Static and dynamic strain sensing using a polymer : carbon nanotube film strain sensor

The search for new multipoint, multidirectional strain sensing devices has received a new impetus since the discovery of carbon nanotubes. The excellent electrical, mechanical, and electromechanical properties of carbon nanotubes make them ideal candidates as primary materials in the design of this new generation of sensing devices. Carbon nanotube based strain sensors proposed so far include those based on individual carbon nanotubes for integration in nano or micro elecromechanical systems (NEMS/MEMS) [1], or carbon nanotube films consisting of spatially connected carbon nanotubes [2], carbon nanotube - polymer composites [3,4] for macroscale strain sensing. Carbon nanotube films have good strain sensing response and offer the possibility of multidirectional and multipoint strain sensing, but have poor performance due to weak interaction between carbon nanotubes. In addition, the carbon nanotube film sensor is extremely fragile and difficult to handle and install. We report here the static and dynamic strain sensing characteristics as well as temperature effects of a sandwich carbon nanotube - polymer sensor fabricated by infiltrating carbon nanotube films with polymer

Electrical and Structural Analysis of CNT-Metal Contacts in Via Interconnects

Vertically aligned carbon nanotubes grown by plasmaenhanced chemical vapor deposition offer a potentially suitable material for via interconnects in next-generation integrated circuits. Key performance-limiting factors include high contact resistance and low carbon nanotube packing density, which fall short of meeting the requirements delineated in the ITRS roadmap for interconnects. For individual carbon nanotube s, contact resistance is a major performance hurdle since it is the dominant component of carbon nanotube interconnect resistance, even in the case of vertically aligned carbon nanotube arrays. In this study, we correlate the carbon nanotube-metal interface nanostructure to their electrical properties in order to elucidate growth parameters that can lead to high density and low contact resistance and resistivity

SINTESIS CARBON NANOTUBE DENGAN METODE SPRAY PYROLYSIS DAN APLIKASINYA UNTUK ADSORPSI BENZENA

Telah dilakukan sintesis carbon nanotube (CNT) menggunakan metode spray pyrolysis dengan benzena (C6H6) sebagai sumber karbon dan ferrocene (Fe( ױ5-C5H5)2) sebagai sumber katalis. Sintesis dilakukan dengan menginjeksikan benzena-ferrocene ke dalam furnace dengan variasi temperatur 700oC, 800oC, 900oC dan 1.000oC. Hasil sintesis dianalisis menggunakan Scanning Electron Microscopy (SEM), Energy Dispersive X-ray Spectroscopy (EDS) dan X-ray Diffraction (XRD). Carbon nanotube yang dihasilkan kemudian dimurnikan dengan mencucinya menggunakan HNO3 dengan variasi konsentrasi 0 %, 45 %, 65 %, 85 % dan dianalisis menggunakan Energy Dispersive X-ray Spectroscopy (EDS). Hasil pemurnian carbon nanotube tersebut kemudian diaplikasikan untuk adsorpsi benzena. Hasil analisis menunjukkan bahwa jumlah carbon nanotube yang dihasilkan meningkat seiring dengan peningkatan temperatur, sedangkan diameternya akan menurun seiring dengan naiknya temperatur, temperatur terbaik diperoleh pada 900oC. Kemurnian carbon nanotube yang terbaik diperoleh pada konsentrasi HNO3 65% dan adsorpsi terbaik didapatkan pada carbon nanotube yang dimurnikan dengan HNO3 65%

A survey of carbon nanotube interconnects for energy efficient integrated circuits

This article is a review of the state-of-art carbon nanotube interconnects for Silicon application with respect to the recent literature. Amongst all the research on carbon nanotube interconnects, those discussed here cover 1) challenges with current copper interconnects, 2) process & growth of carbon nanotube interconnects compatible with back-end-of-line integration, and 3) modeling and simulation for circuit-level benchmarking and performance prediction. The focus is on the evolution of carbon nanotube interconnects from the process, theoretical modeling, and experimental characterization to on-chip interconnect applications. We provide an overview of the current advancements on carbon nanotube interconnects and also regarding the prospects for designing energy efficient integrated circuits. Each selected category is presented in an accessible manner aiming to serve as a survey and informative cornerstone on carbon nanotube interconnects relevant to students and scientists belonging to a range of fields from physics, processing to circuit design

Carbon nanotube reinforced nanocomposites for energy conversion and storage

CNT-reinforced foams comprised of three-dimensional (3D) interconnected macropores with uniform mesoporous walls were developed as multifunctional nanocomposites and tested for electrochemical energy conversion and storage. Multi-walled CNTs grown on the wall surface of the interconnected scaffold structure of carbon foams were found to improve the surface area and electrochemical properties of the nanocomposites. The lightweight CNT-reinforced nanocomposites not only exhibit high structural flexibility, but also possess enhanced electrocatalytic performance for HER at current density of 10 mA cm−2 with overpotentials of 240 mV. In addition, these nanocomposites can be used as flexible, electric double layer capacitor electrodes, and have achieved a specific capacitance of 776 F g−1, with excellent durability and stability after 1000 cycles

Fermi-level alignment at metal-carbon nanotube interfaces: application to scanning tunneling spectroscopy

At any metal-carbon nanotube interface there is charge transfer and the induced interfacial field determines the position of the carbon nanotube band structure relative to the metal Fermi-level. In the case of a single-wall carbon nanotube (SWNT) supported on a gold substrate, we show that the charge transfers induce a local electrostatic potential perturbation which gives rise to the observed Fermi-level shift in scanning tunneling spectroscopy (STS) measurements. We also discuss the relevance of this study to recent experiments on carbon nanotube transistors and argue that the Fermi-level alignment will be different for carbon nanotube transistors with low resistance and high resistance contacts.Comment: 4 pages, 3 ps figures, minor corrections, accepted by Phys. Rev. Let

Transport in coupled graphene-nanotube quantum devices

We report on the fabrication and characterization of all-carbon hybrid quantum devices based on graphene and single-walled carbon nanotubes. We discuss both, carbon nanotube quantum dot devices with graphene charge detectors and nanotube quantum dots with graphene leads. The devices are fabricated by chemical vapor deposition growth of carbon nanotubes and subsequent structuring of mechanically exfoliated graphene. We study the detection of individual charging events in the carbon nanotube quantum dot by a nearby graphene nanoribbon and show that they lead to changes of up to 20% of the conductance maxima in the graphene nanoribbon acting as a good performing charge detector. Moreover, we discuss an electrically coupled graphene-nanotube junction, which exhibits a tunneling barrier with tunneling rates in the low GHz regime. This allows to observe Coulomb blockade on a carbon nanotube quantum dot with graphene source and drain leads

Nanopencil as a wear-tolerant probe for ultrahigh density data storage

A dielectric-sheathed carbon nanotube probe, resembling a “nanopencil,” has been fabricated by conformal deposition of silicon-oxide on a carbon nanotube and subsequent “sharpening” to expose its tip. The high aspect-ratio nanopencil probe takes advantage of the small nanotube electrode size, while avoiding bending and buckling issues encountered with naked or polymer-coated carbon nanotube probes. Since the effective electrode diameter of the probe would not change even after significant wear, it is capable of long-lasting read/write operations in contact mode with a bit size of several nanometers

Texture development in Fe-doped alumina ceramics via templated grain growth and their application to carbon nanotube growth

Fe-doped alumina (Fe-Al2O3) materials with a controlled microstructure could be designed for some special uses such as a substrate for carbon nanotube growth. In this study, Fe-doped Al2O3 ceramics with varying degrees of texture were prepared via Templated Grain Growth method and utilized for carbon nanotube synthesis by Catalytic Chemical Vapor Deposition in order to investigate how alpha-Al2O3 crystal orientation affects carbon nanotube growth in polycrystalline ceramics. The degree of texture increased with the Fe content in the presence of liquid phase. Three kinds of carbon filaments (few-wall carbon nanotubes bundles, individual multi-wall nanotubes and carbon nanofibres) were observed over Fe-doped Al2O3 ceramics with varying degrees of texture depending on the surface roughness, crystallographic orientation and the size of the catalyst nanoparticles. While well-textured substrates with a rough surface led to a small amount of randomly oriented carbon nanotube bundles, perpendicularly oriented individual multi-wall nanotubes were obtained over relatively smooth single crystal alpha-Al2O3 platelet surfaces (basal planes) which remained in the matrix without growing

Molecular Dynamics Simulation of Stationary and Rotating Nanotube in Uniform Liquid Argon Flow

This paper was presented at the 4th Micro and Nano Flows Conference (MNF2014), which was held at University College, London, UK. The conference was organised by Brunel University and supported by the Italian Union of Thermofluiddynamics, IPEM, the Process Intensification Network, the Institution of Mechanical Engineers, the Heat Transfer Society, HEXAG - the Heat Exchange Action Group, and the Energy Institute, ASME Press, LCN London Centre for Nanotechnology, UCL University College London, UCL Engineering, the International NanoScience Community, www.nanopaprika.eu.In this paper molecular dynamics (MD) simulation is used to investigate the liquid argon flow past a stationary and rotating carbon nanotube. The main purpose of this work is to estimate flow forces on the nanotube and compare them with classical continuum results. The simulation is 3D and consists of 33,700 liquid argon atoms as fluid and 240 atoms of carbon as the nanotube. The single walled nanotube is simulated as a rigid cylinder of fixed carbon atoms. For simulation of rotating carbon nanotube, carbon atoms are rotated around center axes of the nanotube in each times step according to the desired angular velocity. Both argon-argon and carbon-argon interactions are modeled by Lennard-Jones potential function. Periodic boundary condition is used for the whole system. Flow is driven by rescaling velocities at the inlet each 50 time steps. The results show that the rotation of nanotube causes a reduction in drag force, up to rotation rate of 3.0 where the drag force is about 78% of the stationary one. Above the rotation rate of 3.0 drag coefficient is almost constant. Lift coefficient of stationary nanotube is negligible in comparison with drag coefficient and the rotation of nanotube has a little influence on the lift coefficient