using a 3-D printed wall-jet electrode device.

PubMed

Munshi, Akash S; Martin, R Scott

2016-02-07

Three dimensional (3-D) printing technology has evolved dramatically in the last few years, offering the capability of printing objects with a variety of materials. Printing microfluidic devices using this technology offers various advantages such as ease and uniformity of fabrication, file sharing between laboratories, and increased device-to-device reproducibility. One unique aspect of this technology, when used with electrochemical detection, is the ability to produce a microfluidic device as one unit while also allowing the reuse of the device and electrode for multiple analyses. Here we present an alternate electrode configuration for microfluidic devices, a wall-jet electrode (WJE) approach, created by 3-D printing. Using microchip-based flow injection analysis, we compared the WJE design with the conventionally used thin-layer electrode (TLE) design. It was found that the optimized WJE system enhances analytical performance (as compared to the TLE design), with improvements in sensitivity and the limit of detection. Experiments were conducted using two working electrodes - 500 μm platinum and 1 mm glassy carbon. Using the 500 μm platinum electrode the calibration sensitivity was 16 times higher for the WJE device (as compared to the TLE design). In addition, use of the 1 mm glassy carbon electrode led to limit of detection of 500 nM for catechol, as compared to 6 μM for the TLE device. Finally, to demonstrate the versatility and applicability of the 3-D printed WJE approach, the device was used as an inexpensive electrochemical detector for HPLC. The number of theoretical plates was comparable to the use of commercially available UV and MS detectors, with the WJE device being inexpensive to utilize. These results show that 3-D-printing can be a powerful tool to fabricate reusable and integrated microfluidic detectors in configurations that are not easily achieved with more traditional lithographic methods.

Active Flow Control with Thermoacoustic Actuators

DTIC Science & Technology

2014-01-31

AC power has been shown to produce large-amplitude acoustic waves [6]. The input AC current sinusoidally heats this device due to joule heating and...conventional metals, the heat capacity value for carbon-based material (carbon nanotubes/graphene) in consideration here is at least 2 orders of...magnitude smaller. Since the output acoustic power delivered to the surrounding flow field is related inversely to the material heat capacity C (i.e., Poutput

21 CFR 866.5200 - Carbonic anhydrase B and C immunological test system.

Code of Federal Regulations, 2011 CFR

2011-04-01

... HUMAN SERVICES (CONTINUED) MEDICAL DEVICES IMMUNOLOGY AND MICROBIOLOGY DEVICES Immunological Test... immunochemical techniques specific carbonic anhydrase protein molecules in serum and other body fluids. Measurements of carbonic anhydrase B and C aid in the diagnosis of abnormal hemoglobin metabolism. (b...

21 CFR 866.5200 - Carbonic anhydrase B and C immunological test system.

Code of Federal Regulations, 2013 CFR

2013-04-01

... HUMAN SERVICES (CONTINUED) MEDICAL DEVICES IMMUNOLOGY AND MICROBIOLOGY DEVICES Immunological Test... immunochemical techniques specific carbonic anhydrase protein molecules in serum and other body fluids. Measurements of carbonic anhydrase B and C aid in the diagnosis of abnormal hemoglobin metabolism. (b...

21 CFR 866.5200 - Carbonic anhydrase B and C immunological test system.

Code of Federal Regulations, 2014 CFR

2014-04-01

... HUMAN SERVICES (CONTINUED) MEDICAL DEVICES IMMUNOLOGY AND MICROBIOLOGY DEVICES Immunological Test... immunochemical techniques specific carbonic anhydrase protein molecules in serum and other body fluids. Measurements of carbonic anhydrase B and C aid in the diagnosis of abnormal hemoglobin metabolism. (b...

21 CFR 866.5200 - Carbonic anhydrase B and C immunological test system.

Code of Federal Regulations, 2012 CFR

2012-04-01

... HUMAN SERVICES (CONTINUED) MEDICAL DEVICES IMMUNOLOGY AND MICROBIOLOGY DEVICES Immunological Test... immunochemical techniques specific carbonic anhydrase protein molecules in serum and other body fluids. Measurements of carbonic anhydrase B and C aid in the diagnosis of abnormal hemoglobin metabolism. (b...

21 CFR 878.3500 - Polytetrafluoroethylene with carbon fibers composite implant material.

Code of Federal Regulations, 2010 CFR

2010-04-01

... composite implant material. 878.3500 Section 878.3500 Food and Drugs FOOD AND DRUG ADMINISTRATION... Prosthetic Devices § 878.3500 Polytetrafluoroethylene with carbon fibers composite implant material. (a) Identification. A polytetrafluoroethylene with carbon fibers composite implant material is a porous device...

Carbon Nanotube Based Devices for Intracellular Analysis

NASA Astrophysics Data System (ADS)

Singhal, Riju Mohan

Scientific investigations on individual cells have gained increasing attention in recent years as efforts are being made to understand cellular functioning in complex processes, such as cell division during embryonic development, and owing to realization of heterogeneity amongst a population of a single cell type (for instance, certain individual cancer cells being immune to chemotherapy). Therefore devices enabling electrochemical detection, spectroscopy, optical observations, and separation techniques, along with cell piercing and fluid transfer capabilities at the intra-cellular level, are required. Glass pipettes have conventionally been used for single cell interrogation, however their poor mechanical properties and an intrusive conical geometry have led to limited precision and frequent cell damage or death, justifying research efforts to develop novel, non-intrusive cell probes. Carbon nanotubes (CNTs) are known for their superior physical properties and tunable chemical structure. They possess a high aspect ratio and offer minimally invasive thin carbon walls and tubular geometry. Moreover, possibility of chemical functionalization of CNTs enables multi-functional probes. In this dissertation, novel nanofluidic instruments that have nanostructured carbon tips will be presented along with techniques that utilize the exceptional physical properties of carbon nanotubes, to take miniature biomedical instrumentation to the next level. New methods for fabricating the probes were rigorously developed and their operation was extensively studied. The devices were mechanically robust and were used to inject liquids to a single cell, detect electrochemical signals and enable surface enhanced Raman spectroscopy (SERS) while inducing minimal harm to the cell. Particular attention was focused on the CVD process-which was used to deposit carbon, fluid flow through the nanotubes, and separation of chemical species (atto-liter chromatography) at the nanometer scale that would potentially lead to the highly sought after "selective component extraction" and analysis from a single cell. These multi-functional devices therefore provide a picture of the physiological state of a living cell and function as endoscopes for single cell analysis.

Practical application to composite materials of a portable digital ultrasound device controlled by a microprocessor

NASA Astrophysics Data System (ADS)

Castel, J. G.; Husarek, V.

1987-06-01

The usefulness of a portable microprocessor-controlled ultrasound device for the periodic assessment of aircraft parts made of composite materials is shown. The performance of the device is demonstrated with the examples of a metallic honeycomb with a carbon-fiber skin, a phenolic honeycomb with a carbon skin, and a phenolic honeycomb with a Kevlar skin. Also considered are assessments of homogeneous carbon-fiber parts, including the study of artificial defects consisting of 1-2 mm diameter holes, and the assessment of the behavior of a carbon-titanium interface with separated zones. Advantages of the device include ease of adjustment, automated evaluation of the depth of defects, and the nearly-absolute reproducibility of adjustments.

Design, Fabrication, and Characterization of Carbon Nanotube Field Emission Devices for Advanced Applications

NASA Astrophysics Data System (ADS)

Radauscher, Erich Justin

Carbon nanotubes (CNTs) have recently emerged as promising candidates for electron field emission (FE) cathodes in integrated FE devices. These nanostructured carbon materials possess exceptional properties and their synthesis can be thoroughly controlled. Their integration into advanced electronic devices, including not only FE cathodes, but sensors, energy storage devices, and circuit components, has seen rapid growth in recent years. The results of the studies presented here demonstrate that the CNT field emitter is an excellent candidate for next generation vacuum microelectronics and related electron emission devices in several advanced applications. The work presented in this study addresses determining factors that currently confine the performance and application of CNT-FE devices. Characterization studies and improvements to the FE properties of CNTs, along with Micro-Electro-Mechanical Systems (MEMS) design and fabrication, were utilized in achieving these goals. Important performance limiting parameters, including emitter lifetime and failure from poor substrate adhesion, are examined. The compatibility and integration of CNT emitters with the governing MEMS substrate (i.e., polycrystalline silicon), and its impact on these performance limiting parameters, are reported. CNT growth mechanisms and kinetics were investigated and compared to silicon (100) to improve the design of CNT emitter integrated MEMS based electronic devices, specifically in vacuum microelectronic device (VMD) applications. Improved growth allowed for design and development of novel cold-cathode FE devices utilizing CNT field emitters. A chemical ionization (CI) source based on a CNT-FE electron source was developed and evaluated in a commercial desktop mass spectrometer for explosives trace detection. This work demonstrated the first reported use of a CNT-based ion source capable of collecting CI mass spectra. The CNT-FE source demonstrated low power requirements, pulsing capabilities, and average lifetimes of over 320 hours when operated in constant emission mode under elevated pressures, without sacrificing performance. Additionally, a novel packaged ion source for miniature mass spectrometer applications using CNT emitters, a MEMS based Nier-type geometry, and a Low Temperature Cofired Ceramic (LTCC) 3D scaffold with integrated ion optics were developed and characterized. While previous research has shown other devices capable of collecting ion currents on chip, this LTCC packaged MEMS micro-ion source demonstrated improvements in energy and angular dispersion as well as the ability to direct the ions out of the packaged source and towards a mass analyzer. Simulations and experimental design, fabrication, and characterization were used to make these improvements. Finally, novel CNT-FE devices were developed to investigate their potential to perform as active circuit elements in VMD circuits. Difficulty integrating devices at micron-scales has hindered the use of vacuum electronic devices in integrated circuits, despite the unique advantages they offer in select applications. Using a combination of particle trajectory simulation and experimental characterization, device performance in an integrated platform was investigated. Solutions to the difficulties in operating multiple devices in close proximity and enhancing electron transmission (i.e., reducing grid loss) are explored in detail. A systematic and iterative process was used to develop isolation structures that reduced crosstalk between neighboring devices from 15% on average, to nearly zero. Innovative geometries and a new operational mode reduced grid loss by nearly threefold, thereby improving transmission of the emitted cathode current to the anode from 25% in initial designs to 70% on average. These performance enhancements are important enablers for larger scale integration and for the realization of complex vacuum microelectronic circuits.

Recent Advances in the Fabrication and Application of Screen-Printed Electrochemical (Bio)Sensors Based on Carbon Materials for Biomedical, Agri-Food and Environmental Analyses

PubMed Central

Hughes, Gareth; Westmacott, Kelly; Honeychurch, Kevin C.; Crew, Adrian; Pemberton, Roy M.; Hart, John P.

2016-01-01

This review describes recent advances in the fabrication of electrochemical (bio)sensors based on screen-printing technology involving carbon materials and their application in biomedical, agri-food and environmental analyses. It will focus on the various strategies employed in the fabrication of screen-printed (bio)sensors, together with their performance characteristics; the application of these devices for the measurement of selected naturally occurring biomolecules, environmental pollutants and toxins will be discussed. PMID:27690118

Enhanced-wetting, boron-based liquid-metal ion source and method

DOEpatents

Bozack, Michael J.; Swanson, Lynwood W.; Bell, Anthony E.; Clark Jr., William M.; Utlaut, Mark W.; Storms, Edmund K.

1999-01-01

A binary, boron-based alloy as a source for field-emission-type, ion-beam generating devices, wherein boron predominates in the alloy, preferably with a presence of about 60 atomic percent. The other constituent in the alloy is selected from the group of elements consisting of nickel, palladium and platinum. Predominance of boron in these alloys, during operation, promotes combining of boron with trace impurities of carbon in the alloys to form B.sub.4 C and thus to promote wetting of an associated carbon support substrate.

Enhanced-wetting, boron-based liquid-metal ion source and method

DOEpatents

Bozack, M.J.; Swanson, L.W.; Bell, A.E.; Clark, W.M. Jr.; Utlaut, M.W.; Storms, E.K.

1999-02-16

A binary, boron-based alloy as a source for field-emission-type, ion-beam generating devices, wherein boron predominates in the alloy, preferably with a presence of about 60 atomic percent is disclosed. The other constituent in the alloy is selected from the group of elements consisting of nickel, palladium and platinum. Predominance of boron in these alloys, during operation, promotes combining of boron with trace impurities of carbon in the alloys to form B{sub 4}C and thus to promote wetting of an associated carbon support substrate. 1 fig.

Carbon nanotubes and graphene towards soft electronics

NASA Astrophysics Data System (ADS)

Chae, Sang Hoon; Lee, Young Hee

2014-04-01

Although silicon technology has been the main driving force for miniaturizing device dimensions to improve cost and performance, the current application of Si to soft electronics (flexible and stretchable electronics) is limited due to material rigidity. As a result, various prospective materials have been proposed to overcome the rigidity of conventional Si technology. In particular, nano-carbon materials such as carbon nanotubes (CNTs) and graphene are promising due to outstanding elastic properties as well as an excellent combination of electronic, optoelectronic, and thermal properties compared to conventional rigid silicon. The uniqueness of these nano-carbon materials has opened new possibilities for soft electronics, which is another technological trend in the market. This review covers the recent progress of soft electronics research based on CNTs and graphene. We discuss the strategies for soft electronics with nano-carbon materials and their preparation methods (growth and transfer techniques) to devices as well as the electrical characteristics of transparent conducting films (transparency and sheet resistance) and device performances in field effect transistor (FET) (structure, carrier type, on/off ratio, and mobility). In addition to discussing state of the art performance metrics, we also attempt to clarify trade-off issues and methods to control the trade-off on/off versus mobility). We further demonstrate accomplishments of the CNT network in flexible integrated circuits on plastic substrates that have attractive characteristics. A future research direction is also proposed to overcome current technological obstacles necessary to realize commercially feasible soft electronics.

Carbon nanotubes and graphene towards soft electronics.

PubMed

Chae, Sang Hoon; Lee, Young Hee

2014-01-01

Although silicon technology has been the main driving force for miniaturizing device dimensions to improve cost and performance, the current application of Si to soft electronics (flexible and stretchable electronics) is limited due to material rigidity. As a result, various prospective materials have been proposed to overcome the rigidity of conventional Si technology. In particular, nano-carbon materials such as carbon nanotubes (CNTs) and graphene are promising due to outstanding elastic properties as well as an excellent combination of electronic, optoelectronic, and thermal properties compared to conventional rigid silicon. The uniqueness of these nano-carbon materials has opened new possibilities for soft electronics, which is another technological trend in the market. This review covers the recent progress of soft electronics research based on CNTs and graphene. We discuss the strategies for soft electronics with nano-carbon materials and their preparation methods (growth and transfer techniques) to devices as well as the electrical characteristics of transparent conducting films (transparency and sheet resistance) and device performances in field effect transistor (FET) (structure, carrier type, on/off ratio, and mobility). In addition to discussing state of the art performance metrics, we also attempt to clarify trade-off issues and methods to control the trade-off on/off versus mobility). We further demonstrate accomplishments of the CNT network in flexible integrated circuits on plastic substrates that have attractive characteristics. A future research direction is also proposed to overcome current technological obstacles necessary to realize commercially feasible soft electronics.

3D Printed Microfluidic Devices with Integrated Versatile and Reusable Electrodes

PubMed Central

Erkal, Jayda L.; Selimovic, Asmira; Gross, Bethany C.; Lockwood, Sarah Y.; Walton, Eric L.; McNamara, Stephen; Martin, R. Scott; Spence, Dana M.

2014-01-01

We report two 3D printed devices that can be used for electrochemical detection. In both cases, the electrode is housed in commercially available, polymer-based fittings so that the various electrode materials (platinum, platinum black, carbon, gold, silver) can be easily added to a threaded receiving port printed on the device; this enables a module-like approach to the experimental design, where the electrodes are removable and can be easily repolished for reuse after exposure to biological samples. The first printed device represents a microfluidic platform with a 500 × 500 μm channel and a threaded receiving port to allow integration of either polyetheretherketone (PEEK) nut-encased glassy carbon or platinum black (Pt-black) electrodes for dopamine and nitric oxide (NO) detection, respectively. The embedded 1 mm glassy carbon electrode had a limit of detection (LOD) of 500 nM for dopamine and a linear response (R2= 0.99) for concentrations between 25-500 μM. When the glassy carbon electrode was coated with 0.05% Nafion, significant exclusion of nitrite was observed when compared to signal obtained from equimolar injections of dopamine. When using flow injection analysis with a Pt/Pt-black electrode and standards derived from NO gas, a linear correlation (R2 = 0.99) over a wide range of concentrations (7.6 - 190 μM) was obtained, with the LOD for NO being 1 μM. The second application showcases a 3D printed fluidic device that allows collection of the biologically relevant analyte adenosine triphosphate (ATP) while simultaneously measuring the release stimulus (reduced oxygen concentration). The hypoxic sample (4.76 ± 0.53 ppm oxygen) released 2.37 ± 0.37 times more ATP than the normoxic sample (8.22 ± 0.60 ppm oxygen). Importantly, the results reported here verify the reproducible and transferable nature of using 3D printing as a fabrication technique, as devices and electrodes were moved between labs multiple times during completion of the study. PMID:24763966

Titanium dioxide@polypyrrole core-shell nanowires for all solid-state flexible supercapacitors

NASA Astrophysics Data System (ADS)

Yu, Minghao; Zeng, Yinxiang; Zhang, Chong; Lu, Xihong; Zeng, Chenghui; Yao, Chenzhong; Yang, Yangyi; Tong, Yexiang

2013-10-01

Herein, we developed a facile two-step process to synthesize TiO2@PPy core-shell nanowires (NWs) on carbon cloth and reported their improved electrochemical performance for flexible supercapacitors (SCs). The fabricated solid-state SC device based on TiO2@PPy core-shell NWs not only has excellent flexibility, but also exhibits remarkable electrochemical performance.Herein, we developed a facile two-step process to synthesize TiO2@PPy core-shell nanowires (NWs) on carbon cloth and reported their improved electrochemical performance for flexible supercapacitors (SCs). The fabricated solid-state SC device based on TiO2@PPy core-shell NWs not only has excellent flexibility, but also exhibits remarkable electrochemical performance. Electronic supplementary information (ESI) available: Experimental details, XRD pattern, FT-IR absorption spectrum and CV curves of TiO2@PPy NWs, and SEM images of the PPy. See DOI: 10.1039/c3nr03578f

Highly efficient growth of vertically aligned carbon nanotubes on Fe-Ni based metal alloy foils for supercapacitors

NASA Astrophysics Data System (ADS)

Amalina Raja Seman, Raja Noor; Asyadi Azam, Mohd; Ambri Mohamed, Mohd

2016-12-01

Supercapacitors are highly promising energy devices with superior charge storage performance and a long lifecycle. Construction of the supercapacitor cell, especially electrode fabrication, is critical to ensure good performance in applications. This work demonstrates direct growth of vertically aligned carbon nanotubes (CNTs) on Fe-Ni based metal alloy foils, namely SUS 310S, Inconel 600 and YEF 50, and their use in symmetric vertically aligned CNT supercapacitor electrodes. Alumina and cobalt thin film catalysts were deposited onto the foils, and then CNT growth was performed using alcohol catalytic chemical vapour deposition. By this method, vertically aligned CNTs were successfully grown and used directly as a binder-free supercapacitor electrode to deliver excellent electrochemical performance. The device showed relatively good specific capacitance, a superior rate capability and excellent cycle stability, maintaining about 96% capacitance up to 1000 cycles.

Investigation and demonstration of dry carbon-based sorbent injection for mercury control. Quarterly technical report, July 1, 1996--September 31, 1996

DOE Office of Scientific and Technical Information (OSTI.GOV)

Hunt, T.; Sjostrom, S.; Smith, J.

1996-11-06

The overall objective of this two phase program is to investigate the use of dry carbon-based sorbents for mercury control. This information is important to the utility industry in anticipation of pending regulations. During Phase I, a bench-scale field test device that can be configured as an electrostatic precipitator, a pulse-jet baghouse, or a reverse-gas baghouse has been designed, built and integrated with an existing pilot-scale facility at PSCo`s Comanche Station. Up to three candidate sorbents will be injected into the flue gas stream upstream of the test device to and mercury concentration measurements will be made to determine themore » mercury removal efficiency for each sorbent. During the Phase II effort, component integration for the most promising dry sorbent technology shall be tested at the 5000 acfm pilot-scale.« less

Designing Carbon Based Supercapacitors with High Energy Density: A Summary of Recent Progress.

PubMed

Han, Yi; Lai, Zhengzhe; Wang, Zifan; Yu, Minghao; Tong, Yexiang; Lu, Xihong

2018-05-23

Carbon based supercapacitors (CSCs), with high output power and long lifespan, are considered as promising power sources for modern electronic devices. The rush to find new approaches for optimizing their electrochemical behaviors is still vibrant, and particularly, widespread enthusiasm was focused on improving the energy density of CSCs through improving the specific capacitance and expanding the operating voltage. In this regard, this article provides a brief review about recent progress and new understanding about the assembly of CSCs with high energy density. Novel applied strategies were highlighted and discussed from the aspects of electrolyte, electrodes, and device modulation. Dynamic and mechanism factors associated with the energy storage process of CSCs are particularly emphasized. Finally, the opportunities and challenges are elaborated in the hope of guiding the promising direction for the design of high-energy CSCs. © 2018 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

Activated-Carbon Sorbent With Integral Heat-Transfer Device

NASA Technical Reports Server (NTRS)

Jones, Jack A.; Yavrouian, Andre

1996-01-01

Prototype adsorption device used, for example, in adsorption heat pump, to store natural gas to power automobile, or to separate components of fluid mixtures. Device includes activated carbon held together by binder and molded into finned heat-transfer device providing rapid heating or cooling to enable rapid adsorption or desorption of fluids. Concepts of design and fabrication of device equally valid for such other highly thermally conductive devices as copper-finned tubes, and for such other high-surface-area sorbents as zeolites or silicates.

Silicon on ferroelectic insulator field effect transistor (SOF-FET) a new device for the next generation ultra low power circuits

NASA Astrophysics Data System (ADS)

Es-Sakhi, Azzedin D.

Field effect transistors (FETs) are the foundation for all electronic circuits and processors. These devices have progressed massively to touch its final steps in sub-nanometer level. Left and right proposals are coming to rescue this progress. Emerging nano-electronic devices (resonant tunneling devices, single-atom transistors, spin devices, Heterojunction Transistors rapid flux quantum devices, carbon nanotubes, and nanowire devices) took a vast share of current scientific research. Non-Si electronic materials like III-V heterostructure, ferroelectric, carbon nanotubes (CNTs), and other nanowire based designs are in developing stage to become the core technology of non-classical CMOS structures. FinFET present the current feasible commercial nanotechnology. The scalability and low power dissipation of this device allowed for an extension of silicon based devices. High short channel effect (SCE) immunity presents its major advantage. Multi-gate structure comes to light to improve the gate electrostatic over the channel. The new structure shows a higher performance that made it the first candidate to substitute the conventional MOSFET. The device also shows a future scalability to continue Moor's Law. Furthermore, the device is compatible with silicon fabrication process. Moreover, the ultra-low-power (ULP) design required a subthreshold slope lower than the thermionic-emission limit of 60mV/ decade (KT/q). This value was unbreakable by the new structure (SOI-FinFET). On the other hand most of the previews proposals show the ability to go beyond this limit. However, those pre-mentioned schemes have publicized a very complicated physics, design difficulties, and process non-compatibility. The objective of this research is to discuss various emerging nano-devices proposed for ultra-low-power designs and their possibilities to replace the silicon devices as the core technology in the future integrated circuit. This thesis proposes a novel design that exploits the concept of negative capacitance. The new field effect transistor (FET) based on ferroelectric insulator named Silicon-On-Ferroelectric Insulator Field Effect Transistor (SOF-FET). This proposal is a promising methodology for future ultra-low-power applications, because it demonstrates the ability to replace the silicon-bulk based MOSFET, and offers subthreshold swing significantly lower than 60mV/decade and reduced threshold voltage to form a conducting channel. The SOF-FET can also solve the issue of junction leakage (due to the presence of unipolar junction between the top plate of the negative capacitance and the diffused areas that form the transistor source and drain). In this device the charge hungry ferroelectric film already limits the leakage.

Carbon Nanotube-Based Ion Selective Sensors for Wearable Applications.

PubMed

Roy, Soumyendu; David-Pur, Moshe; Hanein, Yael

2017-10-11

Wearable electronics offer new opportunities in a wide range of applications, especially sweat analysis using skin sensors. A fundamental challenge in these applications is the formation of sensitive and stable electrodes. In this article we report the development of a wearable sensor based on carbon nanotube (CNT) electrode arrays for sweat sensing. Solid-state ion selective electrodes (ISEs), sensitive to Na + ions, were prepared by drop coating plasticized poly(vinyl chloride) (PVC) doped with ionophore and ion exchanger on CNT electrodes. The ion selective membrane (ISM) filled the intertubular spaces of the highly porous CNT film and formed an attachment that was stronger than that achieved with flat Au, Pt, or carbon electrodes. Concentration of the ISM solution used influenced the attachment to the CNT film, the ISM surface morphology, and the overall performance of the sensor. Sensitivity of 56 ± 3 mV/decade to Na + ions was achieved. Optimized solid-state reference electrodes (REs), suitable for wearable applications, were prepared by coating CNT electrodes with colloidal dispersion of Ag/AgCl, agarose hydrogel with 0.5 M NaCl, and a passivation layer of PVC doped with NaCl. The CNT-based REs had low sensitivity (-1.7 ± 1.2 mV/decade) toward the NaCl solution and high repeatability and were superior to bare Ag/AgCl, metals, carbon, and CNT films, reported previously as REs. CNT-based ISEs were calibrated against CNT-based REs, and the short-term stability of the system was tested. We demonstrate that CNT-based devices implemented on a flexible support are a very attractive platform for future wearable technology devices.

Improved thermoelectric power output from multilayered polyethylenimine doped carbon nanotube based organic composites

NASA Astrophysics Data System (ADS)

Hewitt, Corey A.; Montgomery, David S.; Barbalace, Ryan L.; Carlson, Rowland D.; Carroll, David L.

2014-05-01

By appropriately selecting the carbon nanotube type and n-type dopant for the conduction layers in a multilayered carbon nanotube composite, the total device thermoelectric power output can be increased significantly. The particular materials chosen in this study were raw single walled carbon nanotubes for the p-type layers and polyethylenimine doped single walled carbon nanotubes for the n-type layers. The combination of these two conduction layers leads to a single thermocouple Seebeck coefficient of 96 ± 4 μVK-1, which is 6.3 times higher than that previously reported. This improved Seebeck coefficient leads to a total power output of 14.7 nW per thermocouple at the maximum temperature difference of 50 K, which is 44 times the power output per thermocouple for the previously reported results. Ultimately, these thermoelectric power output improvements help to increase the potential use of these lightweight, flexible, and durable organic multilayered carbon nanotube based thermoelectric modules in low powered electronics applications, where waste heat is available.

Low-dimensional carbon and MXene-based electrochemical capacitor electrodes.

PubMed

Yoon, Yeoheung; Lee, Keunsik; Lee, Hyoyoung

2016-04-29

Due to their unique structure and outstanding intrinsic physical properties such as extraordinarily high electrical conductivity, large surface area, and various chemical functionalities, low-dimension-based materials exhibit great potential for application in electrochemical capacitors (ECs). The electrical properties of electrochemical capacitors are determined by the electrode materials. Because energy charge storage is a surface process, the surface properties of the electrode materials greatly influence the electrochemical performance of the cell. Recently, graphene, a single layer of sp(2)-bonded carbon atoms arrayed into two-dimensional carbon nanomaterial, has attracted wide interest as an electrode material for electrochemical capacitor applications due to its unique properties, including a high electrical conductivity and large surface area. Several low-dimensional materials with large surface areas and high conductivity such as onion-like carbons (OLCs), carbide-derived carbons (CDCs), carbon nanotubes (CNTs), graphene, metal hydroxide, transition metal dichalcogenides (TMDs), and most recently MXene, have been developed for electrochemical capacitors. Therefore, it is useful to understand the current issues of low-dimensional materials and their device applications.

Composite electronic materials based on poly(3,4-propylenedioxythiophene) and highly charged poly(aryleneethynylene)-wrapped carbon nanotubes for supercapacitors.

PubMed

Rosario-Canales, Mariem R; Deria, Pravas; Therien, Michael J; Santiago-Avilés, Jorge J

2012-01-01

Supercapacitor charge storage media were fabricated using the semiconducting polymer poly(3,4-propylenedioxythiophene) (PProDOT) and single-walled carbon nanotubes (SWNTs) that were helically wrapped with ionic, conjugated poly[2,6-{1,5-bis(3-propoxysulfonicacidsodiumsalt)}naphthylene]ethynylene (PNES). These PNES-wrapped SWNTs (PNES-SWNTs) enable efficient dispersion of individualized nanotubes in a wide range of organic solvents. PNES-SWNT film-modified Pt electrodes were prepared by drop casting PNES-SWNT suspensions in MeOH; high stability, first-generation PProDOT/PNES/SWNT composites were realized via electropolymerization of the ProDOT parent monomer (3,4-propylenedioxythiophene) in a 1-ethyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide/propylene carbonate solution at the PNES-SWNT-modified electrode. The electrochemical properties of PProDOT and PProDOT/PNES/SWNT single electrodes and devices were examined using cyclic voltammetric methods. The hybrid composites were found to enhance key supercapacitor figures of merit (charge capacity and capacitance) by approximately a factor of 2 relative to those determined for benchmark Type I devices that exploited a classic PProDOT-based electrode material. The charge/discharge stability of the supercapacitors was probed by repeated rounds of cyclic voltammetric evaluation at a minimum depth of discharge of 73%; these experiments demonstrated that the hybrid PProDOT/PNES/SWNT composites retained ~90% of their initial charge capacity after 21,000 charge/discharge cycles, contrasting analogous data obtained for PProDOT-based devices, which showed only 84% retention of their initial charge capacity. © 2011 American Chemical Society

Process for attaching molecular wires and devices to carbon nanotubes and compositions thereof

NASA Technical Reports Server (NTRS)

Yang, Jiping (Inventor); Tour, James M. (Inventor); Bahr, Jeffrey L. (Inventor)

2008-01-01

The present invention is directed towards processes for covalently attaching molecular wires and molecular electronic devices to carbon nanotubes and compositions thereof. Such processes utilize diazonium chemistry to bring about this marriage of wire-like nanotubes with molecular wires and molecular electronic devices.

[Simplified identification and filter device of carbon dioxide].

PubMed

Mei, Xue-qin; Zhang, Yi-ping

2009-11-01

This paper presents the design and implementation ways of a simplified device to identify and filter carbon dioxide. The gas went through the test interface which had wet litmus paper before entering the abdominal cavity. Carbon dioxide dissolving in water turned acidic, making litmus paper change color to identify carbon dioxide, in order to avoid malpractice by connecting the wrong gas when making Endoscopic surgery.

Conductive MOF electrodes for stable supercapacitors with high areal capacitance.

PubMed

Sheberla, Dennis; Bachman, John C; Elias, Joseph S; Sun, Cheng-Jun; Shao-Horn, Yang; Dincă, Mircea

2017-02-01

Owing to their high power density and superior cyclability relative to batteries, electrochemical double layer capacitors (EDLCs) have emerged as an important electrical energy storage technology that will play a critical role in the large-scale deployment of intermittent renewable energy sources, smart power grids, and electrical vehicles. Because the capacitance and charge-discharge rates of EDLCs scale with surface area and electrical conductivity, respectively, porous carbons such as activated carbon, carbon nanotubes and crosslinked or holey graphenes are used exclusively as the active electrode materials in EDLCs. One class of materials whose surface area far exceeds that of activated carbons, potentially allowing them to challenge the dominance of carbon electrodes in EDLCs, is metal-organic frameworks (MOFs). The high porosity of MOFs, however, is conventionally coupled to very poor electrical conductivity, which has thus far prevented the use of these materials as active electrodes in EDLCs. Here, we show that Ni 3 (2,3,6,7,10,11-hexaiminotriphenylene) 2 (Ni 3 (HITP) 2 ), a MOF with high electrical conductivity, can serve as the sole electrode material in an EDLC. This is the first example of a supercapacitor made entirely from neat MOFs as active materials, without conductive additives or other binders. The MOF-based device shows an areal capacitance that exceeds those of most carbon-based materials and capacity retention greater than 90% over 10,000 cycles, in line with commercial devices. Given the established structural and compositional tunability of MOFs, these results herald the advent of a new generation of supercapacitors whose active electrode materials can be tuned rationally, at the molecular level.

Conductive MOF electrodes for stable supercapacitors with high areal capacitance

NASA Astrophysics Data System (ADS)

Sheberla, Dennis; Bachman, John C.; Elias, Joseph S.; Sun, Cheng-Jun; Shao-Horn, Yang; Dincă, Mircea

2017-02-01

Owing to their high power density and superior cyclability relative to batteries, electrochemical double layer capacitors (EDLCs) have emerged as an important electrical energy storage technology that will play a critical role in the large-scale deployment of intermittent renewable energy sources, smart power grids, and electrical vehicles. Because the capacitance and charge-discharge rates of EDLCs scale with surface area and electrical conductivity, respectively, porous carbons such as activated carbon, carbon nanotubes and crosslinked or holey graphenes are used exclusively as the active electrode materials in EDLCs. One class of materials whose surface area far exceeds that of activated carbons, potentially allowing them to challenge the dominance of carbon electrodes in EDLCs, is metal-organic frameworks (MOFs). The high porosity of MOFs, however, is conventionally coupled to very poor electrical conductivity, which has thus far prevented the use of these materials as active electrodes in EDLCs. Here, we show that Ni3(2,3,6,7,10,11-hexaiminotriphenylene)2 (Ni3(HITP)2), a MOF with high electrical conductivity, can serve as the sole electrode material in an EDLC. This is the first example of a supercapacitor made entirely from neat MOFs as active materials, without conductive additives or other binders. The MOF-based device shows an areal capacitance that exceeds those of most carbon-based materials and capacity retention greater than 90% over 10,000 cycles, in line with commercial devices. Given the established structural and compositional tunability of MOFs, these results herald the advent of a new generation of supercapacitors whose active electrode materials can be tuned rationally, at the molecular level.

Fabrication of Gate-Electrode Integrated Carbon-Nanotube Bundle Field Emitters

NASA Technical Reports Server (NTRS)

Toda, Risaku; Bronikowski, Michael; Luong, Edward; Manohara, Harish

2008-01-01

A continuing effort to develop carbon-nanotube-based field emitters (cold cathodes) as high-current-density electron sources has yielded an optimized device design and a fabrication scheme to implement the design. One major element of the device design is to use a planar array of bundles of carbon nanotubes as the field-emission tips and to optimize the critical dimensions of the array (principally, heights of bundles and distances between them) to obtain high area-averaged current density and high reliability over a long operational lifetime a concept that was discussed in more detail in Arrays of Bundles of Carbon Nanotubes as Field Emitters (NPO-40817), NASA Tech Briefs, Vol. 31, No. 2 (February 2007), page 58. Another major element of the design is to configure the gate electrodes (anodes used to extract, accelerate, and/or focus electrons) as a ring that overhangs a recess wherein the bundles of nanotubes are located, such that by virtue of the proximity between the ring and the bundles, a relatively low applied potential suffices to generate the large electric field needed for emission of electrons.

Synthesis and Applications of Large Area Graphene-Based Electrode Systems

NASA Astrophysics Data System (ADS)

Paul, Rajat Kanti

Graphene is a single sheet of carbon atoms with outstanding electrical and physical properties and being exploited for applications in electronics, sensors, fuel cells, photovoltaics and energy storage. However, practical designs of graphene-based electrode systems and related experimental implementations are required to realize their widespread applications in nano- to bioelectronics. In this dissertation, different graphene-based electrode systems having metallic and semiconducting properties are synthesized optimizing process conditions. Also realized is the potential of the fabricated electrode systems by applying them in practical applications such as sensor devices and fuel cells. The zero bandgap of semimetal graphene still limits its application as an effective field-effect transistor device or a chemiresistor sensor operating at room temperature. It has been shown theoretically and experimentally that graphene nanoribbons (GNRs) or nanomeshes (GNMs) can attain a bandgap that is large enough for a transistor device, and hence would show high sensitivity to various gaseous species or biomolecules. Large-area mono- and bilayer graphene films are synthesized by a simple chemical vapor deposition (CVD) technique depending on the carbon precursors such as methane, acetylene and ethanol, and the results are compared using optical microscopy (OM), Raman spectroscopy, high-resolution transmission electron microscopy (HRTEM) and x-ray photoelectron spectroscopy (XPS). A simple reactive ion etching (RIE) combined with well-established nanosphere lithography is performed on the synthesized CVD-grown monolayer graphene platform to fabricate large area GNMs with specific dimension and periodicity. The fabricated GNMs chemiresistor sensor devices show excellent sensitivity towards NO2 and NH 3, significantly higher than their film counterparts. The GNM sensor devices exhibit sensitivities of about 4.32%/ppm (parts-per-million) in NO 2 and 0.71%/ppm in NH3 with estimated limit of detections of 15 ppb (parts-per billion) and 160 ppb, significantly lower than Occupational Safety and Health Administration (OSHA) permissible exposure limits of 5 ppm (NO2) and 50 ppm (NH3), respectively. The demonstrated studies on the sensing properties of graphene nanomesh would essentially lead further improvement of it's sensitivity and selectivity as a potential sensor material. Furthermore, a three-dimensional (3D) carbon electrode in the form of vertically aligned carbon nanotubes (CNTs) on a graphene floor is applied as a supporting electrode for platinum (Pt) nanoflowers electrocatalysts in methanol oxidation as well as in nonenzymatic sensing of blood glucose. Experimental results demonstrate an enhanced efficiency of the 3D graphene-carbon nanotubes hybrid film, as catalyst support, for methanol oxidation with regard to electroactive surface area, forward anodic peak current density, onset oxidation potential, diffusion efficiency and the ratio of forward to backward anodic peak current density (If/Ib). Also, the developed nonenzymatic 3D carbon hybrid sensor responded linearly to the physiological glucose concentration ranging from 1 to 7 mM (R2 = 0.978) with a sensitivity of 11.06 muA mM-1cm-2.

KSC-2009-5108

NASA Image and Video Library

2009-09-12

EDWARDS AIR FORCE BASE, Calif. -- (ED09-0253-15) The Space Shuttle Discovery is parked within the Mate-Demate Device gantry at NASA’s Dryden Flight Research Center prior to begin turnaround processing for its ferry flight back to NASA's Kennedy Space Center in Florida. Discoloration on Discovery’s reinforced carbon-carbon nose cap gives evidence of the extreme heating it encountered during re-entry into the Earth’s atmosphere prior to landing Sept. 11. NASA photo / Tony Landis

Use of Functionalized Carbon Nanotubes for Covalent Attachment of Nanotubes to Silicon

NASA Technical Reports Server (NTRS)

Tour, James M.; Dyke, Christopher A.; Maya, Francisco; Stewart, Michael P.; Chen, Bo; Flatt, Austen K.

2012-01-01

The purpose of the invention is to covalently attach functionalized carbon nanotubes to silicon. This step allows for the introduction of carbon nanotubes onto all manner of silicon surfaces, and thereby introduction of carbon nano - tubes covalently into silicon-based devices, onto silicon particles, and onto silicon surfaces. Single-walled carbon nanotubes (SWNTs) dispersed as individuals in surfactant were functionalized. The nano - tube was first treated with 4-t-butylbenzenediazonium tetrafluoroborate to give increased solubility to the carbon nanotube; the second group attached to the sidewall of the nanotube has a silyl-protected terminal alkyne that is de-protected in situ. This gives a soluble carbon nanotube that has functional groups appended to the sidewall that can be attached covalently to silicon. This reaction was monitored by UV/vis/NJR to assure direct covalent functionalization.

Electrochemical Cell for Obtaining Oxygen from Carbon Dioxide Atmospheres

NASA Technical Reports Server (NTRS)

Hooker, Matthew; Rast, H. Edward; Rogers, Darren K.; Borja, Luis; Clark, Kevin; Fleming, Kimberly; Mcgurren, Michael; Oldaker, Tom; Sweet, Nanette

1989-01-01

To support human life on the Martian surface, an electrochemical device will be required to obtain oxygen from the carbon dioxide rich atmosphere. The electrolyte employed in such a device must be constructed from extremely thin, dense membranes to efficiently acquire the oxygen necessary to support life. A forming process used industrially in the production of multilayer capacitors and electronic substrates was adapted to form the thin membranes required. The process, known as the tape casting, involves the suspension consisting of solvents and binders. The suspension is passed under a blade, resulting in the production of ceramic membranes between 0.1 and 0.5 mm thick. Once fired, the stabilized zirconia membranes were assembled into the cell design by employing a zirconium phosphate solution as the sealing agent. The resulting ceramic-to-ceramic seals were found to be structurally sound and gas-tight. Furthermore, by using a zirconia-based solution to assemble the cell, the problem of a thermal expansion mismatch was alleviated. By adopting an industrial forming process to produce thin membranes, an electrochemical cell for obtaining oxygen from carbon dioxide was produced. The proposed cell design is unique in that it does not require a complicated manifold system for separating the various gases present in this process, nor does it require a series of complex electrical connections. Thus, the device can reliably obtain the vital oxygen supply from the toxic carbon dioxide atmosphere.

On the design and fabrication of nanostructures and devices

NASA Astrophysics Data System (ADS)

Wei, Wei

Nanotechnology is emerging into a new frontier in science and technology with potential impact on every aspect of human life. One of the major breakthroughs in today's nanotechnology is the discovery and preparation of new classes of nanomaterials and nanostructures. A large number of nanomaterials and nanostructures are synthesized and characterized with either new or profoundly enhanced properties or phenomena. However, there are several major challenges ahead need to be overcome before any substantial benefits can be brought to the market. One of the challenges that we need to address today is how to effectively integrate useful nanomaterials and nanostrucrures into functional devices and systems. Our mother nature gives us a classic example of how living organisms are built. Starting from a single cell, through its division and growth, it can self-assemble and become functional tissues and organs. Similar self-assemble approach has been adopted as a nano-fabrication technique to assemble nanomaterials and nanostructures into functional nanodevices. This technique has advantages of high precision and nanometer scale resolution. However, it requires a lot of effort to construct a single device and since the properties of individual nanostructures can be different, the fabricated devices may have different properties. In this dissertation, we design and fabricate nanostructures and devices using novel microfabrication techniques. In the first part of the dissertation, the design and fabrication of a variety of nanostructures, such as metal nanowires array, polymer nanowells, and nanostructured surfaces are discussed. In the second part, carbon nanotubes as a novel material has been explored as an example to demonstrate the integration of nanomaterials with novel microfabrication techniques to form a functional device. First, a resistive heating technique is developed to grow carbon nanotubes in localized regions, such as a nichrome heating coil. Then, MEMS micro-heating structures are designed for patterned carbon nanotubes film growth. At last, a MEMS sensor device using in-situ grown carbon nanotubes film as a sensing element is developed. The sensor shows sensitivity to hydrogen gas down to 100 ppm. A hypothetic model based on contact resistance modulation is presented to explain the observed sensing properties.

Synthesis of monolithic graphene – graphite integrated electronics

PubMed Central

Park, Jang-Ung; Nam, SungWoo; Lee, Mi-Sun; Lieber, Charles M.

2013-01-01

Encoding electronic functionality into nanoscale elements during chemical synthesis has been extensively explored over the past decade as the key to developing integrated nanosystems1 with functions defined by synthesis2-6. Graphene7-12 has been recently explored as a two-dimensional nanoscale material, and has demonstrated simple device functions based on conventional top-down fabrication13-20. However, the synthetic approach to encoding electronic functionality and thus enabling an entire integrated graphene electronics in a chemical synthesis had not previously been demonstrated. Here we report an unconventional approach for the synthesis of monolithically-integrated electronic devices based on graphene and graphite. Spatial patterning of heterogeneous catalyst metals permits the selective growth of graphene and graphite, with controlled number of graphene layers. Graphene transistor arrays with graphitic electrodes and interconnects were formed from synthesis. These functional, all-carbon structures were transferrable onto a variety of substrates. The integrated transistor arrays were used to demonstrate real-time, multiplexed chemical sensing, and more significantly, multiple carbon layers of the graphene-graphite device components were vertically assembled to form a three-dimensional flexible structure which served as a top-gate transistor array. These results represent a substantial progress towards encoding electronic functionality via chemical synthesis and suggest future promise for one-step integration of graphene-graphite based electronics. PMID:22101813

Synthesis of monolithic graphene-graphite integrated electronics.

PubMed

Park, Jang-Ung; Nam, SungWoo; Lee, Mi-Sun; Lieber, Charles M

2011-11-20

Encoding electronic functionality into nanoscale elements during chemical synthesis has been extensively explored over the past decade as the key to developing integrated nanosystems with functions defined by synthesis. Graphene has been recently explored as a two-dimensional nanoscale material, and has demonstrated simple device functions based on conventional top-down fabrication. However, the synthetic approach to encoding electronic functionality and thus enabling an entire integrated graphene electronics in a chemical synthesis had not previously been demonstrated. Here we report an unconventional approach for the synthesis of monolithically integrated electronic devices based on graphene and graphite. Spatial patterning of heterogeneous metal catalysts permits the selective growth of graphene and graphite, with a controlled number of graphene layers. Graphene transistor arrays with graphitic electrodes and interconnects were formed from the synthesis. These functional, all-carbon structures were transferable onto a variety of substrates. The integrated transistor arrays were used to demonstrate real-time, multiplexed chemical sensing and more significantly, multiple carbon layers of the graphene-graphite device components were vertically assembled to form a three-dimensional flexible structure which served as a top-gate transistor array. These results represent substantial progress towards encoding electronic functionality through chemical synthesis and suggest the future promise of one-step integration of graphene-graphite based electronics.

Poly(3,3‴-didodecylquarterthiophene) field effect transistors with single-walled carbon nanotube based source and drain electrodes

NASA Astrophysics Data System (ADS)

Zhang, Yuan Yuan; Shi, Yumeng; Chen, Fuming; Mhaisalkar, S. G.; Li, Lain-Jong; Ong, Beng S.; Wu, Yiliang

2007-11-01

A solution processable method for employing single-walled carbon nanotubes (SWCNTs) as bottom contact source/drain electrodes for a significant reduction of contact resistance in poly(3,3‴-didodecylquarterthiophene) based organic field effect transistors (OFETs) is proposed. A two order of magnitude reduction in contact resistance and up to a threefold improvement in field effect mobilities were observed in SWCNT contacted OFETs as opposed to similar devices with gold source/drain electrodes. Based on Kelvin probe measurements, this improvement was attributed to a reduction in the Schottky barrier for hole injection into organic semiconductor.

Fabrication of Graphene on Kevlar Supercapacitor Electrodes

DTIC Science & Technology

2011-05-01

fabricated with graphene to investigate its applicability for energy storage devices, as this carbon- based material has a large surface area and...Distribution List 14 iv List of Figures Figure 1. Dip-and-dry technique applied to Kevlar- based electrodes...2  Figure 2. Three-electrode system used for the CV measurements. The (1) working electrode was the Kevlar- based electrode; (2) the counter

Small diameter carbon nanopipettes

NASA Astrophysics Data System (ADS)

Singhal, Riju; Bhattacharyya, Sayan; Orynbayeva, Zulfiya; Vitol, Elina; Friedman, Gary; Gogotsi, Yury

2010-01-01

Nanoscale multifunctional carbon probes facilitate cellular studies due to their small size, which makes it possible to interrogate organelles within living cells in a minimally invasive fashion. However, connecting nanotubes to macroscopic devices and constructing an integrated system for the purpose of fluid and electrical signal transfer is challenging, as is often the case with nanoscale components. We describe a non-catalytic chemical vapor deposition based method for batch fabrication of integrated multifunctional carbon nanopipettes (CNPs) with tip diameters much smaller (10-30 nm) than previously reported (200 nm and above) and approaching those observed for multiwalled carbon nanotubes. This eliminates the need for complicated attachment/assembly of nanotubes into nanofluidic devices. Variable tip geometries and structures were obtained by controlled deposition of carbon inside and outside quartz pipettes. We have shown that the capillary length and gas flow rate have a marked effect on the carbon deposition. This gives us a flexible protocol, useful for growing carbon layers of different thicknesses at selective locations on a glass pipette to yield a large variety of cellular probes in bulk quantities. The CNPs possess an open channel for fluid transfer with the carbon deposited inside at 875 °C behaving like an amorphous semiconductor. Vacuum annealing of the CNP tips at temperatures up to 2000 °C yields graphitic carbon structures with an increase in conductivity of two orders of magnitude. Penetration of the integrated carbon nanoprobes into cells was shown to produce minimal Ca2+ signals, fast recovery of basal Ca2+ levels and no adverse activation of the cellular metabolism during interrogation times as long as 0.5-1 h.

Small diameter carbon nanopipettes.

PubMed

Singhal, Riju; Bhattacharyya, Sayan; Orynbayeva, Zulfiya; Vitol, Elina; Friedman, Gary; Gogotsi, Yury

2010-01-08

Nanoscale multifunctional carbon probes facilitate cellular studies due to their small size, which makes it possible to interrogate organelles within living cells in a minimally invasive fashion. However, connecting nanotubes to macroscopic devices and constructing an integrated system for the purpose of fluid and electrical signal transfer is challenging, as is often the case with nanoscale components. We describe a non-catalytic chemical vapor deposition based method for batch fabrication of integrated multifunctional carbon nanopipettes (CNPs) with tip diameters much smaller (10-30 nm) than previously reported (200 nm and above) and approaching those observed for multiwalled carbon nanotubes. This eliminates the need for complicated attachment/assembly of nanotubes into nanofluidic devices. Variable tip geometries and structures were obtained by controlled deposition of carbon inside and outside quartz pipettes. We have shown that the capillary length and gas flow rate have a marked effect on the carbon deposition. This gives us a flexible protocol, useful for growing carbon layers of different thicknesses at selective locations on a glass pipette to yield a large variety of cellular probes in bulk quantities. The CNPs possess an open channel for fluid transfer with the carbon deposited inside at 875 degrees C behaving like an amorphous semiconductor. Vacuum annealing of the CNP tips at temperatures up to 2000 degrees C yields graphitic carbon structures with an increase in conductivity of two orders of magnitude. Penetration of the integrated carbon nanoprobes into cells was shown to produce minimal Ca(2+) signals, fast recovery of basal Ca(2+) levels and no adverse activation of the cellular metabolism during interrogation times as long as 0.5-1 h.

Large-scale and patternable graphene: direct transformation of amorphous carbon film into graphene/graphite on insulators via Cu mediation engineering and its application to all-carbon based devices

NASA Astrophysics Data System (ADS)

Chen, Yu-Ze; Medina, Henry; Lin, Hung-Chiao; Tsai, Hung-Wei; Su, Teng-Yu; Chueh, Yu-Lun

2015-01-01

Chemical vapour deposition of graphene was the preferred way to synthesize graphene for multiple applications. However, several problems related to transfer processes, such as wrinkles, cleanness and scratches, have limited its application at the industrial scale. Intense research was triggered into developing alternative synthesis methods to directly deposit graphene on insulators at low cost with high uniformity and large area. In this work, we demonstrate a new concept to directly achieve growth of graphene on non-metal substrates. By exposing an amorphous carbon (a-C) film in Cu gaseous molecules after annealing at 850 °C, the carbon (a-C) film surprisingly undergoes a noticeable transformation to crystalline graphene. Furthermore, the thickness of graphene could be controlled, depending on the thickness of the pre-deposited a-C film. The transformation mechanism was investigated and explained in detail. This approach enables development of a one-step process to fabricate electrical devices made of all carbon material, highlighting the uniqueness of the novel approach for developing graphene electronic devices. Interestingly, the carbon electrodes made directly on the graphene layer by our approach offer a good ohmic contact compared with the Schottky barriers usually observed on graphene devices using metals as electrodes.Chemical vapour deposition of graphene was the preferred way to synthesize graphene for multiple applications. However, several problems related to transfer processes, such as wrinkles, cleanness and scratches, have limited its application at the industrial scale. Intense research was triggered into developing alternative synthesis methods to directly deposit graphene on insulators at low cost with high uniformity and large area. In this work, we demonstrate a new concept to directly achieve growth of graphene on non-metal substrates. By exposing an amorphous carbon (a-C) film in Cu gaseous molecules after annealing at 850 °C, the carbon (a-C) film surprisingly undergoes a noticeable transformation to crystalline graphene. Furthermore, the thickness of graphene could be controlled, depending on the thickness of the pre-deposited a-C film. The transformation mechanism was investigated and explained in detail. This approach enables development of a one-step process to fabricate electrical devices made of all carbon material, highlighting the uniqueness of the novel approach for developing graphene electronic devices. Interestingly, the carbon electrodes made directly on the graphene layer by our approach offer a good ohmic contact compared with the Schottky barriers usually observed on graphene devices using metals as electrodes. Electronic supplementary information (ESI) available: Experimental methods; pictures of a new quartz tube and an aged quartz tube before and after annealing Cu foil at 1025 °C for 2 h; Raman spectrum of as-deposited a-C layer; XPS depth profiles of 25 nm-thick pre-deposited a-C film after annealing in the presence of Cu gaseous molecules and the corresponding transformation ratios; ICP-MS results of Cu gaseous molecules captured by the formation of the Ni-Cu alloy; SEM-EDS results of samples with different thicknesses of pre-deposited a-C films; UV-Vis spectrum of the graphene directly transformed from the 5 nm-thick pre-deposited a-C film on quartz substrate. See DOI: 10.1039/c4nr04627g

Methods for forming particles from single source precursors

DOEpatents

Fox, Robert V [Idaho Falls, ID; Rodriguez, Rene G [Pocatello, ID; Pak, Joshua [Pocatello, ID

2011-08-23

Single source precursors are subjected to carbon dioxide to form particles of material. The carbon dioxide may be in a supercritical state. Single source precursors also may be subjected to supercritical fluids other than supercritical carbon dioxide to form particles of material. The methods may be used to form nanoparticles. In some embodiments, the methods are used to form chalcopyrite materials. Devices such as, for example, semiconductor devices may be fabricated that include such particles. Methods of forming semiconductor devices include subjecting single source precursors to carbon dioxide to form particles of semiconductor material, and establishing electrical contact between the particles and an electrode.

40 CFR Table 3 to Subpart Mmm of... - Monitoring Requirements for Control Devices a

Code of Federal Regulations, 2013 CFR

2013-07-01

... regeneration stream mass or volumetric flow during carbon bed regeneration cycle(s) 1. For each regeneration cycle, record the total regeneration stream mass or volumetric flow. Carbon bed temperature monitoring device 2. Temperature of carbon bed after regeneration 2. For each regeneration cycle, record the maximum...

40 CFR Table 3 to Subpart Mmm of... - Monitoring Requirements for Control Devices a

Code of Federal Regulations, 2014 CFR

2014-07-01

... regeneration stream mass or volumetric flow during carbon bed regeneration cycle(s) 1. For each regeneration cycle, record the total regeneration stream mass or volumetric flow. Carbon bed temperature monitoring device 2. Temperature of carbon bed after regeneration 2. For each regeneration cycle, record the maximum...

Carbon-Nanotube Schottky Diodes

NASA Technical Reports Server (NTRS)

Manohara, Harish; Wong, Eric; Schlecht, Erich; Hunt, Brian; Siegel, Peter

2006-01-01

Schottky diodes based on semiconducting single-walled carbon nanotubes are being developed as essential components of the next generation of submillimeter-wave sensors and sources. Initial performance predictions have shown that the performance characteristics of these devices can exceed those of the state-of-the-art solid-state Schottky diodes that have been the components of choice for room-temperature submillimeter-wave sensors for more than 50 years. For state-of-the-art Schottky diodes used as detectors at frequencies above a few hundred gigahertz, the inherent parasitic capacitances associated with their semiconductor junction areas and the resistances associated with low electron mobilities limit achievable sensitivity. The performance of such a detector falls off approximately exponentially with frequency above 500 GHz. Moreover, when used as frequency multipliers for generating signals, state-of-the-art solid-state Schottky diodes exhibit extremely low efficiencies, generally putting out only micro-watts of power at frequencies up to 1.5 THz. The shortcomings of the state-of-the-art solid-state Schottky diodes can be overcome by exploiting the unique electronic properties of semiconducting carbon nanotubes. A single-walled carbon nanotube can be metallic or semiconducting, depending on its chirality, and exhibits high electron mobility (recently reported to be approx.= 2x10(exp 5)sq cm/V-s) and low parasitic capacitance. Because of the narrowness of nanotubes, Schottky diodes based on carbon nanotubes have ultra-small junction areas (of the order of a few square nanometers) and consequent junction capacitances of the order of 10(exp -18) F, which translates to cutoff frequency >5 THz. Because the turn-on power levels of these devices are very low (of the order of nano-watts), the input power levels needed for pumping local oscillators containing these devices should be lower than those needed for local oscillators containing state-of-the-art solid-state Schottky diodes.

Scalability of carbon-nanotube-based thin film transistors for flexible electronic devices manufactured using an all roll-to-roll gravure printing system

PubMed Central

Koo, Hyunmo; Lee, Wookyu; Choi, Younchang; Sun, Junfeng; Bak, Jina; Noh, Jinsoo; Subramanian, Vivek; Azuma, Yasuo; Majima, Yutaka; Cho, Gyoujin

2015-01-01

To demonstrate that roll-to-roll (R2R) gravure printing is a suitable advanced manufacturing method for flexible thin film transistor (TFT)-based electronic circuits, three different nanomaterial-based inks (silver nanoparticles, BaTiO3 nanoparticles and single-walled carbon nanotubes (SWNTs)) were selected and optimized to enable the realization of fully printed SWNT-based TFTs (SWNT-TFTs) on 150-m-long rolls of 0.25-m-wide poly(ethylene terephthalate) (PET). SWNT-TFTs with 5 different channel lengths, namely, 30, 80, 130, 180, and 230 μm, were fabricated using a printing speed of 8 m/min. These SWNT-TFTs were characterized, and the obtained electrical parameters were related to major mechanical factors such as web tension, registration accuracy, impression roll pressure and printing speed to determine whether these mechanical factors were the sources of the observed device-to-device variations. By utilizing the electrical parameters from the SWNT-TFTs, a Monte Carlo simulation for a 1-bit adder circuit, as a reference, was conducted to demonstrate that functional circuits with reasonable complexity can indeed be manufactured using R2R gravure printing. The simulation results suggest that circuits with complexity, similar to the full adder circuit, can be printed with a 76% circuit yield if threshold voltage (Vth) variations of less than 30% can be maintained. PMID:26411839

Carbon material based microelectromechanical system (MEMS): Fabrication and devices

NASA Astrophysics Data System (ADS)

Xu, Wenjun

This PhD dissertation presents the exploration and development of two carbon materials, carbon nanotubes (CNTs) and carbon fiber (CF), as either key functional components or unconventional substrates for a variety of MEMS applications. Their performance in three different types of MEMS devices, namely, strain/stress sensors, vibration-powered generators and fiber solar cells, were evaluated and the working mechanisms of these two non-traditional materials in these systems were discussed. The work may potentially enable the development of new types of carbon-MEMS devices. Carbon nanotubes were selected from the carbon family due to several advantageous characteristics that this nanomaterial offers. They carry extremely high mechanical strength (Ey=1TPa), superior electrical properties (current density of 4x109 A/cm2), exceptional piezoresistivity (G=2900), and unique spatial format (high aspect ratio hollow nanocylinder), among other properties. If properly utilized, all these merits can give rise to a variety of new types of carbon nanotube based micro- and nanoelectronics that can greatly fulfill the need for the next generation of faster, smaller and better devices. However, before these functions can be fully realized, one substantial issue to cope with is how to implement CNTs into these systems in an effective and controllable fashion. Challenges associated with CNTs integration include very poor dispersibility in solvents, lack of melting/sublimation point, and unfavorable rheology with regard to mixing and processing highly viscous, CNT-loaded polymer solutions. These issues hinder the practical progress of CNTs both in a lab scale and in the industrial level. To this end, a MEMS-assisted electrophoretic deposition technique was developed, aiming to achieve controlled integration of CNT into both conventional and flexible microsystems at room temperature with a relatively high throughput. MEMS technology has demonstrated strong capability in developing silicon and metal based microsystems. In this thesis, this mature technique was exploited to generate a variety of microelectrode structures to facilitate the micropatterning and manipulation of the CNTs. Selective deposition of electrically charged CNTs onto desired locations was realized in an EPD process through patterning of electric field lines created by the microelectrodes fabricated through MEMS techniques. A variety of 2-D and 3-D micropatterns of CNTs with waferscale areas have been successfully achieved in both rigid and elastic systems. The thickness and morphology of the generated CNT patterns was found to be readily controllable through the parameters of the fabrication process. Studies also showed that for this technique, high surface hydrophobicity of the non-conductive regions in microstructures was critical to accomplish well-defined selective micropatterning of CNTs. Upon clearing the hurdles of the CNT manipulation, a patterned PDMS/CNT nanocomposite was fabricated through the aforementioned approach and was incorporated, investigated and validated in elastic force/strain microsensors. The gauge factor of the sensor exhibited a strong dependence on both the initial resistance of the device and the applied strain. Detailed analysis of the data suggests that the piezoresistive effect of this specially constructed bi-layer composite could be due to three mechanisms, and the sensing mechanism may vary when physical properties of the CNT network embedded in the polymer matrix alter. The feasibility of the PDSM/CNT composite being utilized as an elastic electret was further explored. The nanocomposite composed of these two non-traditional electret materials exhibited electret characteristics with reasonable charge storage stability when charged using a corona discharge. The power generation capacity of the corona-charged composite has been characterized and successfully demonstrated in both a ball drop experiment and cyclic mechanical load experiments. Lastly, in an effort to develop carbon-material-based substrates for MEMS applications, a carbon fiber-based poly-Si solar cell was designed, fabricated and investigated. This fiber-type photovoltaics (PV) takes advantage of the excellent thermal stability, electrical conductivity and spatial format of the CF, which allows CF to serve as both the building block and the electrode in the PV configuration. The photovoltaic effects of the fiber PV were demonstrated with an open-circuit voltage of 0.14 V, a short-circuit current density of 1.7 mA/cm2, and output power density of 0.059mW/cm2 . The issues of this system were discussed as well.

21 CFR 884.1300 - Uterotubal carbon dioxide insufflator and accessories.

Code of Federal Regulations, 2011 CFR

2011-04-01

... 21 Food and Drugs 8 2011-04-01 2011-04-01 false Uterotubal carbon dioxide insufflator and accessories. 884.1300 Section 884.1300 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES OBSTETRICAL AND GYNECOLOGICAL DEVICES Obstetrical and Gynecological Diagnostic Devices § 884.1300...

21 CFR 884.1300 - Uterotubal carbon dioxide insufflator and accessories.

Code of Federal Regulations, 2012 CFR

2012-04-01

... 21 Food and Drugs 8 2012-04-01 2012-04-01 false Uterotubal carbon dioxide insufflator and accessories. 884.1300 Section 884.1300 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES OBSTETRICAL AND GYNECOLOGICAL DEVICES Obstetrical and Gynecological Diagnostic Devices § 884.1300...

Functionalized carbon micro/nanostructures for biomolecular detection

NASA Astrophysics Data System (ADS)

Penmatsa, Varun

Advancements in the micro-and nano-scale fabrication techniques have opened up new avenues for the development of portable, scalable and easier-to-use biosensors. Over the last few years, electrodes made of carbon have been widely used as sensing units in biosensors due to their attractive physiochemical properties. The aim of this research is to investigate different strategies to develop functionalized high surface carbon micro/nano-structures for electrochemical and biosensing devices. High aspect ratio three-dimensional carbon microarrays were fabricated via carbon microelectromechanical systems (C-MEMS) technique, which is based on pyrolyzing pre-patterned organic photoresist polymers. To further increase the surface area of the carbon microstructures, surface porosity was introduced by two strategies, i.e. (i) using F127 as porogen and (ii) oxygen reactive ion etch (RIE) treatment. Electrochemical characterization showed that porous carbon thin film electrodes prepared by using F127 as porogen had an effective surface area (Aeff 185%) compared to the conventional carbon electrode. To achieve enhanced electrochemical sensitivity for C-MEMS based functional devices, graphene was conformally coated onto high aspect ratio three-dimensional (3D) carbon micropillar arrays using electrostatic spray deposition (ESD) technique. The amperometric response of graphene/carbon micropillar electrode arrays exhibited higher electrochemical activity, improved charge transfer and a linear response towards H2O2 detection between 250μM to 5.5mM. Furthermore, carbon structures with dimensions from 50 nano-to micrometer level have been fabricated by pyrolyzing photo-nanoimprint lithography patterned organic resist polymer. Microstructure, elemental composition and resistivity characterization of the carbon nanostructures produced by this process were very similar to conventional photoresist derived carbon. Surface functionalization of the carbon nanostructures was performed using direct amination technique. Considering the need for requisite functional groups to covalently attach bioreceptors on the carbon surface for biomolecule detection, different oxidation techniques were compared to study the types of carbon-oxygen groups formed on the surface and their percentages with respect to different oxidation pretreatment times. Finally, a label-free detection strategy using signaling aptamer/protein binding complex for platelet-derived growth factor oncoprotein detection on functionalized three-dimensional carbon microarrays platform was demonstrated. The sensor showed near linear relationship between the relative fluorescence difference and protein concentration even in the sub-nanomolar range with an excellent detection limit of 5 pmol.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Konov, V I

The properties of new carbon materials (single-crystal and polycrystalline CVD diamond films and wafers, single-wall carbon nanotubes and graphene) and the prospects of their use as optical elements and devices are discussed. (optical elements of laser devices)

Fabrication and evaluation of polymeric early-warning fire-alarm devices. [combustion products

NASA Technical Reports Server (NTRS)

Senturia, S. D.

1975-01-01

The electrical resistivities were investigated of some polymers known to be enhanced by the presence of certain gases. This was done to make a device capable of providing early warning to fire through its response with the gases produced in the early phases of combustion. Eight polymers were investigated: poly(phenyl acetylene), poly(p-aminophenyl acetylene), poly(p-nitrophenyl acetylene), poly(p-formamidophenyl acetylene), poly(ethynyl ferrocene), poly(ethynyl carborane), poly(ethynyl pyridine), and the polymer made from 1,2,3,6 tetramethyl pyridazine. A total of 40 usable thin-film sandwich devices and a total of 70 usable interdigitated-electrode lock-and-key devices were fabricated. The sandwich devices were used for measurements of contact linearity, polymer conductivity, and polymer dielectric constant. The lock-and-key devices were used to determine the response of the polymers to a spectrum of gases that included ammonia, carbon nonoxide, carbon dioxide, sulfur dioxide, ethylene, acrolein, water vapor, and normal laboratory air. Strongest responses were to water vapor, ammonia, and acrolein, and depending on the polymer, weaker responses to carbon dioxide, sulfur dioxide, and carbon monoxide were observed. A quantitative theory of device operation, capable of accounting for observed device leakage current and sensitivity, was developed. A prototype detection/alarm system was designed and built for use in demonstrating sensor performance.

Characterization and electrochemical application of carbon materials based on poly(phenylene oxide)

NASA Astrophysics Data System (ADS)

Gray, Hunter

Carbon materials possess excellent electrical and surface properties for the next generation of energy storage devices. Polymers provide a carbon rich and tailorable precursor for the production of carbon materials. Therefore, activated carbons were prepared from poly(2,6-dimethyl-1,4-phenylene oxide) (PPO) via a three step process: thermal oxidation, carbonization, and activation with KOH. The activated carbons are predominately microporous with BET specific surface areas up to 2638 m2/g. Impedance spectroscopy revealed these carbons possess electrical conductivities comparable to commercial carbon blacks and consequently were employed in thin-film composite electrodes in electrochemical double-layer capacitors. Cyclic voltammetry confirmed maximum specific capacitances of 13.23 F/g and 2.848 F/g for aqueous and organic electrolyte systems, respectively. Additionally, carbon nanotubes were synthesized from PPO and other polymers with a nickel catalyst via chemical vapor deposition as revealed by transmission electron microscopy. This is the first report of carbon nanotubes produced from PPO.

Current trends in nanomaterial embedded field effect transistor-based biosensor.

PubMed

Nehra, Anuj; Pal Singh, Krishna

2015-12-15

Recently, as metal-, polymer-, and carbon-based biocompatible nanomaterials have been increasingly incorporated into biosensing applications, with various nanostructures having been used to increase the efficacy and sensitivity of most of the detecting devices, including field effect transistor (FET)-based devices. These nanomaterial-based methods also became the ideal for the amalgamation of biomolecules, especially for the fabrication of ultrasensitive, low-cost, and robust FET-based biosensors; these are categorically very successful at binding the target specified entities in the confined gated micro-region for high functionality. Furthermore, the contemplation of nanomaterial-based FET biosensors to various applications encompasses the desire for detection of many targets with high selectivity, and specificity. We assess how such devices have empowered the achievement of elevated biosensor performance in terms of high sensitivity, selectivity and low detection limits. We review the recent literature here to illustrate the diversity of FET-based biosensors, based on various kinds of nanomaterials in different applications and sum up that graphene or its assisted composite based FET devices are comparatively more efficient and sensitive with highest signal to noise ratio. Lastly, the future prospects and limitations of the field are also discussed. Copyright © 2015 Elsevier B.V. All rights reserved.

Resistive and Capacitive γ-Ray Dosimeters Based On Triggered Depolymerization in Carbon Nanotube Composites.

PubMed

Zeininger, Lukas; He, Maggie; Hobson, Stephen T; Swager, Timothy M

2018-05-25

We report γ-ray dosimeters using carbon nanotubes wrapped with metastable poly(olefin sulfone)s (POSs) that readily depolymerize when exposed to ionizing radiation. New POSs, designed for wrapping single-walled carbon nanotubes (SWCNTs), are synthesized and characterized. The resulting POS-SWCNT composites serve as the active transducer in a novel class of γ-ray dosimeters. In our devices, polymer degradation results in immediate changes in the electronic potential of the POS-SWCNT active layers by decreasing the electron tunneling barriers between individualized tubes and by creating enhanced cofacial π-π electron contacts. By incorporating the SWCNT-POS composites into small resistive device platforms, we establish a rare example of real-time detection and dosimetry of radioactive ionizing radiation using organic-based materials. We show that the sensitivity of our platform closely depends on the intrinsic stability of the polymer matrix, the opacity toward γ-rays, and the dispersion efficiency (i.e., the individualization and isolation of the individual SWCNT charge carriers). Resistance decreases up to 65% after irradiation with a 40 krad dose demonstrates the high sensitivity of this novel class of γ-ray sensors. In addition, the detection mechanism was evaluated using a commercial capacitive device platform. The ease of fabrication and low power consumption of these small and inexpensive sensor platforms combined with appealing sensitivity parameters establishes the potential of the poly(olefin sulfone)-SWCNT composites to serve as a new transduction material in γ-ray sensor applications.

Arrays of Carbon Nanotubes as RF Filters in Waveguides

NASA Technical Reports Server (NTRS)

Hoppe, Daniel; Hunt, Brian; Hoenk, Michael; Noca, Flavio; Xu, Jimmy

2003-01-01

Brushlike arrays of carbon nanotubes embedded in microstrip waveguides provide highly efficient (high-Q) mechanical resonators that will enable ultraminiature radio-frequency (RF) integrated circuits. In its basic form, this invention is an RF filter based on a carbon nanotube array embedded in a microstrip (or coplanar) waveguide, as shown in Figure 1. In addition, arrays of these nanotube-based RF filters can be used as an RF filter bank. Applications of this new nanotube array device include a variety of communications and signal-processing technologies. High-Q resonators are essential for stable, low-noise communications, and radar applications. Mechanical oscillators can exhibit orders of magnitude higher Qs than electronic resonant circuits, which are limited by resistive losses. This has motivated the development of a variety of mechanical resonators, including bulk acoustic wave (BAW) resonators, surface acoustic wave (SAW) resonators, and Si and SiC micromachined resonators (known as microelectromechanical systems or MEMS). There is also a strong push to extend the resonant frequencies of these oscillators into the GHz regime of state-of-the-art electronics. Unfortunately, the BAW and SAW devices tend to be large and are not easily integrated into electronic circuits. MEMS structures have been integrated into circuits, but efforts to extend MEMS resonant frequencies into the GHz regime have been difficult because of scaling problems with the capacitively-coupled drive and readout. In contrast, the proposed devices would be much smaller and hence could be more readily incorporated into advanced RF (more specifically, microwave) integrated circuits.

Low-loss saturable absorbers based on tapered fibers embedded in carbon nanotube/polymer composites

NASA Astrophysics Data System (ADS)

Martinez, Amos; Al Araimi, Mohammed; Dmitriev, Artemiy; Lutsyk, Petro; Li, Shen; Mou, Chengbo; Rozhin, Alexey; Sumetsky, Misha; Turitsyn, Sergei

2017-12-01

The emergence of low-dimensional materials has opened new opportunities in the fabrication of compact nonlinear photonic devices. Single-walled carbon nanotubes were among the first of those materials to attract the attention of the photonics community owing to their high third order susceptibility, broadband operation, and ultrafast response. Saturable absorption, in particular, has become a widespread application for nanotubes in the mode-locking of a fiber laser where they are used as nonlinear passive amplitude modulators to initiate pulsed operation. Numerous approaches have been proposed for the integration of nanotubes in fiber systems; these can be divided into those that rely on direct interaction (where the nanotubes are sandwiched between fiber connectors) and those that rely on lateral interaction with the evanescence field of the propagating wave. Tapered fibers, in particular, offer excellent flexibility to adjust the nonlinearity of nanotube-based devices but suffer from high losses (typically exceeding 50%) and poor saturable to non-saturable absorption ratios (typically above 1:5). In this paper, we propose a method to fabricate carbon nanotube saturable absorbers with controllable saturation power, low-losses (as low as 15%), and large saturable to non-saturable loss ratios approaching 1:1. This is achieved by optimizing the procedure of embedding tapered fibers in low-refractive index polymers. In addition, this study sheds light in the operation of these devices, highlighting a trade-off between losses and saturation power and providing guidelines for the design of saturable absorbers according to their application.

Three-Dimensional Conductive Nanocomposites Based on Multiwalled Carbon Nanotube Networks and PEDOT:PSS as a Flexible Transparent Electrode for Optoelectronics.

PubMed

Cho, Er-Chieh; Li, Chiu-Ping; Huang, Jui-Hsiung; Lee, Kuen-Chan; Huang, Jen-Hsien

2015-06-03

We have synthesized conductive nanocomposites composed of multiwalled carbon nanotubes (MWCNTs) and Au nanoparticles (NPs). The Au NPs with an average size of approximately 4.3 nm are uniformly anchored on the MWCNT. After being exposed to microwave (MW) plasma irradiation, the anchored Au NPs melt and fuse, leading to larger aggregates (34 nm) that can connect the MWCNT forming a three-dimensional conducting network. The formation of a continuous MWCNT network can produce more a conductive pathway, leading to lower sheet resistance. When the Au-MWCNT is dispersed in the highly conductive polymer, poly(ethylene dioxythiophene):polystyrenesulfonate ( PSS), we can obtain solution-processable composite formulations for the preparation of a flexible transparent electrode. The resulting Au-MWCNT/PEDOT:PSS hybrid films possess a sheet resistance of 51 Ω/sq with a transmittance of 86.2% at 550 nm. We also fabricate flexible organic solar cells and electrochromic devices to demonstrate the potential use of the as-prepared composite electrodes. Compared with the indium tin oxide-based devices, both the solar cells and electrochromic devices with the composites incorporated as a transparent electrode deliver comparable performance.

Novel planar field emission of ultra-thin individual carbon nanotubes.

PubMed

Song, Xuefeng; Gao, Jingyun; Fu, Qiang; Xu, Jun; Zhao, Qing; Yu, Dapeng

2009-10-07

In this work, we proposed and realized a new prototype of planar field emission device based on as-grown individual carbon nanotubes (CNTs) on the surface of a Si-SiO2 substrate. The anode, cathode and the CNT tip all lie on the same surface, so the electron emission is reduced from three-dimensional to two-dimensional. The benefits of such a design include usage of thinner CNT emitters, integrity with planar technology, stable construction, better heat dissipation, etc. A tip-to-tip field emission device was presented besides the tip-to-electrode one. Real-time, in situ observation of the planar field emission was realized in a scanning electron microscope (SEM). Measurements showed that the minimum voltage for 10 nA field emission current was only 8.0 V and the maximum emission current density in an individual CNT emitter (1.0 nm in diameter) exceeded 5.7 x 10(8) A cm(-2). These results stand out in the comparison with recent works on individual CNT field emission, indicating that the planar devices based on ultra-thin individual CNTs are more competitive candidates for next-generation electron field emitters.

MnO2-Based Electrochemical Supercapacitors on Flexible Carbon Substrates

NASA Astrophysics Data System (ADS)

Tadjer, Marko J.; Mastro, Michael A.; Rojo, José M.; Mojena, Alberto Boscá; Calle, Fernando; Kub, Francis J.; Eddy, Charles R.

2014-04-01

Manganese dioxide films were grown on large area flexible carbon aerogel substrates. Characterization by x-ray diffraction confirmed α-MnO2 growth. Three types of films were compared as a function of hexamethylenetetramine (HMTA) concentration during growth. The highest concentration of HM TA produced MnO2 flower-like films, as observed by scanning electron microscopy, whose thickness and surface coverage lead to both a higher specific capacitance and higher series resistance. Specific capacitance was measured to be 64 F/g using a galvanostatic setup, compared to the 47 F/g-specific capacitance of the carbon aerogel substrate. Such supercapacitor devices can be fabricated on large area sheets of carbon aerogel to achieve high total capacitance.

Anomalous I-V curve for mono-atomic carbon chains

NASA Astrophysics Data System (ADS)

Song, Bo; Sanvito, Stefano; Fang, Haiping

2010-10-01

The electronic transport properties of mono-atomic carbon chains were studied theoretically using a combination of density functional theory and the non-equilibrium Green's functions method. The I-V curves for the chains composed of an even number of atoms and attached to gold electrodes through sulfur exhibit two plateaus where the current becomes bias independent. In contrast, when the number of carbon atoms in the chain is odd, the electric current simply increases monotonically with bias. This peculiar behavior is attributed to dimerization of the chains, directly resulting from their one-dimensional nature. The finding is expected to be helpful in designing molecular devices, such as carbon-chain-based transistors and sensors, for nanoscale and biological applications.

Plasma Enhanced Growth of Carbon Nanotubes For Ultrasensitive Biosensors

NASA Technical Reports Server (NTRS)

Cassell, Alan M.; Meyyappan, M.

2004-01-01

The multitude of considerations facing nanostructure growth and integration lends itself to combinatorial optimization approaches. Rapid optimization becomes even more important with wafer-scale growth and integration processes. Here we discuss methodology for developing plasma enhanced CVD growth techniques for achieving individual, vertically aligned carbon nanostructures that show excellent properties as ultrasensitive electrodes for nucleic acid detection. We utilize high throughput strategies for optimizing the upstream and downstream processing and integration of carbon nanotube electrodes as functional elements in various device types. An overview of ultrasensitive carbon nanotube based sensor arrays for electrochemical bio-sensing applications and the high throughput methodology utilized to combine novel electrode technology with conventional MEMS processing will be presented.

Plasma Enhanced Growth of Carbon Nanotubes For Ultrasensitive Biosensors

NASA Technical Reports Server (NTRS)

Cassell, Alan M.; Li, J.; Ye, Q.; Koehne, J.; Chen, H.; Meyyappan, M.

2004-01-01

The multitude of considerations facing nanostructure growth and integration lends itself to combinatorial optimization approaches. Rapid optimization becomes even more important with wafer-scale growth and integration processes. Here we discuss methodology for developing plasma enhanced CVD growth techniques for achieving individual, vertically aligned carbon nanostructures that show excellent properties as ultrasensitive electrodes for nucleic acid detection. We utilize high throughput strategies for optimizing the upstream and downstream processing and integration of carbon nanotube electrodes as functional elements in various device types. An overview of ultrasensitive carbon nanotube based sensor arrays for electrochemical biosensing applications and the high throughput methodology utilized to combine novel electrode technology with conventional MEMS processing will be presented.

Gas Sensors Based on Coated and Doped Carbon Nanotubes

NASA Technical Reports Server (NTRS)

Li, Jing; Meyyappan, Meyya

2008-01-01

Efforts are underway to develop inexpensive, low-power electronic sensors, based on single-walled carbon nanotubes (SWCNTs), for measuring part-per-million and part-per-billion of selected gases (small molecules) at room temperature. Chemically unmodified SWCNTs are mostly unresponsive to typical gases that one might wish to detect. However, the electrical resistances of SWCNTs can be made to vary with concentrations of gases of interest by coating or doping the SWCNTs with suitable materials. Accordingly, the basic idea of the present development efforts is to incorporate thus-treated SWCNTs into electronic devices that measure their electrical resistances.

Nanotechnology and textiles engineered by carbon nanotubes for the realization of advanced personal protective equipments

DOE Office of Scientific and Technical Information (OSTI.GOV)

Andretta, Antonio, E-mail: Antonio-Andretta@klopman.com; Terranova, Maria Letizia; Lavecchia, Teresa

2014-06-19

Carbon nanotubes (CNT) and CNT-based active materials have been used to assemble the gas sensing unit of innovative platforms able to detect toxic atmospheres developing in confined workplaces. The main goal of the project was to realize a full-featured, operator-friendly safety detection and monitoring system based on multifunctional textiles nanotechnologies. The fabricated sensing platform consists of a multiple gas detector coupled with a specifically designed telecommunication infrastructure. The portable device, totally integrated in the workwear, offers several advantages over the conventional safety tools employed in industrial work activities.

Nanotechnology and textiles engineered by carbon nanotubes for the realization of advanced personal protective equipments

NASA Astrophysics Data System (ADS)

Andretta, Antonio; Terranova, Maria Letizia; Lavecchia, Teresa; Gay, Stefano; Picano, Alfredo; Mascioletti, Alessandro; Stirpe, Daniele; Cucchiella, Cristian; Pascucci, Eddy; Dugnani, Giovanni; Gatti, Davide; Laria, Giuseppe; Codenotti, Barbara; Maldini, Giorgio; Roth, Siegmar; Passeri, Daniele; Rossi, Marco; Tamburri, Emanuela

2014-06-01

Carbon nanotubes (CNT) and CNT-based active materials have been used to assemble the gas sensing unit of innovative platforms able to detect toxic atmospheres developing in confined workplaces. The main goal of the project was to realize a full-featured, operator-friendly safety detection and monitoring system based on multifunctional textiles nanotechnologies. The fabricated sensing platform consists of a multiple gas detector coupled with a specifically designed telecommunication infrastructure. The portable device, totally integrated in the workwear, offers several advantages over the conventional safety tools employed in industrial work activities.

Printed energy storage devices by integration of electrodes and separators into single sheets of paper

NASA Astrophysics Data System (ADS)

Hu, Liangbing; Wu, Hui; Cui, Yi

2010-05-01

We report carbon nanotube thin film-based supercapacitors fabricated with printing methods, where electrodes and separators are integrated into single sheets of commercial paper. Carbon nanotube films are easily printed with Meyer rod coating or ink-jet printing onto a paper substrate due to the excellent ink absorption of paper. A specific capacity of 33 F/g at a high specific power of 250 000 W/kg is achieved with an organic electrolyte. Such a lightweight paper-based supercapacitor could be used to power paper electronics such as transistors or displays.

Graphene-Based Ultra-Light Batteries for Aircraft

NASA Technical Reports Server (NTRS)

Calle, Carlos I.; Kaner, Richard B.

2014-01-01

Develop a graphene-based ultracapacitor prototype that is flexible, thin, lightweight, durable, low cost, and safe and that will demonstrate the feasibility for use in aircraft center dot These graphene-based devices store charge on graphene sheets and take advantage of the large accessible surface area of graphene (2,600 m2/g) to increase the electrical energy that can be stored. center dot The proposed devices should have the electrical storage capacity of thin-film-ion batteries but with much shorter charge/discharge cycle times as well as longer lives center dot The proposed devices will be carbon-based and so will not have the same issues with flammability or toxicity as the standard lithium-based storage cells There are two main established methods for the storage and delivery of electrical energy: center dot Batteries - Store energy with electrochemical reactions - High energy densities - Slow charge/discharge cycles - Used in applications requiring large amounts of energy ? aircraft center dot Electrochemical capacitors - Store energy in electrochemical double layers - Fast charge/discharge cycles - Low energy densities - Used in electronics devices - Large capacitors are used in truck engine cranking

Monolithic quasi-solid-state dye-sensitized solar cells based on graphene modified mesoscopic carbon counter electrodes

NASA Astrophysics Data System (ADS)

Rong, Yaoguang; Li, Xiong; Liu, Guanghui; Wang, Heng; Ku, Zhiliang; Xu, Mi; Liu, Linfeng; Hu, Min; Yang, Ying; Han, Hongwei

2013-03-01

We have developed a monolithic quasi-solid-state dye-sensitized solar cell (DSSC) based on graphene modified mesoscopic carbon counter electrode (GC-CE), which offers a promising prospect for commercial applications. Based on the design of a triple layer structure, the TiO2 working electrode layer, ZrO2 spacer layer and carbon counter electrode (CE) layer are constructed on a single conducting glass substrate by screen-printing. The quasi-solid-state polymer gel electrolyte employs a polymer composite as the gelator and could effectively infiltrate into the porous layers. Fabricated with normal carbon counter electrode (NC-CE) containing graphite and carbon black, the device shows a power conversion efficiency (PCE) of 5.09% with the fill factor (FF) of 0.63 at 100 mW cm-2 AM1.5 illumination. When the NC-CE is modified with graphene sheets, the PCE and FF could be enhanced to 6.27% and 0.71, respectively. This improvement indicates excellent conductivity and high electrocatalytic activity of the graphene sheets, which have been considered as a promising platinum-free electrode material for DSSCs.

Carbon-Based Nanomaterials/Allotropes: A Glimpse of Their Synthesis, Properties and Some Applications

PubMed Central

Zainal, Zulkarnain; Yusof, Nor Azah

2018-01-01

Carbon in its single entity and various forms has been used in technology and human life for many centuries. Since prehistoric times, carbon-based materials such as graphite, charcoal and carbon black have been used as writing and drawing materials. In the past two and a half decades or so, conjugated carbon nanomaterials, especially carbon nanotubes, fullerenes, activated carbon and graphite have been used as energy materials due to their exclusive properties. Due to their outstanding chemical, mechanical, electrical and thermal properties, carbon nanostructures have recently found application in many diverse areas; including drug delivery, electronics, composite materials, sensors, field emission devices, energy storage and conversion, etc. Following the global energy outlook, it is forecasted that the world energy demand will double by 2050. This calls for a new and efficient means to double the energy supply in order to meet the challenges that forge ahead. Carbon nanomaterials are believed to be appropriate and promising (when used as energy materials) to cushion the threat. Consequently, the amazing properties of these materials and greatest potentials towards greener and environment friendly synthesis methods and industrial scale production of carbon nanostructured materials is undoubtedly necessary and can therefore be glimpsed as the focal point of many researchers in science and technology in the 21st century. This is based on the incredible future that lies ahead with these smart carbon-based materials. This review is determined to give a synopsis of new advances towards their synthesis, properties, and some applications as reported in the existing literatures. PMID:29438327

The development and characterization of a first generation carbon nanotube x-ray based microbeam radiation therapy system

NASA Astrophysics Data System (ADS)

Hadsell, Michael John, Jr.

Microbeam radiation therapy (MRT) is a new type of cancer treatment currently being studied at scattered synchrotron sites throughout the world. It has been shown to be capable of ablating aggressive brain tumors in rats while almost completely sparing the surrounding normal tissue. This promising technique has yet to find its way to the clinic, however, because the radiobiological mechanisms behind its efficacy are still largely unknown. This is partly due to the lack of a compact device that could facilitate more large scale research. The challenges inherent to creating a compact device lie within the structure of MRT, which uses parallel arrays of ultra high-dose, orthovoltage, microplanar beams on the order of 100mum thick and separated by four to ten times their width. Because of focal spot limitations, current commercial orthovoltage devices are simply not capable of creating such arrays at dose rates high enough for effective treatment while maintaining the microbeam pattern necessary to retain the high therapeutic ratio of the technique. Therefore, the development of a compact MRT device using carbon nanotube (CNT) cathode based X-ray technology is presented here. CNT cathodes have been shown to be capable of creating novel focal spot arrays on a single anode while being robust enough for long-term use in X-ray tubes. Using these cathodes, an X-ray tube with a single focal line has been created for the delivery of MRT dose distributions in radiobiological studies on small animals. In this work, the development process and final design of this specialized device will be detailed, along with the optimization and stabilization of its use for small animal studies. In addition, a detailed characterization of its final capabilities will be given; including a comprehensive measurement of its X-ray focal line dimensions, a description and evaluation of its collimator alignment and microbeam dimensions, and a full-scale phantom-based quantification of its dosimetric output. Finally, future project directions will be described briefly along with plans for a second generation device. Based on the results of this work, it is the author's belief that compact CNT MRT devices have definite commercialization potential for radiobiological research.

High Power Electric Double-Layer Capacitors based on Room-Temperature Ionic Liquids and Nanostructured Carbons

NASA Astrophysics Data System (ADS)

Perez, Carlos R.

The efficient storage of electrical energy constitutes both a fundamental challenge for 21st century science and an urgent requirement for the sustainability of our technological civilization. The push for cleaner renewable forms of energy production, such as solar and wind power, strongly depends on a concomitant development of suitable storage methods to pair with these intermittent sources, as well as for mobile applications, such as vehicles and personal electronics. In this regard, Electrochemical Double-Layer Capacitors (supercapacitors) represent a vibrant area of research due to their environmental friendliness, long lifetimes, high power capability, and relative underdevelopment when compared to electrochemical batteries. Currently supercapacitors have gravimetric energies one order of magnitude lower than similarly advanced batteries, while conversly enjoying a similar advantage over them in terms of power. The challenge is to increase the gravimentric energies and conserve the high power. On the material side, research focuses on highly porous supports and electrolytes, the critical components of supercapacitors. Through the use of electrolyte systems with a wider electrochemical stability window, as well as properly tailored carbon nanomaterials as electrodes, significant improvements in performance are possible. Room Temperature Ionic Liquids and Carbide-Derived Carbons are promising electrolytes and electrodes, respectively. RTILs have been shown to be stable at up to twice the voltage of organic solvent-salt systems currently employed in supercapacitors, and CDCs are tunable in pore structure, show good electrical conductivity, and superior demonstrated capability as electrode material. This work aims to better understand the interplay of electrode and electrolyte parameters, such as pore structure and ion size, in the ultimate performance of RTIL-based supercapacitors in terms of power, energy, and temperature of operation. For this purpose, carbon nanomaterials such as nanoporous CDC nanopowders, vertically aligned carbon nanotube arrays, and single wall carbon nanotube aerogels, were synthesized and used as electrodes, alongside RTIL electrolytes with systematically varying ion sizes and compositions. While electrode/electrolyte development can take place along parallel lines, both must be properly matched to the device's ultimate operating conditions and specific application. The resulting devices exhibit good performance characteristics, and the best temperature range of any electrochemical storage device to date.

EVALUATING A COMPOSITE CARTRIDGE FOR SMALL SYSTEM DRINKING WATER TREATMENT

EPA Science Inventory

A multi-layer, cartridge-based system that combines physical filtration with carbon adsorption and ultraviolet (UV) light disinfection has been developed to perform as a water treatment security device to protect homes against accidental or intentional contaminant events. A seri...

Dielectrophoresis-Assisted Integration of 1024 Carbon Nanotube Sensors into a CMOS Microsystem.

PubMed

Seichepine, Florent; Rothe, Jörg; Dudina, Alexandra; Hierlemann, Andreas; Frey, Urs

2017-05-01

Carbon-nanotube (CNT)-based sensors offer the potential to detect single-molecule events and picomolar analyte concentrations. An important step toward applications of such nanosensors is their integration in large arrays. The availability of large arrays would enable multiplexed and parallel sensing, and the simultaneously obtained sensor signals would facilitate statistical analysis. A reliable method to fabricate an array of 1024 CNT-based sensors on a fully processed complementary-metal-oxide-semiconductor microsystem is presented. A high-yield process for the deposition of CNTs from a suspension by means of liquid-coupled floating-electrode dielectrophoresis (DEP), which yielded 80% of the sensor devices featuring between one and five CNTs, is developed. The mechanism of floating-electrode DEP on full arrays and individual devices to understand its self-limiting behavior is studied. The resistance distributions across the array of CNT devices with respect to different DEP parameters are characterized. The CNT devices are then operated as liquid-gated CNT field-effect-transistors (LG-CNTFET) in liquid environment. Current dependency to the gate voltage of up to two orders of magnitude is recorded. Finally, the sensors are validated by studying the pH dependency of the LG-CNTFET conductance and it is demonstrated that 73% of the CNT sensors of a given microsystem show a resistance decrease upon increasing the pH value. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Chemical detection with nano/bio hybrid devices based on carbon nanotubes and graphene

NASA Astrophysics Data System (ADS)

Lerner, Mitchell Bryant

Carbon nanotube field-effect transistors (NT-FETs) and graphene field effect transistors (GFETs) provide a unique transduction platform for chemical and biomolecular detection. The work presented in this thesis describes the fabrication, characterization, and investigation of operational mechanisms of carbon-based biosensors. In the first set of experiments, we used carbon nanotubes as fast, all-electronic readout elements in novel vapor sensors, suitable for applications in environmental monitoring and medicine. Molecules bound to the hybrid alter the electrical properties of the NT-FET via several mechanisms, allowing direct detection as a change in the transistor conduction properties. Vapor sensors suitable for more complex system architectures characteristic of mammalian olfaction were demonstrated using NT-FETs functionalized with mouse olfactory receptor (mOR) proteins or single stranded DNA (ssDNA). Substitution of graphene as the channel material enabled production of hundreds of electronically similar devices with high yield. Etching large scale chemical vapor deposition (CVD)-grown graphene into small channels is itself a challenging problem, and we have developed novel fabrication methods to this end without sacrificing the inherent electrical quality that makes graphene such an attractive material. Large arrays of such devices have potential utility for understanding the physics of ligand-receptor interactions and contributing to the development of a new generation of devices for electronic olfaction. Tailored and specific detection was accomplished by chemically functionalizing the NT-FET or GFET with biomolecules, such as proteins or small molecules, to create a hybrid nanostructures. Targets for detection were widely varied, indicating the utility of these techniques, such as 1) live Salmonella cells in nutrient broth, 2) a biomarker protein indicative of prostate cancer, 3) antigen protein from the bacterium that causes Lyme disease, and 4) glucose for diabetes monitoring. Further, we explored the potential of graphene as a readout element in similar transistor-based biosensors. We functionalized clean graphene devices with Histidine-tagged fluorescent proteins (FPs), producing a protein-graphene photodetector with wavelength selectivity based on the absorption spectrum of the FP. The work represents significant progress towards a general method for the tailored and specific detection of trace biological compounds using electronic readout for biomedical applications. We also investigated the fundamental operational mechanisms behind such nanotube-based sensors with a set of pyrene compounds that alter the local electrostatic environment in a predictable manner. While this experiment makes possible tuning of nanotube transistor properties, more generally these results could inform the development of quantitative models for the response of nanotube- and graphene-based biochemical sensors. Generic protein attachment chemistry combined with biochemists' ability to express proteins with high affinity for a particular target makes this research a platform technology capable of detecting any target with excellent sensitivity. Conceptually, this opens up a very large domain of intra- and intercellular communication to electronic eaves-dropping and could serve as a powerful tool for molecular and cell biology research.

Automatic Carbon Dioxide-Methane Gas Sensor Based on the Solubility of Gases in Water

PubMed Central

Cadena-Pereda, Raúl O.; Rivera-Muñoz, Eric M.; Herrera-Ruiz, Gilberto; Gomez-Melendez, Domingo J.; Anaya-Rivera, Ely K.

2012-01-01

Biogas methane content is a relevant variable in anaerobic digestion processing where knowledge of process kinetics or an early indicator of digester failure is needed. The contribution of this work is the development of a novel, simple and low cost automatic carbon dioxide-methane gas sensor based on the solubility of gases in water as the precursor of a sensor for biogas quality monitoring. The device described in this work was used for determining the composition of binary mixtures, such as carbon dioxide-methane, in the range of 0–100%. The design and implementation of a digital signal processor and control system into a low-cost Field Programmable Gate Array (FPGA) platform has permitted the successful application of data acquisition, data distribution and digital data processing, making the construction of a standalone carbon dioxide-methane gas sensor possible. PMID:23112626

Strain-induced bi-thermoelectricity in tapered carbon nanotubes

NASA Astrophysics Data System (ADS)

Algharagholy, L. A. A.; Pope, T.; Lambert, C. J.

2018-03-01

We show that carbon-based nanostructured materials are a novel testbed for controlling thermoelectricity and have the potential to underpin the development of new cost-effective environmentally-friendly thermoelectric materials. In single-molecule junctions, it is known that transport resonances associated with the discrete molecular levels play a key role in the thermoelectric performance, but such resonances have not been exploited in carbon nanotubes (CNTs). Here we study junctions formed from tapered CNTs and demonstrate that such structures possess transport resonances near the Fermi level, whose energetic location can be varied by applying strain, resulting in an ability to tune the sign of their Seebeck coefficient. These results reveal that tapered CNTs form a new class of bi-thermoelectric materials, exhibiting both positive and negative thermopower. This ability to change the sign of the Seebeck coefficient allows the thermovoltage in carbon-based thermoelectric devices to be boosted by placing CNTs with alternating-sign Seebeck coefficients in tandem.

Automatic carbon dioxide-methane gas sensor based on the solubility of gases in water.

PubMed

Cadena-Pereda, Raúl O; Rivera-Muñoz, Eric M; Herrera-Ruiz, Gilberto; Gomez-Melendez, Domingo J; Anaya-Rivera, Ely K

2012-01-01

Biogas methane content is a relevant variable in anaerobic digestion processing where knowledge of process kinetics or an early indicator of digester failure is needed. The contribution of this work is the development of a novel, simple and low cost automatic carbon dioxide-methane gas sensor based on the solubility of gases in water as the precursor of a sensor for biogas quality monitoring. The device described in this work was used for determining the composition of binary mixtures, such as carbon dioxide-methane, in the range of 0-100%. The design and implementation of a digital signal processor and control system into a low-cost Field Programmable Gate Array (FPGA) platform has permitted the successful application of data acquisition, data distribution and digital data processing, making the construction of a standalone carbon dioxide-methane gas sensor possible.

Chemical control of electrical contact to sp² carbon atoms.

PubMed

Frederiksen, Thomas; Foti, Giuseppe; Scheurer, Fabrice; Speisser, Virginie; Schull, Guillaume

2014-04-16

Carbon-based nanostructures are attracting tremendous interest as components in ultrafast electronics and optoelectronics. The electrical interfaces to these structures play a crucial role for the electron transport, but the lack of control at the atomic scale can hamper device functionality and integration into operating circuitry. Here we study a prototype carbon-based molecular junction consisting of a single C60 molecule and probe how the electric current through the junction depends on the chemical nature of the foremost electrode atom in contact with the molecule. We find that the efficiency of charge injection to a C60 molecule varies substantially for the considered metallic species, and demonstrate that the relative strength of the metal-C bond can be extracted from our transport measurements. Our study further suggests that a single-C60 junction is a basic model to explore the properties of electrical contacts to meso- and macroscopic sp(2) carbon structures.

Chemical control of electrical contact to sp2 carbon atoms

NASA Astrophysics Data System (ADS)

Frederiksen, Thomas; Foti, Giuseppe; Scheurer, Fabrice; Speisser, Virginie; Schull, Guillaume

2014-04-01

Carbon-based nanostructures are attracting tremendous interest as components in ultrafast electronics and optoelectronics. The electrical interfaces to these structures play a crucial role for the electron transport, but the lack of control at the atomic scale can hamper device functionality and integration into operating circuitry. Here we study a prototype carbon-based molecular junction consisting of a single C60 molecule and probe how the electric current through the junction depends on the chemical nature of the foremost electrode atom in contact with the molecule. We find that the efficiency of charge injection to a C60 molecule varies substantially for the considered metallic species, and demonstrate that the relative strength of the metal-C bond can be extracted from our transport measurements. Our study further suggests that a single-C60 junction is a basic model to explore the properties of electrical contacts to meso- and macroscopic sp2 carbon structures.

Method of depositing multi-layer carbon-based coatings for field emission

DOEpatents

Sullivan, John P.; Friedmann, Thomas A.

1999-01-01

A novel field emitter device for cold cathode field emission applications, comprising a multi-layer resistive carbon film. The multi-layered film of the present invention is comprised of at least two layers of a resistive carbon material, preferably amorphous-tetrahedrally coordinated carbon, such that the resistivities of adjacent layers differ. For electron emission from the surface, the preferred structure comprises a top layer having a lower resistivity than the bottom layer. For edge emitting structures, the preferred structure of the film comprises a plurality of carbon layers, wherein adjacent layers have different resistivities. Through selection of deposition conditions, including the energy of the depositing carbon species, the presence or absence of certain elements such as H, N, inert gases or boron, carbon layers having desired resistivities can be produced. Field emitters made according the present invention display improved electron emission characteristics in comparison to conventional field emitter materials.

Method of depositing multi-layer carbon-based coatings for field emission

DOEpatents

Sullivan, J.P.; Friedmann, T.A.

1999-08-10

A novel field emitter device is disclosed for cold cathode field emission applications, comprising a multi-layer resistive carbon film. The multi-layered film of the present invention is comprised of at least two layers of a resistive carbon material, preferably amorphous-tetrahedrally coordinated carbon, such that the resistivities of adjacent layers differ. For electron emission from the surface, the preferred structure comprises a top layer having a lower resistivity than the bottom layer. For edge emitting structures, the preferred structure of the film comprises a plurality of carbon layers, wherein adjacent layers have different resistivities. Through selection of deposition conditions, including the energy of the depositing carbon species, the presence or absence of certain elements such as H, N, inert gases or boron, carbon layers having desired resistivities can be produced. Field emitters made according the present invention display improved electron emission characteristics in comparison to conventional field emitter materials. 8 figs.

Semiconductor-Based Photoelectrochemical Conversion of Carbon Dioxide: Stepping Towards Artificial Photosynthesis.

PubMed

Pang, Hong; Masuda, Takuya; Ye, Jinhua

2018-01-18

The photoelectrochemical (PEC) carbon dioxide reduction process stands out as a promising avenue for the conversion of solar energy into chemical feedstocks, among various methods available for carbon dioxide mitigation. Semiconductors derived from cheap and abundant elements are interesting candidates for catalysis. Whether employed as intrinsic semiconductors or hybridized with metallic cocatalysts, biocatalysts, and metal molecular complexes, semiconductor photocathodes exhibit good performance and low overpotential during carbon dioxide reduction. Apart from focusing on carbon dioxide reduction materials and chemistry, PEC cells towards standalone devices that use photohybrid electrodes or solar cells have also been a hot topic in recent research. An overview of the state-of-the-art progress in PEC carbon dioxide reduction is presented and a deep understanding of the catalysts of carbon dioxide reduction is also given. © 2018 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

Reconfigurable Carbon Nanotube Multiplexed Sensing Devices.

PubMed

Xu, Xinzhao; Clément, Pierrick; Eklöf-Österberg, Johnas; Kelley-Loughnane, Nancy; Moth-Poulsen, Kasper; Chávez, Jorge L; Palma, Matteo

2018-06-26

Here we report on the fabrication of reconfigurable and solution processable nanoscale biosensors with multisensing capability, based on single-walled carbon nanotubes (SWCNTs). Distinct DNA-wrapped (hence water-soluble) CNTs were immobilized from solution onto different prepatterned electrodes on the same chip, via a low-cost dielectrophoresis (DEP) methodology. The CNTs were functionalized with specific, and different, aptamer sequences that were employed as selective recognition elements for biomarkers indicative of stress and neuro-trauma conditions. Multiplexed detection of three different biomarkers was successfully performed, and real-time detection was achieved in serum down to physiologically relevant concentrations of 50 nM, 10 nM, and 500 pM for cortisol, dehydroepiandrosterone-sulfate (DHEAS), and neuropeptide Y (NPY), respectively. Additionally, the fabricated nanoscale devices were shown to be reconfigurable and reusable via a simple cleaning procedure. The general applicability of the strategy presented, and the facile device fabrication from aqueous solution, hold great potential for the development of the next generation of low power consumption portable diagnostic assays for the simultaneous monitoring of different health parameters.

Nanocarbon-Based Materials for Flexible All-Solid-State Supercapacitors.

PubMed

Lv, Tian; Liu, Mingxian; Zhu, Dazhang; Gan, Lihua; Chen, Tao

2018-04-01

Because of the rapid development of flexible electronics, it is important to develop high-performance flexible energy-storage devices, such as supercapacitors and metal-ion batteries. Compared with metal-ion batteries, supercapacitors exhibit higher power density, longer cycling life, and excellent safety, and they can be easily fabricated into all-solid-state devices by using polymer gel electrolytes. All-solid-state supercapacitors (ASSSCs) have the advantages of being lightweight and flexible, thus showing great potential to be used as power sources for flexible portable electronics. Because of their high specific surface area and excellent electrical and mechanical properties, nanocarbon materials (such as carbon nanotubes, graphene, carbon nanofibers, and so on) have been widely used as efficient electrode materials for flexible ASSSCs, and great achievements have been obtained. Here, the recent advances in flexible ASSSCs are summarized, from design strategies to fabrication techniques for nanocarbon electrodes and devices. Current challenges and future perspectives are also discussed. © 2018 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

An ultra-broadband perovskite-PbS quantum dot sensitized carbon nanotube photodetector.

PubMed

Ka, Ibrahima; Gerlein, Luis F; Asuo, Ivy M; Nechache, Riad; Cloutier, Sylvain G

2018-05-17

Organic-inorganic perovskites have been hailed as promising candidates for optoelectronic and photovoltaic devices, but their operation remains limited to the visible spectrum. Here, we combine single-wall carbon nanotubes, PbS quantum dots and a perovskite to synthesize hybrid devices suitable for operation in both the visible and near-infrared. The photodetectors thus fabricated show responsivities as high as 0.5 A W-1 and 0.35 A W-1 at 500 nm and at 1300 nm, respectively, with an applied bias of 1 V. Moreover, the incorporation of nanotubes within the perovskite matrix facilitates the carrier extraction, resulting in response time under 250 μs, a gain-bandwidth product of 0.1 MHz and detectivities of 1.4 × 1011 Jones and 0.9 × 1011 Jones at 500 nm and at 1300 nm, respectively. This unique approach opens new pathways for the development of low-cost, high-speed and broadband perovskite-based optoelectronic devices for large-scale manufacturing.

Electric double-layer capacitors based on highly graphitized nanoporous carbons derived from ZIF-67.

PubMed

Torad, Nagy L; Salunkhe, Rahul R; Li, Yunqi; Hamoudi, Hicham; Imura, Masataka; Sakka, Yoshio; Hu, Chi-Chang; Yamauchi, Yusuke

2014-06-23

Nanoporous carbons (NPCs) have large specific surface areas, good electrical and thermal conductivity, and both chemical and mechanical stability, which facilitate their use in energy storage device applications. In the present study, highly graphitized NPCs are synthesized by one-step direct carbonization of cobalt-containing zeolitic imidazolate framework-67 (ZIF-67). After chemical etching, the deposited Co content can be completely removed to prepare pure NPCs with high specific surface area, large pore volume, and intrinsic electrical conductivity (high content of sp(2) -bonded carbons). A detailed electrochemical study is performed using cyclic voltammetry and galvanostatic charge-discharge measurements. Our NPC is very promising for efficient electrodes for high-performance supercapacitor applications. A maximum specific capacitance of 238 F g(-1) is observed at a scan rate of 20 mV s(-1) . This value is very high compared to previous works on carbon-based electric double layer capacitors. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Characterizing Graphene-modified Electrodes for Interfacing with Arduino®-based Devices.

PubMed

Arris, Farrah Aida; Ithnin, Mohamad Hafiz; Salim, Wan Wardatul Amani Wan

2016-08-01

Portable low-cost platform and sensing systems for identification and quantitative measurement are in high demand for various environmental monitoring applications, especially in field work. Quantifying parameters in the field requires both minimal sample handling and a device capable of performing measurements with high sensitivity and stability. Furthermore, the one-device-fits-all concept is useful for continuous monitoring of multiple parameters. Miniaturization of devices can be achieved by introducing graphene as part of the transducer in an electrochemical sensor. In this project, we characterize graphene deposition methods on glassy-carbon electrodes (GCEs) with the goal of interfacing with an Arduino-based user-friendly microcontroller. We found that a galvanostatic electrochemical method yields the highest peak current of 10 mA, promising a highly sensitive electrochemical sensor. An Atlas Scientific™ printed circuit board (PCB) was connected to an Arduino® microcontroller using a multi-circuit connection that can be interfaced with graphene-based electrochemical sensors for environmental monitoring.

Construction and electrochemical characterization of microelectrodes for improved sensitivity in paper-based analytical devices

PubMed Central

Santhiago, Murilo; Wydallis, John B.; Kubota, Lauro T.; Henry, Charles S.

2013-01-01

This work presents a simple, low cost method for creating microelectrodes for electrochemical paper-based analytical devices (ePADs). The microelectrodes were constructed by backfilling small holes made in polyester sheets using a CO2 laser etching system. To make electrical connections, the working electrodes were combined with silver screen-printed paper in a sandwich type two-electrode configuration. The devices were characterized using linear sweep voltammetry and the results are in good agreement with theoretical predictions for electrode size and shape. As a proof-of-concept, cysteine was measured using cobalt phthalocyanine as a redox mediator. The rate constant (kobs) for the chemical reaction between cysteine and the redox mediator was obtained by chronoamperometry and found to be on the order of 105 s−1 M−1. Using a microelectrode array, it was possible to reach a limit of detection of 4.8 μM for cysteine. The results show that carbon paste microelectrodes can be easily integrated with paper-based analytical devices. PMID:23581428

Construction and electrochemical characterization of microelectrodes for improved sensitivity in paper-based analytical devices.

PubMed

Santhiago, Murilo; Wydallis, John B; Kubota, Lauro T; Henry, Charles S

2013-05-21

This work presents a simple, low cost method for creating microelectrodes for electrochemical paper-based analytical devices (ePADs). The microelectrodes were constructed by backfilling small holes made in polyester sheets using a CO2 laser etching system. To make electrical connections, the working electrodes were combined with silver screen-printed paper in a sandwich type two-electrode configuration. The devices were characterized using linear sweep voltammetry, and the results are in good agreement with theoretical predictions for electrode size and shape. As a proof-of-concept, cysteine was measured using cobalt phthalocyanine as a redox mediator. The rate constant (k(obs)) for the chemical reaction between cysteine and the redox mediator was obtained by chronoamperometry and found to be on the order of 10(5) s(-1) M(-1). Using a microelectrode array, it was possible to reach a limit of detection of 4.8 μM for cysteine. The results show that carbon paste microelectrodes can be easily integrated with paper-based analytical devices.

Nanoscale adhesion interactions in carbon nanotube based systems and experimental study of the mechanical properties of carbon and boron nitride nanotubes

NASA Astrophysics Data System (ADS)

Zheng, Meng

Part I: Carbon nanotubes (CNTs) are a type of 1D nanostructures, which possess extraordinary mechanical, electrical, thermal, and chemical properties and are promising for a number of applications. For many of their applications, CNTs will be assembled into micro or macro-scale structures (e.g. thin-films and yarns), or integrated with other bulk materials to form heterogeneous material systems and devices (e.g. nanocomposites and solid-state electronics). The interfaces formed among CNTs themselves and between the CNT and other material surfaces play crucial roles in the functioning and performance of CNT-based material systems and devices. Therefore, characterization of the interfacial interaction in CNT-based systems is a critical step to understand the nanoscale interface and tune the system and device design and manufacturing for optimal functioning and performance. In this part of dissertation, a combination of both mechanical and theoretical methods was employed to study the adhesion interactions in CNT-based systems. Part II: Both CNTs and boron nitride nanotubes (BNNTs) possess superb mechanical properties and are promising for a great many applications. They can be used in similar applications, such as reinforcing fibers in polymer composites based on their similar mechanical and thermal properties. CNTs are promising for electronics and sensors while BNNTs can be used as electrical insulators due to the tremendous differences of the electrical property. Furthermore, BNNTs can survive in high temperature and hazardous environments because of their resistant to oxidation and harsh chemicals. In order to optimize their applications, their mechanical properties should be fully understood. In this part of the dissertation research, first, the radial elasticity of single-walled CNTs and BNNTs was investigated by means of atomic force microscopy (AFM); secondly, the engineering radial deformations in single walled CNTs and BNNTs covered by monolayer grapheme oxide (GO) is presented.

Metal-Phenolic Carbon Nanocomposites for Robust and Flexible Energy-Storage Devices.

PubMed

Oh, Jun Young; Jung, Yeonsu; Cho, Young Shik; Choi, Jaeyoo; Youk, Ji Ho; Fechler, Nina; Yang, Seung Jae; Park, Chong Rae

2017-04-22

Future electronics applications such as wearable electronics depend on the successful construction of energy-storage devices with superior flexibility and high electrochemical performance. However, these prerequisites are challenging to combine: External forces often cause performance degradation, whereas the trade-off between the required nanostructures for strength and electrochemical performance only results in diminished energy storage. Herein, a flexible supercapacitor based on tannic acid (TA) and carbon nanotubes (CNTs) with a unique nanostructure is presented. TA was self-assembled on the surface of the CNTs by metal-phenolic coordination bonds, which provides the hybrid film with both high strength and high pseudocapacitance. Besides 17-fold increased mechanical strength of the final composite, the hybrid film simultaneously exhibits excellent flexibility and volumetric capacitance. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

Film Sensor Device Fabricated by a Piezoelectric Poly(L-lactic acid) Film

NASA Astrophysics Data System (ADS)

Ando, Masamichi; Kawamura, Hideki; Kageyama, Keisuke; Tajitsu, Yoshiro

2012-09-01

Synthetic piezoelectric polymer films produced from petroleum feedstock have long been used as thin-film sensors and actuators. However, the fossil fuel requirements for synthetic polymer production and carbon dioxide emission from its combustion have raised concern about the environmental impact of its continued use. Eco-friendly biomass polymers, such as poly(L-lactic acid) (PLLA), are made from plant-based (vegetable starch) plastics and, thus, have a much smaller carbon footprint. Additionally, PLLA does not exhibit pyroelectricity or unnecessary poling. This suggests the usefulness of PLLA films for the human-machine interface (HMI). As an example of a new HMI, we have produced a TV remote control using a PLLA film. The intuitive operation provided by this PLLA device suggests that it is useful for the elderly or handicapped.

Resolving Single Molecule Lysozyme Dynamics with a Carbon Nanotube Electronic Circuit

NASA Astrophysics Data System (ADS)

Choi, Yongki; Moody, Issa S.; Perez, Israel; Sheps, Tatyana; Weiss, Gregory A.; Collins, Philip G.

2011-03-01

High resolution, real-time monitoring of a single lysozyme molecule is demonstrated by fabricating nanoscale electronic devices based on single-walled carbon nanotubes (SWCNT). In this sensor platform, a biomolecule of interest is attached to a single SWCNT device. The electrical conductance transduces chemical events with single molecule sensitivity and 10 microsecond resolution. In this work, enzymatic turnover by lysozyme is investigated, because the mechanistic details for its processivity and dynamics remain incompletely understood. Stochastically distributed binding events between a lysozyme and its binding substrate, peptidoglycan, are monitored via the sensor conductance. Furthermore, the magnitude and repetition rate of these events varies with pH and the presence of inhibitors or denaturation agents. Changes in the conductance signal are analyzed in terms of lysozyme's internal hinge motion, binding events, and enzymatic processing.

Modulating the spin transport behaviors in ZBNCNRs by edge hydrogenation and position of BN chain

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ouyang, Jun; Long, Mengqiu, E-mail: mqlong@csu.edu.cn, E-mail: ygao@csu.edu.cn; Zhang, Dan

2016-03-15

Using the density functional theory and the nonequilibrium Green’s function method, we study the spin transport behaviors in zigzag boron-nitrogen-carbon nanoribbons (ZBNCNRs) by modulating the edge hydrogenation and the position of B-N nanoribbons (BNNRs) chain. The different edge hydrogenations of the ZBNCNRs and the different position relationships of the BNNRs have been considered systematically. Our results show that the metallic, semimetallic and semiconductive properties of the ZBNCNRs can be modulated by the different edge hydrogenations and different position relationships of BN chains. And our proposaled ZBNCNRs devices act as perfect spin-filters with nearly 100% spin polarization. These effects would havemore » potential applications for boron-nitrogen-carbon-based nanomaterials in spintronics nano-devices.« less

Gas Transfer in Cellularized Collagen-Membrane Gas Exchange Devices.

PubMed

Lo, Justin H; Bassett, Erik K; Penson, Elliot J N; Hoganson, David M; Vacanti, Joseph P

2015-08-01

Chronic lower respiratory disease is highly prevalent in the United States, and there remains a need for alternatives to lung transplant for patients who progress to end-stage lung disease. Portable or implantable gas oxygenators based on microfluidic technologies can address this need, provided they operate both efficiently and biocompatibly. Incorporating biomimetic materials into such devices can help replicate native gas exchange function and additionally support cellular components. In this work, we have developed microfluidic devices that enable blood gas exchange across ultra-thin collagen membranes (as thin as 2 μm). Endothelial, stromal, and parenchymal cells readily adhere to these membranes, and long-term culture with cellular components results in remodeling, reflected by reduced membrane thickness. Functionally, acellular collagen-membrane lung devices can mediate effective gas exchange up to ∼288 mL/min/m(2) of oxygen and ∼685 mL/min/m(2) of carbon dioxide, approaching the gas exchange efficiency noted in the native lung. Testing several configurations of lung devices to explore various physical parameters of the device design, we concluded that thinner membranes and longer gas exchange distances result in improved hemoglobin saturation and increases in pO2. However, in the design space tested, these effects are relatively small compared to the improvement in overall oxygen and carbon dioxide transfer by increasing the blood flow rate. Finally, devices cultured with endothelial and parenchymal cells achieved similar gas exchange rates compared with acellular devices. Biomimetic blood oxygenator design opens the possibility of creating portable or implantable microfluidic devices that achieve efficient gas transfer while also maintaining physiologic conditions.

A pH sensor based on electric properties of nanotubes on a glass substrate

PubMed Central

Nakamura, Motonori; Ishii, Atsushi; Subagyo, Agus; Hosoi, Hirotaka; Sueoka, Kazuhisa; Mukasa, Koichi

2007-01-01

We fabricated a pH-sensitive device on a glass substrate based on properties of carbon nanotubes. Nanotubes were immobilized specifically on chemically modified areas on a substrate followed by deposition of metallic source and drain electrodes on the area. Some nanotubes connected the source and drain electrodes. A top gate electrode was fabricated on an insulating layer of silane coupling agent on the nanotube. The device showed properties of ann-type field effect transistor when a potential was applied to the nanotube from the top gate electrode. Before fabrication of the insulating layer, the device showed that thep-type field effect transistor and the current through the source and drain electrodes depend on the buffer pH. The current increases with decreasing pH of the CNT solution. This device, which can detect pH, is applicable for use as a biosensor through modification of the CNT surface. PMID:21806848

Single-Step Reagentless Laser Scribing Fabrication of Electrochemical Paper-Based Analytical Devices.

PubMed

de Araujo, William R; Frasson, Carolina M R; Ameku, Wilson A; Silva, José R; Angnes, Lúcio; Paixão, Thiago R L C

2017-11-20

A single-step laser scribing process is used to pattern nanostructured electrodes on paper-based devices. The facile and low-cost technique eliminates the need for chemical reagents or controlled conditions. This process involves the use of a CO 2 laser to pyrolyze the surface of the paperboard, producing a conductive porous non-graphitizing carbon material composed of graphene sheets and composites with aluminosilicate nanoparticles. The new electrode material was extensively characterized, and it exhibits high conductivity and an enhanced active/geometric area ratio; it is thus well-suited for electrochemical purposes. As a proof-of-concept, the devices were successfully employed for different analytical applications in the clinical, pharmaceutical, food, and forensic fields. The scalable and green fabrication method associated with the features of the new material is highly promising for the development of portable electrochemical devices. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

Graphene and carbon nanotubes: synthesis, characterization and applications for beyond silicon electronics

NASA Astrophysics Data System (ADS)

Gomez de Arco, Lewis Mortimer

Graphene and carbon nanotubes have outstanding electrical and thermal conductivity. These characteristics make them exciting materials with high potential to replace silicon and surpass its performance in the next generation of semiconductors devices, such devices ought to be considerably smaller and faster than the ones used in present technology. Despite of the excellent electrical and thermal conduction properties of graphene and carbon nanotubes, the advance of nanoelectronics based on them has been hampered due to fundamental limitations of the current synthesis and integration technologies of these carbon nanomaterials. Therefore, there is a strong need to do research at fundamental and applicative levels to help find the roadmap that these materials need to follow, in order to become a real alternative for silicon in future technologies. This dissertation present our approach to overcome some of the most critical problems that hinder the implementation of graphene and carbon nanotubes as important components in real-life macro and nanoelectronic devices. Towards this end, we systematically studied synthesis methods for scalable, high quality graphene and evaluated our large-scale synthesized graphene as transparent electrodes in functional energy conversion devices. In addition, we explored scalable methods to obtain carbon nanotube field-effect transistors with only semiconductor nanotube channels and studied the substrate influence on the structure and metal to semiconductor ratio of aligned nanotubes. Although we have successfully tackled some of the most important challenges of the above-mentioned one- and two-dimensional carbon nanostructures, more remains to be done to integrate them as functional components in electronic devices to reach the goal of transferring them from the laboratory to the manufacturing industry, and ultimately to the society. In chapter 1, a general introduction to carbon nanomaterials is presented, followed by a more focused discussion on the structure and properties of graphene and carbon nanotubes. Chapter 2, presents the development of a chemical vapor deposition method for scalable graphene synthesis and the evaluation of its electrical properties as the active channel in field effect transistor and as a transparent conductor. Chapter 3 presents further work on graphene synthesis on single crystal nickel and the influence of the substrate atomic arrangement on the synthesized graphene. Chapter 4 presents the implementation of the highly scalable graphene synthesized by CVD as the transparent electrode in flexible organic photovoltaic cells. Chapter 5 evaluates the influence of substrate/nanotube interactions during align nanotube growth on the Raman signature of the resulting aligned nanotubes, nanotube structure and metal to semiconductor ratio. Chapter 6 presents our findings on a scalable method that can be used at wafer scale to achieve metal to semiconductor conversion of carbon nanotubes by light irradiation and its application to achieve semiconducting CNTFETs. Finally, in chapter 7, future research directions in related areas of science and technology are proposed.

3D direct writing fabrication of electrodes for electrochemical storage devices

NASA Astrophysics Data System (ADS)

Wei, Min; Zhang, Feng; Wang, Wei; Alexandridis, Paschalis; Zhou, Chi; Wu, Gang

2017-06-01

Among different printing techniques, direct ink writing is commonly used to fabricate 3D battery and supercapacitor electrodes. The major advantages of using the direct ink writing include effectively building 3D structure for energy storage devices and providing higher power density and higher energy density than traditional techniques due to the increased surface area of electrode. Nevertheless, direct ink writing has high standards for the printing inks, which requires high viscosity, high yield stress under shear and compression, and well-controlled viscoelasticity. Recently, a number of 3D-printed energy storage devices have been reported, and it is very important to understand the printing process and the ink preparation process for further material design and technology development. We discussed current progress of direct ink writing technologies by using various electrode materials including carbon nanotube-based material, graphene-based material, LTO (Li4Ti5O12), LFP (LiFePO4), LiMn1-xFexPO4, and Zn-based metallic oxide. Based on achieve electrochemical performance, these 3D-printed devices deliver performance comparable to the energy storage device fabricated using traditional methods still leaving large room for further improvement. Finally, perspectives are provided on the potential future direction of 3D printing for all solid-state electrochemical energy storage devices.

Design of a device to remove lunar dust from space suits for the proposed lunar base

NASA Technical Reports Server (NTRS)

Harrington, David; Havens, Jack; Hester, Daniel

1990-01-01

The National Aeronautics and Space Administration plans to begin construction of a lunar base soon after the turn of the century. During the Apollo missions, lunar dust proved to be a problem because the dust adhered to all exposed material surfaces. Since lunar dust will be a problem during the establishment and operation of this base, the need exists for a device to remove the dust from space suits before the astronauts enter clean environments. The physical properties of lunar dust were characterized and energy methods for removing the dust were identified. Eight alternate designs were developed to remove the dust. The final design uses a brush and gas jet to remove the dust. The brush bristles are made from Kevlar fibers and the gas jet uses pressurized carbon dioxide from a portable tank. A throttling valve allows variable gas flow. Also, the tank is insulated with Kapton and electrically heated to prevent condensation of the carbon dioxide when the tank is exposed to the cold (- 240 F) lunar night.

Carbon nanotube transistor based high-frequency electronics

NASA Astrophysics Data System (ADS)

Schroter, Michael

At the nanoscale carbon nanotubes (CNTs) have higher carrier mobility and carrier velocity than most incumbent semiconductors. Thus CNT based field-effect transistors (FETs) are being considered as strong candidates for replacing existing MOSFETs in digital applications. In addition, the predicted high intrinsic transit frequency and the more recent finding of ways to achieve highly linear transfer characteristics have inspired investigations on analog high-frequency (HF) applications. High linearity is extremely valuable for an energy efficient usage of the frequency spectrum, particularly in mobile communications. Compared to digital applications, the much more relaxed constraints for CNT placement and lithography combined with already achieved operating frequencies of at least 10 GHz for fabricated devices make an early entry in the low GHz HF market more feasible than in large-scale digital circuits. Such a market entry would be extremely beneficial for funding the development of production CNTFET based process technology. This talk will provide an overview on the present status and feasibility of HF CNTFET technology will be given from an engineering point of view, including device modeling, experimental results, and existing roadblocks.

Radiation-Hard Complementary Integrated Circuits Based on Semiconducting Single-Walled Carbon Nanotubes.

PubMed

McMorrow, Julian J; Cress, Cory D; Gaviria Rojas, William A; Geier, Michael L; Marks, Tobin J; Hersam, Mark C

2017-03-28

Increasingly complex demonstrations of integrated circuit elements based on semiconducting single-walled carbon nanotubes (SWCNTs) mark the maturation of this technology for use in next-generation electronics. In particular, organic materials have recently been leveraged as dopant and encapsulation layers to enable stable SWCNT-based rail-to-rail, low-power complementary metal-oxide-semiconductor (CMOS) logic circuits. To explore the limits of this technology in extreme environments, here we study total ionizing dose (TID) effects in enhancement-mode SWCNT-CMOS inverters that employ organic doping and encapsulation layers. Details of the evolution of the device transport properties are revealed by in situ and in operando measurements, identifying n-type transistors as the more TID-sensitive component of the CMOS system with over an order of magnitude larger degradation of the static power dissipation. To further improve device stability, radiation-hardening approaches are explored, resulting in the observation that SWNCT-CMOS circuits are TID-hard under dynamic bias operation. Overall, this work reveals conditions under which SWCNTs can be employed for radiation-hard integrated circuits, thus presenting significant potential for next-generation satellite and space applications.

Establishment of a biomimetic device based on tri-layer polymer actuators--propulsion fins.

PubMed

Alici, Gursel; Spinks, Geoffrey; Huynh, Nam N; Sarmadi, Laleh; Minato, Rick

2007-06-01

We propose to use bending type tri-layer polymer actuators as propulsion fins for a biomimetic device consisting of a rigid body, like a box fish having a carapace, and paired fins running through the rigid body, like a fish having pectoral fins. The fins or polymer bending actuators can be considered as individually controlled flexible membranes. Each fin is activated with sinusoidal inputs such that there is a phase lag between the movements of successive fins to create enough thrust force for propulsion. Eight fins with 0.125 aspect ratio have been used along both sides of the rigid body to move the device in the direction perpendicular to the longitudinal axis of the body. The designed device with the paired fins was successfully tested, moving in an organic solution consisting of solvent, propylene carbonate (PC), and electrolyte. The design procedure outlined in this study is offered as a guide to making functional devices based on polymer actuators and sensors.

Highly Stretchable Multifunctional Wearable Devices Based on Conductive Cotton and Wool Fabrics.

PubMed

Souri, Hamid; Bhattacharyya, Debes

2018-06-05

The demand for stretchable, flexible, and wearable multifunctional devices based on conductive nanomaterials is rapidly increasing considering their interesting applications including human motion detection, robotics, and human-machine interface. There still exists a great challenge to manufacture stretchable, flexible, and wearable devices through a scalable and cost-effective fabrication method. Herein, we report a simple method for the mass production of electrically conductive textiles, made of cotton and wool, by hybridization of graphene nanoplatelets and carbon black particles. Conductive textiles incorporated into a highly elastic elastomer are utilized as highly stretchable and wearable strain sensors and heaters. The electromechanical characterizations of our multifunctional devices establish their excellent performance as wearable strain sensors to monitor various human motions, such as finger, wrist, and knee joint movements, and to recognize sound with high durability. Furthermore, the electrothermal behavior of our devices shows their potential application as stretchable and wearable heaters working at a maximum temperature of 103 °C powered with 20 V.

Ultrafast electron transfer in all-carbon-based SWCNT-C60 donor-acceptor nanoensembles connected by poly(phenylene-ethynylene) spacers

NASA Astrophysics Data System (ADS)

Barrejón, Myriam; Gobeze, Habtom B.; Gómez-Escalonilla, María J.; Fierro, José Luis G.; Zhang, Minfang; Yudasaka, Masako; Iijima, Sumio; D'Souza, Francis; Langa, Fernando

2016-08-01

Building all-carbon based functional materials for light energy harvesting applications could be a solution to tackle and reduce environmental carbon output. However, development of such all-carbon based donor-acceptor hybrids and demonstration of photoinduced charge separation in such nanohybrids is a challenge since in these hybrids part of the carbon material should act as an electron donating or accepting photosensitizer while the second part should fulfil the role of an electron acceptor or donor. In the present work, we have successfully addressed this issue by synthesizing covalently linked all-carbon-based donor-acceptor nanoensembles using single-walled carbon nanotubes (SWCNTs) as the donor and C60 as the acceptor. The donor-acceptor entities in the nanoensembles were connected by phenylene-ethynylene spacer units to achieve better electronic communication and to vary the distance between the components. These novel SWCNT-C60 nanoensembles have been characterized by a number of techniques, including TGA, FT-IR, Raman, AFM, absorbance and electrochemical methods. The moderate number of fullerene addends present on the side-walls of the nanotubes largely preserved the electronic structure of the nanotubes. The thermodynamic feasibility of charge separation in these nanoensembles was established using spectral and electrochemical data. Finally, occurrence of ultrafast electron transfer from the excited nanotubes in these donor-acceptor nanohybrids has been established by femtosecond transient absorption studies, signifying their utility in building light energy harvesting devices.Building all-carbon based functional materials for light energy harvesting applications could be a solution to tackle and reduce environmental carbon output. However, development of such all-carbon based donor-acceptor hybrids and demonstration of photoinduced charge separation in such nanohybrids is a challenge since in these hybrids part of the carbon material should act as an electron donating or accepting photosensitizer while the second part should fulfil the role of an electron acceptor or donor. In the present work, we have successfully addressed this issue by synthesizing covalently linked all-carbon-based donor-acceptor nanoensembles using single-walled carbon nanotubes (SWCNTs) as the donor and C60 as the acceptor. The donor-acceptor entities in the nanoensembles were connected by phenylene-ethynylene spacer units to achieve better electronic communication and to vary the distance between the components. These novel SWCNT-C60 nanoensembles have been characterized by a number of techniques, including TGA, FT-IR, Raman, AFM, absorbance and electrochemical methods. The moderate number of fullerene addends present on the side-walls of the nanotubes largely preserved the electronic structure of the nanotubes. The thermodynamic feasibility of charge separation in these nanoensembles was established using spectral and electrochemical data. Finally, occurrence of ultrafast electron transfer from the excited nanotubes in these donor-acceptor nanohybrids has been established by femtosecond transient absorption studies, signifying their utility in building light energy harvesting devices. Electronic supplementary information (ESI) available: Synthesis, TGA, FTIR, AFM and XPS data, UV-vis and transient absorption spectra (Fig. S1-S15 and Tables S1 and S2). See DOI: 10.1039/c6nr02829b

Engineering highly organized and aligned single walled carbon nanotube networks for electronic device applications: Interconnects, chemical sensor, and optoelectronics

NASA Astrophysics Data System (ADS)

Kim, Young Lae

For 20 years, single walled carbon nanotubes (SWNTs) have been studied actively due to their unique one-dimensional nanostructure and superior electrical, thermal, and mechanical properties. For these reasons, they offer the potential to serve as building blocks for future electronic devices such as field effect transistors (FETs), electromechanical devices, and various sensors. In order to realize these applications, it is crucial to develop a simple, scalable, and reliable nanomanufacturing process that controllably places aligned SWNTs in desired locations, orientations, and dimensions. Also electronic properties (semiconducting/metallic) of SWNTs and their organized networks must be controlled for the desired performance of devices and systems. These fundamental challenges are significantly limiting the use of SWNTs for future electronic device applications. Here, we demonstrate a strategy to fabricate highly controlled micro/nanoscale SWNT network structures and present the related assembly mechanism to engineer the SWNT network topology and its electrical transport properties. A method designed to evaluate the electrical reliability of such nano- and microscale SWNT networks is also presented. Moreover, we develop and investigate a robust SWNT based multifunctional selective chemical sensor and a range of multifunctional optoelectronic switches, photo-transistors, optoelectronic logic gates and complex optoelectronic digital circuits.

Functionalized Graphitic Carbon Nitride for Metal-free, Flexible and Rewritable Nonvolatile Memory Device via Direct Laser-Writing

NASA Astrophysics Data System (ADS)

Zhao, Fei; Cheng, Huhu; Hu, Yue; Song, Long; Zhang, Zhipan; Jiang, Lan; Qu, Liangti

2014-07-01

Graphitic carbon nitride nanosheet (g-C3N4-NS) has layered structure similar with graphene nanosheet and presents unusual physicochemical properties due to the s-triazine fragments. But their electronic and electrochemical applications are limited by the relatively poor conductivity. The current work provides the first example that atomically thick g-C3N4-NSs are the ideal candidate as the active insulator layer with tunable conductivity for achieving the high performance memory devices with electrical bistability. Unlike in conventional memory diodes, the g-C3N4-NSs based devices combined with graphene layer electrodes are flexible, metal-free and low cost. The functionalized g-C3N4-NSs exhibit desirable dispersibility and dielectricity which support the all-solution fabrication and high performance of the memory diodes. Moreover, the flexible memory diodes are conveniently fabricated through the fast laser writing process on graphene oxide/g-C3N4-NSs/graphene oxide thin film. The obtained devices not only have the nonvolatile electrical bistability with great retention and endurance, but also show the rewritable memory effect with a reliable ON/OFF ratio of up to 105, which is the highest among all the metal-free flexible memory diodes reported so far, and even higher than those of metal-containing devices.

Improved thermoelectric power output from multilayered polyethylenimine doped carbon nanotube based organic composites

DOE Office of Scientific and Technical Information (OSTI.GOV)

Hewitt, Corey A.; Montgomery, David S.; Barbalace, Ryan L.

2014-05-14

By appropriately selecting the carbon nanotube type and n-type dopant for the conduction layers in a multilayered carbon nanotube composite, the total device thermoelectric power output can be increased significantly. The particular materials chosen in this study were raw single walled carbon nanotubes for the p-type layers and polyethylenimine doped single walled carbon nanotubes for the n-type layers. The combination of these two conduction layers leads to a single thermocouple Seebeck coefficient of 96 ± 4 μVK{sup −1}, which is 6.3 times higher than that previously reported. This improved Seebeck coefficient leads to a total power output of 14.7 nW permore » thermocouple at the maximum temperature difference of 50 K, which is 44 times the power output per thermocouple for the previously reported results. Ultimately, these thermoelectric power output improvements help to increase the potential use of these lightweight, flexible, and durable organic multilayered carbon nanotube based thermoelectric modules in low powered electronics applications, where waste heat is available.« less

Hysteresis in Carbon Nanotube Transistors: Measurement and Analysis of Trap Density, Energy Level, and Spatial Distribution.

PubMed

Park, Rebecca Sejung; Shulaker, Max Marcel; Hills, Gage; Suriyasena Liyanage, Luckshitha; Lee, Seunghyun; Tang, Alvin; Mitra, Subhasish; Wong, H-S Philip

2016-04-26

We present a measurement technique, which we call the Pulsed Time-Domain Measurement, for characterizing hysteresis in carbon nanotube field-effect transistors, and demonstrate its applicability for a broad range of 1D and 2D nanomaterials beyond carbon nanotubes. The Pulsed Time-Domain Measurement enables the quantification (density, energy level, and spatial distribution) of charged traps responsible for hysteresis. A physics-based model of the charge trapping process for a carbon nanotube field-effect transistor is presented and experimentally validated using the Pulsed Time-Domain Measurement. Leveraging this model, we discover a source of traps (surface traps) unique to devices with low-dimensional channels such as carbon nanotubes and nanowires (beyond interface traps which exist in today's silicon field-effect transistors). The different charge trapping mechanisms for interface traps and surface traps are studied based on their temperature dependencies. Through these advances, we are able to quantify the interface trap density for carbon nanotube field-effect transistors (∼3 × 10(13) cm(-2) eV(-1) near midgap), and compare this against a range of previously studied dielectric/semiconductor interfaces.

Influence of temperature and electrolyte on the performance of activated-carbon supercapacitors

NASA Astrophysics Data System (ADS)

Liu, Ping; Verbrugge, Mark; Soukiazian, Souren

For hybrid electric vehicle traction applications, energy storage devices with high power density and energy efficiency are required. A primary attribute of supercapacitors is that they retain their high power density and energy efficiency even at -30 °C, the lowest temperature at which unassisted starting must be provided to customers. More abuse-tolerant electrolytes are preferred to the high-conductivity acetonitrile-based systems commonly employed. Propylene carbonate based electrolytes are a promising alternative. In this work, we compare the electrochemical performance of two high-power density electrical double layer supercapacitors employing acetonitrile and propylene carbonate as solvents. From this study, we are able to elucidate phenomena that control the resistance of supercapacitor at lower temperatures, and quantify the difference in performance associated with the two electrolytes.

Smart materials: strain sensing and stress determination by means of nanotube sensing systems, composites, and devices

NASA Technical Reports Server (NTRS)

Kim, Jong Dae (Inventor); Nagarajaiah, Satish (Inventor); Barrera, Enrique V. (Inventor); Dharap, Prasad (Inventor); Zhiling, Li (Inventor)

2010-01-01

The present invention is directed toward devices comprising carbon nanotubes that are capable of detecting displacement, impact, stress, and/or strain in materials, methods of making such devices, methods for sensing/detecting/monitoring displacement, impact, stress, and/or strain via carbon nanotubes, and various applications for such methods and devices. The devices and methods of the present invention all rely on mechanically-induced electronic perturbations within the carbon nanotubes to detect and quantify such stress/strain. Such detection and quantification can rely on techniques which include, but are not limited to, electrical conductivity/conductance and/or resistivity/resistance detection/measurements, thermal conductivity detection/measurements, electroluminescence detection/measurements, photoluminescence detection/measurements, and combinations thereof. All such techniques rely on an understanding of how such properties change in response to mechanical stress and/or strain.

Carbon nanotube polymer composition and devices

DOEpatents

Liu, Gao [Oakland, CA; Johnson, Stephen [Richmond, CA; Kerr, John B [Oakland, CA; Minor, Andrew M [El Cerrito, CA; Mao, Samuel S [Castro Valley, CA

2011-06-14

A thin film device and compound having an anode, a cathode, and at least one light emitting layer between the anode and cathode, the at least one light emitting layer having at least one carbon nanotube and a conductive polymer.

Water surface assisted synthesis of large-scale carbon nanotube film for high-performance and stretchable supercapacitors.

PubMed

Yu, Minghao; Zhang, Yangfan; Zeng, Yinxiang; Balogun, Muhammad-Sadeeq; Mai, Kancheng; Zhang, Zishou; Lu, Xihong; Tong, Yexiang

2014-07-16

A kind of multiwalled carbon-nanotube (MWCNT)/polydimethylsiloxane (PDMS) film with excellent conductivity and mechanical properties is developed using a facile and large-scale water surface assisted synthesis method. The film can act as a conductive support for electrochemically active PANI nano fibers. A device based on these PANI/MWCNT/PDMS electrodes shows good and stable capacitive behavior, even under static and dynamic stretching conditions. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

High-performance two-ply yarn supercapacitors based on carbon nanotubes and polyaniline nanowire arrays.

PubMed

Wang, Kai; Meng, Qinghai; Zhang, Yajie; Wei, Zhixiang; Miao, Menghe

2013-03-13

Fine count two-ply yarn supercapacitors are constructed from carbon nanotube yarns and polyaniline nanowires. The thread-like supercapacitor possess excellent electrochemical capacity and are very strong and flexible. When being woven or knitted into wearable electronic devices, alone or in combination with conventional textile yarns, the two-ply yarn supercapacitors can be flexed and stretched repeatedly without significant loss of capacitance. Copyright © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Effect of distribution, interface property and density of hydrogel-embedded vertically aligned carbon nanotube arrays on the properties of a flexible solid state supercapacitor

NASA Astrophysics Data System (ADS)

Zhu, Qi; Yuan, Xietao; Zhu, Yihao; Ni, Jiangfeng; Zhang, Xiaohua; Yang, Zhaohui

2018-05-01

In this paper we fabricate a robust flexible solid-state supercapacitor (FSC) device by embedding a conductive poly(vinyl alcohol) hydrogel into aligned carbon nanotube (CNT) arrays. We carefully investigate the effect of distribution, interface properties and densification of CNTs in the gel matrix on the electrochemical properties of an FSC. The total electrochemical capacitance of the device is measured to be 227 mF cm‑3 with a maximum energy density of 0.02 mWh cm‑3, which is dramatically enhanced compared with a similar device composed of non-parallel CNTs. Additionally, controllable in situ electrochemical oxidation greatly improved the compatibility between the hydrophobic CNTs and the hydrophilic hydrogel, which decreased the resistance of the device and introduced extra pseudocapacitance. After such oxidation treatment the energy storage ability further doubled to 430 mF cm‑3 with a maximum energy density of 0.04 mWh cm‑3 . The FSCs based on densified CNT arrays exhibited a much higher volumetric capacitance of 1140 mF cm‑3 and a larger energy density of 0.1 mWh cm‑3, with a large power density of 14 mW cm‑3. All devices show excellent stability of capacitance after at least 10 000 charge–discharge cycles with a loss of less than 2%. These easy-to-assemble hybrid arrays thus potentially provide a new method for manufacturing wearable devices and implantable medical devices.

Effect of distribution, interface property and density of hydrogel-embedded vertically aligned carbon nanotube arrays on the properties of a flexible solid state supercapacitor.

PubMed

Zhu, Qi; Yuan, Xietao; Zhu, Yihao; Ni, Jiangfeng; Zhang, Xiaohua; Yang, Zhaohui

2018-05-11

In this paper we fabricate a robust flexible solid-state supercapacitor (FSC) device by embedding a conductive poly(vinyl alcohol) hydrogel into aligned carbon nanotube (CNT) arrays. We carefully investigate the effect of distribution, interface properties and densification of CNTs in the gel matrix on the electrochemical properties of an FSC. The total electrochemical capacitance of the device is measured to be 227 mF cm -3 with a maximum energy density of 0.02 mWh cm -3 , which is dramatically enhanced compared with a similar device composed of non-parallel CNTs. Additionally, controllable in situ electrochemical oxidation greatly improved the compatibility between the hydrophobic CNTs and the hydrophilic hydrogel, which decreased the resistance of the device and introduced extra pseudocapacitance. After such oxidation treatment the energy storage ability further doubled to 430 mF cm -3 with a maximum energy density of 0.04 mWh cm -3 . The FSCs based on densified CNT arrays exhibited a much higher volumetric capacitance of 1140 mF cm -3 and a larger energy density of 0.1 mWh cm -3 , with a large power density of 14 mW cm -3 . All devices show excellent stability of capacitance after at least 10 000 charge-discharge cycles with a loss of less than 2%. These easy-to-assemble hybrid arrays thus potentially provide a new method for manufacturing wearable devices and implantable medical devices.

Kondo effect and enhanced magnetic properties in gadolinium functionalized carbon nanotube supramolecular complex.

PubMed

Ncube, S; Coleman, C; Strydom, A; Flahaut, E; de Sousa, A; Bhattacharyya, S

2018-05-23

We report on the enhancement of magnetic properties of multiwalled carbon nanotubes (MWNTs) functionalized with a gadolinium based supramolecular complex. By employing a newly developed synthesis technique we find that the functionalization method of the nanocomposite enhances the strength of magnetic interaction leading to a large effective moment of 15.79 µ B and non-superparamagnetic behaviour unlike what has been previously reported. Saturating resistance at low temperatures is fitted with the numerical renormalization group formula verifying the Kondo effect for magnetic impurities on a metallic electron system. Magnetoresistance shows devices fabricated from aligned gadolinium functionalized MWNTs (Gd-Fctn-MWNTs) exhibit spin-valve switching behaviour of up to 8%. This study highlights the possibility of enhancing magnetic interactions in carbon systems through chemical modification, moreover we demonstrate the rich physics that might be useful for developing spin based quantum computing elements based on one-dimensional (1D) channels.

Color vision deficits and laser eyewear protection for soft tissue laser applications.

PubMed

Teichman, J M; Vassar, G J; Yates, J T; Angle, B N; Johnson, A J; Dirks, M S; Thompson, I M

1999-03-01

Laser safety considerations require urologists to wear laser eye protection. Laser eye protection devices block transmittance of specific light wavelengths and may distort color perception. We tested whether urologists risk color confusion when wearing laser eye protection devices for laser soft tissue applications. Subjects were tested with the Farnsworth-Munsell 100-Hue Test without (controls) and with laser eye protection devices for carbon dioxide, potassium titanyl phosphate (KTP), neodymium (Nd):YAG and holmium:YAG lasers. Color deficits were characterized by error scores, polar graphs, confusion angles, confusion index, scatter index and color axes. Laser eye protection device spectral transmittance was tested with spectrophotometry. Mean total error scores plus or minus standard deviation were 13+/-5 for controls, and 44+/-31 for carbon dioxide, 273+/-26 for KTP, 22+/-6 for Nd:YAG and 14+/-8 for holmium:YAG devices (p <0.001). The KTP laser eye protection polar graphs, and confusion and scatter indexes revealed moderate blue-yellow and red-green color confusion. Color axes indicated no significant deficits for controls, or carbon dioxide, Nd:YAG or holmium:YAG laser eye protection in any subject compared to blue-yellow color vision deficits in 8 of 8 tested with KTP laser eye protection (p <0.001). Spectrophotometry demonstrated that light was blocked with laser eye protection devices for carbon dioxide less than 380, holmium:YAG greater than 850, Nd:YAG less than 350 and greater than 950, and KTP less than 550 and greater than 750 nm. The laser eye protection device for KTP causes significant blue-yellow and red-green color confusion. Laser eye protection devices for carbon dioxide, holmium:YAG and Nd:YAG cause no significant color confusion compared to controls. The differences are explained by laser eye protection spectrophotometry characteristics and visual physiology.

Uncovering the Fundamental Nature of Tribological Interfaces: High Resolution Tribology and Spectroscopy of Ultrahard Nanostructured Diamond Films for MEMS and Beyond

DTIC Science & Technology

2007-12-31

Wisconsin-Madison) for 2? ol !> o "S \\ % M 31 Statement of Objectives The original objectives of the proposal were as follows: 1. Obtain high-quality...performed multiple PEEM experiments on wear tracks on carbon-based films and polysilicon micro-electro mechanical systems (MEMS) devices, a comprehensive... polysilicon MEMS device known as the "nanotractor", and studies of the structure and composition of UNCD, ta-C, and nanocrystalline diamond (NCD) films. They

Applications of one-dimensional structured nanomaterials as biosensors and transparent electronics

NASA Astrophysics Data System (ADS)

Ishikawa, Fumiaki

This dissertation presents applications of one-dimensional structured nanomaterials, carbon nanotubes and In2O3 nanowires, for biosensors and transparent electronics. Chapter 1 gives the motivation to study applications of one-dimensional structured nanomaterials, and also brief introduction to structure, synthesis, and electronic properties of carbon nanotubes and In2O3 nanowires. In Chapter 2, introduction and motivation of biosensors using nanotubes/nanowires is given, followed by an overview on important background knowledge and concepts in biosensing. In Chapter 3, application of carbon nanotube biosensors toward brown tide algae detection is presented. Our devices successfully detected a brown tide marker selectively with real-time response. In Chapter 4, we demonstrate that In2O3 nanowire biosensors coupled with an antibody mimic protein (Fibronectin, Fn) can be used to detect nucleocapsid (N) protein, a biomarker for severe acute respiratory syndrome (SARS), at concentrations to below the sub-nanomolar range. In Chapter 5, we develop an analytical method to calibrate nanowire biosensor responses that can suppress the device-to-device variation in sensing response significantly. In Chapter 6, we investigate the effect of nanotube density on the biosensor performance, and proved that it plays an important role through systematic studies. In Chapter 7, I propose a future direction of nanobiosensors research, and show preliminary results along the proposed direction. I first present a concept of an ideal bioassay system with a list of requirements for the system, and propose the strategy of multi-integration to establish a system based on nanobiosensors that satisfies all of the requirements. In Chapter 8, we demonstrate high performance fully transparent transistors based on transfer printed aligned carbon nanotubes on both rigid and flexible substrates. We achieved device mobility as high as 1,300 cm 2V-1s-1 on glass substrates, which is the highest among transparent transistors reported so far. We also demonstrated fully transparent PMOS inverters on flexible substrates, and also successfully controlled commercial GaN light--emitting diodes (LEDs) with light intensity modulation of 103. Lastly, a brief summary of this thesis is given in Chapter 9.

Characterization of electrospun lignin based carbon fibers

DOE Office of Scientific and Technical Information (OSTI.GOV)

Poursorkhabi, Vida; Mohanty, Amar; Misra, Manjusri

2015-05-22

The production of lignin fibers has been studied in order to replace the need for petroleum based precursors for carbon fiber production. In addition to its positive environmental effects, it also benefits the economics of the industries which cannot take advantage of carbon fiber properties because of their high price. A large amount of lignin is annually produced as the byproduct of paper and growing cellulosic ethanol industry. Therefore, finding high value applications for this low cost, highly available material is getting more attention. Lignin is a biopolymer making about 15 – 30 % of the plant cell walls andmore » has a high carbon yield upon carbonization. However, its processing is challenging due to its low molecular weight and also variations based on its origin and the method of separation from cellulose. In this study, alkali solutions of organosolv lignin with less than 1 wt/v% of poly (ethylene oxide) and two types of lignin (hardwood and softwood) were electrospun followed by carbonization. Different heating programs for carbonization were tested. The carbonized fibers had a smooth surface with an average diameter of less than 5 µm and the diameter could be controlled by the carbonization process and lignin type. Scanning electron microscopy (SEM) was used to study morphology of the fibers before and after carbonization. Thermal conductivity of a sample with amorphous carbon was 2.31 W/m.K. The electrospun lignin carbon fibers potentially have a large range of application such as in energy storage devices and water or gas purification systems.« less

A fully roll-to-roll gravure-printed carbon nanotube-based active matrix for multi-touch sensors

PubMed Central

Lee, Wookyu; Koo, Hyunmo; Sun, Junfeng; Noh, Jinsoo; Kwon, Kye-Si; Yeom, Chiseon; Choi, Younchang; Chen, Kevin; Javey, Ali; Cho, Gyoujin

2015-01-01

Roll-to-roll (R2R) printing has been pursued as a commercially viable high-throughput technology to manufacture flexible, disposable, and inexpensive printed electronic devices. However, in recent years, pessimism has prevailed because of the barriers faced when attempting to fabricate and integrate thin film transistors (TFTs) using an R2R printing method. In this paper, we report 20 × 20 active matrices (AMs) based on single-walled carbon nanotubes (SWCNTs) with a resolution of 9.3 points per inch (ppi) resolution, obtained using a fully R2R gravure printing process. By using SWCNTs as the semiconducting layer and poly(ethylene terephthalate) (PET) as the substrate, we have obtained a device yield above 98%, and extracted the key scalability factors required for a feasible R2R gravure manufacturing process. Multi-touch sensor arrays were achieved by laminating a pressure sensitive rubber onto the SWCNT-TFT AM. This R2R gravure printing system overcomes the barriers associated with the registration accuracy of printing each layer and the variation of the threshold voltage (Vth). By overcoming these barriers, the R2R gravure printing method can be viable as an advanced manufacturing technology, thus enabling the high-throughput production of flexible, disposable, and human-interactive cutting-edge electronic devices based on SWCNT-TFT AMs. PMID:26635237

Single-Walled Carbon Nanotubes Probed with Insulator-Based Dielectrophoresis

PubMed Central

2017-01-01

Single-walled carbon nanotubes (SWNTs) offer unique electrical and optical properties. Common synthesis processes yield SWNTs with large length polydispersity (several tens of nanometers up to centimeters) and heterogeneous electrical and optical properties. Applications often require suitable selection and purification. Dielectrophoresis is one manipulation method for separating SWNTs based on dielectric properties and geometry. Here, we present a study of surfactant and single-stranded DNA-wrapped SWNTs suspended in aqueous solutions manipulated by insulator-based dielectrophoresis (iDEP). This method allows us to manipulate SWNTs with the help of arrays of insulating posts in a microfluidic device around which electric field gradients are created by the application of an electric potential to the extremities of the device. Semiconducting SWNTs were imaged during dielectrophoretic manipulation with fluorescence microscopy making use of their fluorescence emission in the near IR. We demonstrate SWNT trapping at low-frequency alternating current (AC) electric fields with applied potentials not exceeding 1000 V. Interestingly, suspended SWNTs showed both positive and negative dielectrophoresis, which we attribute to their ζ potential and the suspension properties. Such behavior agrees with common theoretical models for nanoparticle dielectrophoresis. We further show that the measured ζ potentials and suspension properties are in excellent agreement with a numerical model predicting the trapping locations in the iDEP device. This study is fundamental for the future application of low-frequency AC iDEP for technological applications of SWNTs. PMID:29131586

Recent Progress on Cellulose-Based Electro-Active Paper, Its Hybrid Nanocomposites and Applications

PubMed Central

Khan, Asif; Abas, Zafar; Kim, Heung Soo; Kim, Jaehwan

2016-01-01

We report on the recent progress and development of research into cellulose-based electro-active paper for bending actuators, bioelectronics devices, and electromechanical transducers. The cellulose electro-active paper is characterized in terms of its biodegradability, chirality, ample chemically modifying capacity, light weight, actuation capability, and ability to form hybrid nanocomposites. The mechanical, electrical, and chemical characterizations of the cellulose-based electro-active paper and its hybrid composites such as blends or coatings with synthetic polymers, biopolymers, carbon nanotubes, chitosan, and metal oxides, are explained. In addition, the integration of cellulose electro-active paper is highlighted to form various functional devices including but not limited to bending actuators, flexible speaker, strain sensors, energy harvesting transducers, biosensors, chemical sensors and transistors for electronic applications. The frontiers in cellulose paper devices are reviewed together with the strategies and perspectives of cellulose electro-active paper and cellulose nanocomposite research and applications. PMID:27472335

Fringing-field dielectrophoretic assembly of ultrahigh-density semiconducting nanotube arrays with a self-limited pitch

NASA Astrophysics Data System (ADS)

Cao, Qing; Han, Shu-Jen; Tulevski, George S.

2014-09-01

One key challenge of realizing practical high-performance electronic devices based on single-walled carbon nanotubes is to produce electronically pure nanotube arrays with both a minuscule and uniform inter-tube pitch for sufficient device-packing density and homogeneity. Here we develop a method in which the alternating voltage-fringing electric field formed between surface microelectrodes and the substrate is utilized to assemble semiconducting nanotubes into well-aligned, ultrahigh-density and submonolayered arrays, with a consistent pitch as small as 21±6 nm determined by a self-limiting mechanism, based on the unique field focusing and screening effects of the fringing field. Field-effect transistors based on such nanotube arrays exhibit record high device transconductance (>50 μS μm-1) and decent on current per nanotube (~1 μA per tube) together with high on/off ratios at a drain bias of -1 V.

Recent Progress on Cellulose-Based Electro-Active Paper, Its Hybrid Nanocomposites and Applications.

PubMed

Khan, Asif; Abas, Zafar; Kim, Heung Soo; Kim, Jaehwan

2016-07-26

We report on the recent progress and development of research into cellulose-based electro-active paper for bending actuators, bioelectronics devices, and electromechanical transducers. The cellulose electro-active paper is characterized in terms of its biodegradability, chirality, ample chemically modifying capacity, light weight, actuation capability, and ability to form hybrid nanocomposites. The mechanical, electrical, and chemical characterizations of the cellulose-based electro-active paper and its hybrid composites such as blends or coatings with synthetic polymers, biopolymers, carbon nanotubes, chitosan, and metal oxides, are explained. In addition, the integration of cellulose electro-active paper is highlighted to form various functional devices including but not limited to bending actuators, flexible speaker, strain sensors, energy harvesting transducers, biosensors, chemical sensors and transistors for electronic applications. The frontiers in cellulose paper devices are reviewed together with the strategies and perspectives of cellulose electro-active paper and cellulose nanocomposite research and applications.

Nanoelectronics from the bottom up.

PubMed

Lu, Wei; Lieber, Charles M

2007-11-01

Electronics obtained through the bottom-up approach of molecular-level control of material composition and structure may lead to devices and fabrication strategies not possible with top-down methods. This review presents a brief summary of bottom-up and hybrid bottom-up/top-down strategies for nanoelectronics with an emphasis on memories based on the crossbar motif. First, we will discuss representative electromechanical and resistance-change memory devices based on carbon nanotube and core-shell nanowire structures, respectively. These device structures show robust switching, promising performance metrics and the potential for terabit-scale density. Second, we will review architectures being developed for circuit-level integration, hybrid crossbar/CMOS circuits and array-based systems, including experimental demonstrations of key concepts such lithography-independent, chemically coded stochastic demultipluxers. Finally, bottom-up fabrication approaches, including the opportunity for assembly of three-dimensional, vertically integrated multifunctional circuits, will be critically discussed.

Biochips Containing Arrays of Carbon-Nanotube Electrodes

NASA Technical Reports Server (NTRS)

Li, Jun; Meyyappan, M.; Koehne, Jessica; Cassell, Alan; Chen, Hua

2008-01-01

Biochips containing arrays of nanoelectrodes based on multiwalled carbon nanotubes (MWCNTs) are being developed as means of ultrasensitive electrochemical detection of specific deoxyribonucleic acid (DNA) and messenger ribonucleic acid (mRNA) biomarkers for purposes of medical diagnosis and bioenvironmental monitoring. In mass production, these biochips could be relatively inexpensive (hence, disposable). These biochips would be integrated with computer-controlled microfluidic and microelectronic devices in automated hand-held and bench-top instruments that could be used to perform rapid in vitro genetic analyses with simplified preparation of samples. Carbon nanotubes are attractive for use as nanoelectrodes for detection of biomolecules because of their nanoscale dimensions and their chemical properties.

40 CFR 63.4965 - How do I determine the add-on control device emission destruction or removal efficiency?

Code of Federal Regulations, 2010 CFR

2010-07-01

... an alternative to Method 3B, the manual method for measuring the oxygen, carbon dioxide, and carbon..., Instruments and Apparatus]” (incorporated by reference, see § 63.14). (4) Use Method 4 of appendix A to 40 CFR... total gaseous organic mass emissions as carbon at the inlet and outlet of the add-on control device...

40 CFR 63.3545 - How do I determine the add-on control device emission destruction or removal efficiency?

Code of Federal Regulations, 2010 CFR

2010-07-01

... an alternative to Method 3B the manual method for measuring the oxygen, carbon dioxide, and carbon..., Instruments and Apparatus]” (incorporated by reference, see § 63.14). (4) Use Method 4 of appendix A to 40 CFR... total gaseous organic mass emissions as carbon at the inlet and outlet of the add-on control device...

Graphene-Composite Carbon Nanofiber-Based Electrodes for Energy Storage Devices

DTIC Science & Technology

2014-04-18

electrochemical supercapacitors . 1. Development of highly conductive graphene composite CNF webs Graphene, a single-atom-thick sheet of sp 2 bonded...electrochemical supercapacitors and evaluated their performance. The capacitance increased with an increase in the amount of MnO2 NWs (duration of the deposition

Functional carbon nitride materials — design strategies for electrochemical devices

NASA Astrophysics Data System (ADS)

Kessler, Fabian K.; Zheng, Yun; Schwarz, Dana; Merschjann, Christoph; Schnick, Wolfgang; Wang, Xinchen; Bojdys, Michael J.

2017-06-01

In the past decade, research in the field of artificial photosynthesis has shifted from simple, inorganic semiconductors to more abundant, polymeric materials. For example, polymeric carbon nitrides have emerged as promising materials for metal-free semiconductors and metal-free photocatalysts. Polymeric carbon nitride (melon) and related carbon nitride materials are desirable alternatives to industrially used catalysts because they are easily synthesized from abundant and inexpensive starting materials. Furthermore, these materials are chemically benign because they do not contain heavy metal ions, thereby facilitating handling and disposal. In this Review, we discuss the building blocks of carbon nitride materials and examine how strategies in synthesis, templating and post-processing translate from the molecular level to macroscopic properties, such as optical and electronic bandgap. Applications of carbon nitride materials in bulk heterojunctions, laser-patterned memory devices and energy storage devices indicate that photocatalytic overall water splitting on an industrial scale may be realized in the near future and reveal a new avenue of 'post-silicon electronics'.

Flexible and Binder-Free Hierarchical Porous Carbon Film for Supercapacitor Electrodes Derived from MOFs/CNT.

PubMed

Liu, Yazhi; Li, Gaoran; Guo, Yi; Ying, Yulong; Peng, Xinsheng

2017-04-26

Rational design of free-standing porous carbon materials with large specific surface area and high conductivity is a great need for ligh-weight suprecapacitors. Here, we report a flexible porous carbon film composed of metal-organic framework (MOF)-derived porous carbon polyhedrons and carbon nanotubes (CNTs) as binder-free supercapacitor electrode for the first time. Due to the synergistic combination of carbon polyhedrons and CNT, the obtained carbon electrode shows a specific capacitance of 381.2 F g -1 at 5 mV s -1 and 194.8 F g -1 at 2 A g -1 and outstanding cycling stability with a Coulombic effciency above 95% after 10000 cycles at 10 A g -1 . The assembled aqueous symmetrical supercapacitor exhibits an energy density of 9.1 Wh kg -1 with a power density of 3500 W kg -1 . The work opens a new way to design flexible MOF-based hierarchical porous carbon film as binder-free electrodes for high-performance energy storage devices.

Towards ultrahigh volumetric capacitance: graphene derived highly dense but porous carbons for supercapacitors

NASA Astrophysics Data System (ADS)

Tao, Ying; Xie, Xiaoying; Lv, Wei; Tang, Dai-Ming; Kong, Debin; Huang, Zhenghong; Nishihara, Hirotomo; Ishii, Takafumi; Li, Baohua; Golberg, Dmitri; Kang, Feiyu; Kyotani, Takashi; Yang, Quan-Hong

2013-10-01

A small volumetric capacitance resulting from a low packing density is one of the major limitations for novel nanocarbons finding real applications in commercial electrochemical energy storage devices. Here we report a carbon with a density of 1.58 g cm-3, 70% of the density of graphite, constructed of compactly interlinked graphene nanosheets, which is produced by an evaporation-induced drying of a graphene hydrogel. Such a carbon balances two seemingly incompatible characteristics: a porous microstructure and a high density, and therefore has a volumetric capacitance for electrochemical capacitors (ECs) up to 376 F cm-3, which is the highest value so far reported for carbon materials in an aqueous electrolyte. More promising, the carbon is conductive and moldable, and thus could be used directly as a well-shaped electrode sheet for the assembly of a supercapacitor device free of any additives, resulting in device-level high energy density ECs.

Towards ultrahigh volumetric capacitance: graphene derived highly dense but porous carbons for supercapacitors.

PubMed

Tao, Ying; Xie, Xiaoying; Lv, Wei; Tang, Dai-Ming; Kong, Debin; Huang, Zhenghong; Nishihara, Hirotomo; Ishii, Takafumi; Li, Baohua; Golberg, Dmitri; Kang, Feiyu; Kyotani, Takashi; Yang, Quan-Hong

2013-10-17

A small volumetric capacitance resulting from a low packing density is one of the major limitations for novel nanocarbons finding real applications in commercial electrochemical energy storage devices. Here we report a carbon with a density of 1.58 g cm(-3), 70% of the density of graphite, constructed of compactly interlinked graphene nanosheets, which is produced by an evaporation-induced drying of a graphene hydrogel. Such a carbon balances two seemingly incompatible characteristics: a porous microstructure and a high density, and therefore has a volumetric capacitance for electrochemical capacitors (ECs) up to 376 F cm(-3), which is the highest value so far reported for carbon materials in an aqueous electrolyte. More promising, the carbon is conductive and moldable, and thus could be used directly as a well-shaped electrode sheet for the assembly of a supercapacitor device free of any additives, resulting in device-level high energy density ECs.

Carbon composition with hierarchical porosity, and methods of preparation

DOEpatents

Mayes, Richard T; Dai, Sheng

2014-10-21

A method for fabricating a porous carbon material possessing a hierarchical porosity, the method comprising subjecting a precursor composition to a curing step followed by a carbonization step, the precursor composition comprising: (i) a templating component comprised of a block copolymer, (ii) a phenolic component, (iii) a dione component in which carbonyl groups are adjacent, and (iv) an acidic component, wherein said carbonization step comprises heating the precursor composition at a carbonizing temperature for sufficient time to convert the precursor composition to a carbon material possessing a hierarchical porosity comprised of mesopores and macropores. Also described are the resulting hierarchical porous carbon material, a capacitive deionization device in which the porous carbon material is incorporated, as well as methods for desalinating water by use of said capacitive deionization device.

Peptide aptamer-assisted immobilization of green fluorescent protein for creating biomolecule-complexed carbon nanotube device

NASA Astrophysics Data System (ADS)

Nii, Daisuke; Nozawa, Yosuke; Miyachi, Mariko; Yamanoi, Yoshinori; Nishihara, Hiroshi; Tomo, Tatsuya; Shimada, Yuichiro

2017-10-01

Carbon nanotubes are a novel material for next-generation applications. In this study, we generated carbon nanotube and green fluorescent protein (GFP) conjugates using affinity binding peptides. The carbon nanotube-binding motif was introduced into the N-terminus of the GFP through molecular biology methods. Multiple GFPs were successfully aligned on a single-walled carbon nanotube via the molecular recognition function of the peptide aptamer, which was confirmed through transmission electron microscopy and optical analysis. Fluorescence spectral analysis results also suggested that the carbon nanotube-GFP complex was autonomously formed with orientation and without causing protein denaturation during immobilization. This simple process has a widespread potential for fabricating carbon nanotube-biomolecule hybrid devices.

Simulation and parametric analysis of graphene p-n junctions with two rectangular top gates and a single back gate

NASA Astrophysics Data System (ADS)

Nikiforidis, Ioannis; Karafyllidis, Ioannis G.; Dimitrakis, Panagiotis

2018-02-01

Graphene p-n junctions could be the building blocks of future nanoelectronic circuits. While the conductance modulation of graphene p-n junctions formed in devices with one bottom and one top gate have received much attention, there is comparatively little work done on devices with two top gates. Here, we employ tight-bind Hamiltonians and non-equilibrium Green function method to compute in a systematic way the dependence of the conductance of graphene p-n junctions, formed in a device with two top gates, on the device parameters. We present our results in a compact and systematic way, so that the effect of each parameter is clearly shown. Our results show that the device conductance can be effectively modulated, and that graphene devices with two top gates may be used as basic elements in future carbon-based nanoelectronic circuits.

Fabrication of Glass Microchannel via Glass Imprinting using a Vitreous Carbon Stamp for Flow Focusing Droplet Generator

PubMed Central

Refatul Haq, Muhammad; Kim, Youngkyu; Kim, Jun; Oh, Pyoung-hwa; Ju, Jonghyun; Kim, Seok-Min; Lim, Jiseok

2017-01-01

This study reports a cost-effective method of replicating glass microfluidic chips using a vitreous carbon (VC) stamp. A glass replica with the required microfluidic microstructures was synthesized without etching. The replication method uses a VC stamp fabricated by combining thermal replication using a furan-based, thermally-curable polymer with carbonization. To test the feasibility of this method, a flow focusing droplet generator with flow-focusing and channel widths of 50 µm and 100 µm, respectively, was successfully fabricated in a soda-lime glass substrate. Deviation between the geometries of the initial shape and the vitreous carbon mold occurred because of shrinkage during the carbonization process, however this effect could be predicted and compensated for. Finally, the monodispersity of the droplets generated by the fabricated microfluidic device was evaluated. PMID:29286341

Fabrication Process of Silicone-based Dielectric Elastomer Actuators

PubMed Central

Rosset, Samuel; Araromi, Oluwaseun A.; Schlatter, Samuel; Shea, Herbert R.

2016-01-01

This contribution demonstrates the fabrication process of dielectric elastomer transducers (DETs). DETs are stretchable capacitors consisting of an elastomeric dielectric membrane sandwiched between two compliant electrodes. The large actuation strains of these transducers when used as actuators (over 300% area strain) and their soft and compliant nature has been exploited for a wide range of applications, including electrically tunable optics, haptic feedback devices, wave-energy harvesting, deformable cell-culture devices, compliant grippers, and propulsion of a bio-inspired fish-like airship. In most cases, DETs are made with a commercial proprietary acrylic elastomer and with hand-applied electrodes of carbon powder or carbon grease. This combination leads to non-reproducible and slow actuators exhibiting viscoelastic creep and a short lifetime. We present here a complete process flow for the reproducible fabrication of DETs based on thin elastomeric silicone films, including casting of thin silicone membranes, membrane release and prestretching, patterning of robust compliant electrodes, assembly and testing. The membranes are cast on flexible polyethylene terephthalate (PET) substrates coated with a water-soluble sacrificial layer for ease of release. The electrodes consist of carbon black particles dispersed into a silicone matrix and patterned using a stamping technique, which leads to precisely-defined compliant electrodes that present a high adhesion to the dielectric membrane on which they are applied. PMID:26863283

Nitrogen Gas Field Ion Source (GFIS) Focused Ion Beam (FIB) Secondary Electron Imaging: A First Look.

PubMed

Schmidt, Marek E; Yasaka, Anto; Akabori, Masashi; Mizuta, Hiroshi

2017-08-01

The recent technological advance of the gas field ion source (GFIS) and its successful integration into systems has renewed the interest in the focused ion beam (FIB) technology. Due to the atomically small source size and the use of light ions, the limitations of the liquid metal ion source are solved as device dimensions are pushed further towards the single-digit nanometer size. Helium and neon ions are the most widely used, but a large portfolio of available ion species is desirable, to allow a wide range of applications. Among argon and hydrogen, $${\\rm N}_{2}^{{\\plus}} $$ ions offer unique characteristics due to their covalent bond and their use as dopant for various carbon-based materials including diamond. Here, we provide a first look at the $${\\rm N}_{2}^{{\\plus}} $$ GFIS-FIB enabled imaging of a large selection of microscopic structures, including gold on carbon test specimen, thin metal films on insulator and nanostructured carbon-based devices, which are among the most actively researched materials in the field of nanoelectronics. The results are compared with images acquired by He+ ions, and we show that $${\\rm N}_{2}^{{\\plus}} $$ GFIS-FIB can offer improved material contrast even at very low imaging dose and is more sensitive to the surface roughness.

Length separation of single-walled carbon nanotubes and its impact on structural and electrical properties of wafer-level fabricated carbon nanotube-field-effect transistors

NASA Astrophysics Data System (ADS)

Böttger, Simon; Hermann, Sascha; Schulz, Stefan E.; Gessner, Thomas

2016-10-01

For an industrial realization of devices based on single-walled carbon nanotube (SWCNTs) such as field-effect transistors (FETs) it becomes increasingly important to consider technological aspects such as intrinsic device structure, integration process controllability as well as yield. From the perspective of a wafer-level integration technology, the influence of SWCNT length on the performance of short-channel CNT-FETs is demonstrated by means of a statistical and comparative study. Therefore, a methodological development of a length separation process based on size-exclusion chromatography was conducted in order to extract well-separated SWCNT dispersions with narrowed length distribution. It could be shown that short SWCNTs adversely affect integrability and reproducibility, underlined by a 25% decline of the integration yield with respect to long SWCNTs. Furthermore, it turns out that the significant changes in electrical performance are directly linked to a SWCNT chain formation in the transistor channel. In particular, CNT-FETs with long SWCNTs outperform reference and short SWCNTs with respect to hole mobility and subthreshold controllability by up to 300% and up to 140%, respectively. As a whole, this study provides a statistical and comparative analysis towards chain-less CNT-FETs fabricated with a wafer-level technology.

Semiconductor to metal transition by tuning the location of N{sub 2}{sup AA} in armchair graphene nanoribbons

DOE Office of Scientific and Technical Information (OSTI.GOV)

Chen, Tong; Wang, Ling-Ling, E-mail: llwang@hnu.edu.cn; Li, Quan

2014-02-07

The electronic band structures and transport properties of N{sub 2}{sup AA}-doped armchair graphene nanoribbons (aGNRs) with two quasi-adjacent substitutional nitrogen atoms incorporated in pairs of neighboring carbon atoms in the same sublattice A are investigated by using non-equilibrium Green function formalism in combination with density functional theory. The results show that the coupling effect between the Pz orbitals of carbon and nitrogen atoms plays an important role in the transition between semiconductor and metal by different locations of N{sub 2}{sup AA}-doped aGNRs. And the striking negative differential resistance behaviors can be found in such devices. These tremendous properties suggest potentialmore » application of N{sub 2}{sup AA}-doped aGNRs in graphene-based nanoelectronic devices.« less

Array of Chemosensitive Resistors with Composites of Gas Chromatography (GC) Materials and Carbon Black for Detection and Recognition of VOCs: A Basic Study

PubMed Central

Wyszynski, Bartosz; Yatabe, Rui; Nakao, Atsuo; Nakatani, Masaya; Oki, Akio; Oka, Hiroaki; Toko, Kiyoshi

2017-01-01

Mimicking the biological olfaction, large odor-sensor arrays can be used to acquire a broad range of chemical information, with a potentially high degree of redundancy, to allow for enhanced control over the sensitivity and selectivity of artificial olfaction systems. The arrays should consist of the largest possible number of individual sensing elements while being miniaturized. Chemosensitive resistors are one of the sensing platforms that have a potential to satisfy these two conditions. In this work we test viability of fabricating a 16-element chemosensitive resistor array for detection and recognition of volatile organic compounds (VOCs). The sensors were fabricated using blends of carbon black and gas chromatography (GC) stationary-phase materials preselected based on their sorption properties. Blends of the selected GC materials with carbon black particles were subsequently coated over chemosensitive resistor devices and the resulting sensors/arrays evaluated in exposure experiments against vapors of pyrrole, benzenal, nonanal, and 2-phenethylamine at 150, 300, 450, and 900 ppb. Responses of the fabricated 16-element array were stable and differed for each individual odorant sample, proving the blends of GC materials with carbon black particles can be effectively used for fabrication of large odor-sensing arrays based on chemosensitive resistors. The obtained results suggest that the proposed sensing devices could be effective in discriminating odor/vapor samples at the sub-ppm level. PMID:28696353

Nanocomposites based on hierarchical porous carbon fiber@vanadium nitride nanoparticles as supercapacitor electrodes.

PubMed

Ran, Fen; Wu, Yage; Jiang, Minghuan; Tan, Yongtao; Liu, Ying; Kong, Lingbin; Kang, Long; Chen, Shaowei

2018-03-28

In this study, a hybrid electrode material for supercapacitors based on hierarchical porous carbon fiber@vanadium nitride nanoparticles is fabricated using the method of phase-separation mediated by the PAA-b-PAN-b-PAA tri-block copolymer. In the phase-separation procedure, the ionic block copolymer self-assembled on the surface of carbon nanofibers, and is used to adsorb NH 4 VO 3 . Thermal treatment at controlled temperatures under an NH 3  : N 2 atmosphere led to the formation of vanadium nitride nanoparticles that are distributed uniformly on the nanofiber surface. By changing the PAN to PAA-b-PAN-b-PAA ratio in the casting solution, a maximum specific capacitance of 240.5 F g -1 is achieved at the current density of 0.5 A g -1 with good rate capability at a capacitance retention of 72.1% at 5.0 A g -1 in an aqueous electrolyte of 6 mol L -1 KOH within the potential range of -1.10 to 0 V (rN/A = 1.5/1.0). Moreover, an asymmetric supercapacitor is assembled by using the hierarchical porous carbon fiber@vanadium nitride as the negative electrode and Ni(OH) 2 as the positive electrode. Remarkably, at the power density of 400 W kg -1 , the supercapacitor device delivers a better energy density of 39.3 W h kg -1 . It also shows excellent electrochemical stability, and thus might be used as a promising energy-storage device.

Carbon Nanotube-Based Supercapacitors with Excellent ac Line Filtering and Rate Capability via Improved Interfacial Impedance.

PubMed

Rangom, Yverick; Tang, Xiaowu Shirley; Nazar, Linda F

2015-07-28

We report the fabrication of high-performance, self-standing composite sp(2)-carbon supercapacitor electrodes using single-walled carbon nanotubes (CNTs) as conductive binder. The 3-D mesoporous mesh architecture of CNT-based composite electrodes grants unimpaired ionic transport throughout relatively thick films and allows superior performance compared to graphene-based devices at an ac line frequency of 120 Hz. Metrics of 601 μF/cm(2) with a -81° phase angle and a rate capability (RC) time constant of 199 μs are obtained for thin carbon films. The free-standing carbon films were obtained from a chlorosulfonic acid dispersion and interfaced to stainless steel current collectors with various surface treatments. CNT electrodes were able to cycle at 200 V/s and beyond, still showing a characteristic parallelepipedic cyclic votammetry shape at 1 kV/s. Current densities are measured in excess of 6400 A/g, and the electrodes retain more than 98% capacity after 1 million cycles. These promising results are attributed to a reduction of series resistance in the film through the CNT conductive network and especially to the surface treatment of the stainless steel current collector.

Recent Advances in Electrospun Nanofiber Interfaces for Biosensing Devices

PubMed Central

Sapountzi, Eleni; Braiek, Mohamed; Chateaux, Jean-François; Lagarde, Florence

2017-01-01

Electrospinning has emerged as a very powerful method combining efficiency, versatility and low cost to elaborate scalable ordered and complex nanofibrous assemblies from a rich variety of polymers. Electrospun nanofibers have demonstrated high potential for a wide spectrum of applications, including drug delivery, tissue engineering, energy conversion and storage, or physical and chemical sensors. The number of works related to biosensing devices integrating electrospun nanofibers has also increased substantially over the last decade. This review provides an overview of the current research activities and new trends in the field. Retaining the bioreceptor functionality is one of the main challenges associated with the production of nanofiber-based biosensing interfaces. The bioreceptors can be immobilized using various strategies, depending on the physical and chemical characteristics of both bioreceptors and nanofiber scaffolds, and on their interfacial interactions. The production of nanobiocomposites constituted by carbon, metal oxide or polymer electrospun nanofibers integrating bioreceptors and conductive nanomaterials (e.g., carbon nanotubes, metal nanoparticles) has been one of the major trends in the last few years. The use of electrospun nanofibers in ELISA-type bioassays, lab-on-a-chip and paper-based point-of-care devices is also highly promising. After a short and general description of electrospinning process, the different strategies to produce electrospun nanofiber biosensing interfaces are discussed. PMID:28813013

Carbon nanomaterials-based electrochemical aptasensors.

PubMed

Wang, Zonghua; Yu, Jianbo; Gui, Rijun; Jin, Hui; Xia, Yanzhi

2016-05-15

Carbon nanomaterials (CNMs) have attracted increasing attention due to their unique electrical, optical, thermal, mechanical and chemical properties. CNMs are extensively applied in electronic, optoelectronic, photovoltaic and sensing devices fields, especially in bioassay technology. These excellent properties significantly depend on not only the functional atomic structures of CNMs, but also the interactions with other materials, such as gold nanoparticles, SiO2, chitosan, etc. This review systematically summarizes applications of CNMs in electrochemical aptasensors (ECASs). Firstly, definition and development of ECASs are introduced. Secondly, different ways of ECASs about working principles, classification and construction of CNMs are illustrated. Thirdly, the applications of different CNMs used in ECASs are discussed. In this review, different types of CNMs are involved such as carbon nanotubes, graphene, graphene oxide, etc. Besides, the newly emerging CNMs and CNMs-based composites are also discoursed. Finally, we demonstrate the future prospects of CNMs-based ECASs, and some suggestions about the near future development of CNMs-based ECASs are highlighted. Copyright © 2015 Elsevier B.V. All rights reserved.

Bioelectronic Device Mimicking Human Sensory System based on Nanovesicle-Carbon Nanotube Hybrid Structure

NASA Astrophysics Data System (ADS)

Kim, Daesan; Jin, Hye; Lee, San; Kim, Tae; Park, Juhun; Song, Hyun; Park, Tai; Hong, Seunghun

2013-03-01

We have developed a nanovesicle-based bioelectronic nose (NBN) that could mimic the receptor-mediated signal transmission of human olfactory systems and recognize a specific odorant. The NBN was comprised of a single-walled carbon nanotube (CNT)-based field effect transistor and cell-derived nanovesicles containing human olfactory receptors and calcium ion signal pathways. Importantly, the NBN took advantages of cell signal pathways for sensing signal amplification. It enabled ~100 times higher sensitivity than that of previous bioelectronic noses based on only olfactory receptor protein and CNT transistors. The NBN sensors exhibited a high sensitivity of 1 fM detection limit and a human-like selectivity with single-carbon-atomic resolution. Furthermore, these sensors could mimic a receptor-mediated cellular signal transmission in live cells. This versatile sensor platform should be useful for the study of molecular recognition and biological processes on cell membranes and also for various practical applications such as food conditioning and medical diagnostics.

Processing and characterization of device solder interconnection and module attachment for power electronics modules

NASA Astrophysics Data System (ADS)

Haque, Shatil

This research is focused on the processing of an innovative three-dimensional packaging architecture for power electronics building blocks with soldered device interconnections and subsequent characterization of the module's critical interfaces. A low-cost approach termed metal posts interconnected parallel plate structure (MPIPPS) was developed for packaging high-performance modules of power electronics building blocks (PEBB). The new concept implemented direct bonding of copper posts, not wire bonding of fine aluminum wires, to interconnect power devices as well as joining the different circuit planes together. We have demonstrated the feasibility of this packaging approach by constructing PEBB modules (consisting of Insulated Gate Bipolar Transistors (IGBTs), diodes, and a few gate driver elements and passive components). In the 1st phase of module fabrication with IGBTs with Si3N 4 passivation, we had successfully fabricated packaged devices and modules using the MPIPPS technique. These modules were tested electrically and thermally, and they operated at pulse-switch and high power stages up to 6kW. However, in the 2nd phase of module fabrication with polyimide passivated devices, we experienced significant yield problems due to metallization difficulties of these devices. The under-bump metallurgy scheme for the development of a solderable interface involved sputtering of Ti-Ni-Cu and Cr-Cu, and an electroless deposition of Zn-Ni-Au metallization. The metallization process produced excellent yield in the case of Si3N4 passivated devices. However, under the same metallization schemes, devices with a polyimide passivation exhibited inconsistent electrical contact resistance. We found that organic contaminants such as hydrocarbons remain in the form of thin monolayers on the surface, even in the case of as-received devices from the manufacturer. Moreover, in the case of polyimide passivated devices, plasma cleaning introduced a few carbon constituents on the surface, which was not observed in the case of Si3N4 passivated devices. X-Ray Photoelectron Spectroscopy (XPS) Spectra showed evidence of possible carbon contaminants, such as carbide (˜282.9eV) and graphite (˜284.3eV) on the surface at binding energies below the binding energy of the hydrocarbon peak (C 1s at 285eV). Whereas above the hydrocarbon peak energy level, carbon-nitrogen compounds, single bond carbon compounds (˜285.9eV) and double bond carbon compounds (˜288.5eV) were evident. The majority of the carbon composition on the pad surface was associated with hydrocarbons, which were hydrophobic in nature, thus making the device contact pad less wettable. (Abstract shortened by UMI.)

Laser Direct Writing and Selective Metallization of Metallic Circuits for Integrated Wireless Devices.

PubMed

Cai, Jinguang; Lv, Chao; Watanabe, Akira

2018-01-10

Portable and wearable devices have attracted wide research attention due to their intimate relations with human daily life. As basic structures in the devices, the preparation of high-conductive metallic circuits or micro-circuits on flexible substrates should be facile, cost-effective, and easily integrated with other electronic units. In this work, high-conductive carbon/Ni composite structures were prepared by using a facile laser direct writing method, followed by an electroless Ni plating process, which exhibit a 3-order lower sheet resistance of less than 0.1 ohm/sq compared to original structures before plating, showing the potential for practical use. The carbon/Ni composite structures exhibited a certain flexibility and excellent anti-scratch property due to the tight deposition of Ni layers on carbon surfaces. On the basis of this approach, a wireless charging and storage device on a polyimide film was demonstrated by integrating an outer rectangle carbon/Ni composite coil for harvesting electromagnetic waves and an inner carbon micro-supercapacitor for energy storage, which can be fast charged wirelessly by a commercial wireless charger. Furthermore, a near-field communication (NFC) tag was prepared by combining a carbon/Ni composite coil for harvesting signals and a commercial IC chip for data storage, which can be used as an NFC tag for practical application.

Performance Enhancement of Organic Light-Emitting Diodes Using Electron-Injection Materials of Metal Carbonates

NASA Astrophysics Data System (ADS)

Shin, Jong-Yeol; Kim, Tae Wan; Kim, Gwi-Yeol; Lee, Su-Min; Shrestha, Bhanu; Hong, Jin-Woong

2016-05-01

Performance of organic light-emitting diodes was investigated depending on the electron-injection materials of metal carbonates (Li2CO3 and Cs2CO3 ); and number of layers. In order to improve the device efficiency, two types of devices were manufactured by using the hole-injection material (Teflon-amorphous fluoropolymer -AF) and electron-injection materials; one is a two-layer reference device ( ITO/Teflon-AF/Alq3/Al ) and the other is a three-layer device (ITO/Teflon-AF/Alq3/metal carbonate/Al). From the results of the efficiency for the devices with hole-injection layer and electron-injection layer, it was found that the electron-injection layer affects the electrical properties of the device more than the hole-injection layer. The external-quantum efficiency for the three-layer device with Li2CO3 and Cs2CO3 layer is improved by approximately six and eight times, respectively, compared with that of the two-layer reference device. It is thought that a use of electron-injection layer increases recombination rate of charge carriers by the active injection of electrons and the blocking of holes.

Scaling of Device Variability and Subthreshold Swing in Ballistic Carbon Nanotube Transistors

NASA Astrophysics Data System (ADS)

Cao, Qing; Tersoff, Jerry; Han, Shu-Jen; Penumatcha, Ashish V.

2015-08-01

In field-effect transistors, the inherent randomness of dopants and other charges is a major cause of device-to-device variability. For a quasi-one-dimensional device such as carbon nanotube transistors, even a single charge can drastically change the performance, making this a critical issue for their adoption as a practical technology. Here we calculate the effect of the random charges at the gate-oxide surface in ballistic carbon nanotube transistors, finding good agreement with the variability statistics in recent experiments. A combination of experimental and simulation results further reveals that these random charges are also a major factor limiting the subthreshold swing for nanotube transistors fabricated on thin gate dielectrics. We then establish that the scaling of the nanotube device uniformity with the gate dielectric, fixed-charge density, and device dimension is qualitatively different from conventional silicon transistors, reflecting the very different device physics of a ballistic transistor with a quasi-one-dimensional channel. The combination of gate-oxide scaling and improved control of fixed-charge density should provide the uniformity needed for large-scale integration of such novel one-dimensional transistors even at extremely scaled device dimensions.