Abstract: A field emission device having bundles of aligned parallel carbon nanotubes on a substrate. The carbon nanotubes are oriented perpendicular to the substrate. The carbon nanotube bundles may be up to 300 microns tall, for example. The bundles of carbon nanotubes extend only from regions of the substrate patterned with a catalyst material. Preferably, the catalyst material is iron oxide. The substrate is preferably porous silicon, as this produces the highest quality, most well-aligned nanotubes. Smooth, nonporous silicon or quartz can also be used as the substrate. The method of the invention starts with forming a porous layer on a silicon substrate by electrochemical etching. Then, a thin layer of iron is deposited on the porous layer in patterned regions. The iron is then oxidized into iron oxide, and then the substrate is exposed to ethylene gas at elevated temperature. The iron oxide catalyzes the formation of bundles of aligned parallel carbon nanotubes which grow perpendicular to the substrate surface.

Abstract: Carbon nanotubes are functionalized in a broadly applicable manner. According to an example embodiment of the present invention, single-wall carbon nanotubes (SWNTs) are noncovalently functionalized. The functionalized SWNTs are highly versatile, being useful for a variety of implementations, including for the immobilization of molecules, for circuit arrangements, molecular electronics and for molecular sensors. In addition, stable suspensions of functionalized SWNTs in solutions can be achieved, as well as the self-assembly of nanotubes with unperturbed sp2 structures and thus their electronic characteristics.

Abstract: Carbon nanotubes are implemented in a manner that facilitates their orientation and arrangement for a variety of applications. According to an example embodiment of the present invention, an electric field is used to orient carbon nanotubes along a direction of the electric field (e.g., along a direction generally parallel to an electric field applied between two electrodes). In one implementation, the electric field is used to orient a nanotube that has already been grown. In another implementation, the electric field is used in situ, with nanotubes being aligned while they are grown. With these approaches, carbon nanotubes can be selectively oriented for one or more of a variety of implementations. Furthermore, arrays of aligned carbon nanotubes can be formed extending between circuit nodes having both similar and different orientations.

Abstract: This invention relates generally to the end derivatization of single-wall carbon nanotubes and to the introduction of endohedral groups to single-wall carbon nanotubes. In one embodiment, the single-wall carbon nanotubes are chemically derivatized at their ends (which may be made either open or closed with a hemi-fullerene dome). In another embodiment, the single-wall carbon nanotubes can be modified endohedrally, such as, for example, by including one or more metal atoms inside the structure or, alternatively, by loading the single-wall carbon nanotubes with one or more smaller molecules that do not bond to the structures.

Abstract: This invention relates generally to a method for producing single-wall carbon nanotube (SWNT) catalyst supports and compositions thereof. In one embodiment, SWNTs or SWNT structures can be employed as the support material. A transition metal catalyst is added to the SWNT. In a preferred embodiment, the catalyst metal cluster is deposited on the open nanotube end by a docking process that insures optimum location for the subsequent growth reaction. The metal atoms may be subjected to reductive conditions.

Abstract: Carbon nanotube growth is achieved in a high-yield process. According to an example embodiment of the present invention, a furnace chamber is adapted to grow a carbon nanotube device via catalyst islands. The carbon nanotube device includes a catalyst island, such as Fe2O3, and a carbon nanotube extending therefrom. In one more specific implementation, the catalyst island is disposed on a top surface of a substrate. The carbon nanotube device is useful in a variety of implementations and applications, such as in an atomic force microscope (AFM), in resonators (e.g., where a free end of the carbon nanotube is adapted to vibrate) and in electronic circuits (e.g., where the carbon nanotube is electrically coupled between two nodes, such as between the catalyst island and a circuit node). In addition, growing carbon nanotubes with such a catalyst island is particularly useful in the high-yield growth of a large number of nanotubes.

Abstract: Carbon nanotube devices are manipulated in a manner that is useful for a variety of implementations. According to an example embodiment of the present invention, light (632) is used to photodesorb molecules from a carbon nanotube (620).

Abstract: Nanowires are formed using an approach that facilitates efficient and economical growth thereof. According to an example embodiment of the present invention, a gas including a semiconducting material (e.g., single-crystal germanium) is introduced to a conductive metal particle (e.g., gold) on an insulating substrate to grow a nanowire therefrom. In one implementation, an alloy is formed from the semiconducting material and the conductive metal particle, with the nanowire being grown from the alloy. In another implementation, a co-flow of hydrogen is used with the gas including the semiconducting material to facilitate the growth of the nanowire.

Abstract: Carbon nanotube circuits are implemented with high-&kgr; dielectrics. According to one example embodiment of the present invention, a carbon nanotube circuit includes at least one carbon nanotube with a high-&kgr; dielectric material. In one implementation, a gate electrode is capacitively coupled to the carbon nanotube via the high-&kgr; dielectric material. Voltage applied to the gate electrode is thus capacitively coupled to the carbon nanotube to control, for example, electrical characteristics of the carbon nanotube. With this approach, the carbon nanotube circuit exhibits voltage-controllable characteristics that can be used for a variety of implementations.

Abstract: This invention relates generally to a method for growing carbon fiber from single-wall carbon nanotube (SWNT) molecular arrays. The carbon fiber which comprises an aggregation of substantially parallel carbon nanotubes may be produced by growth (elongation) of a suitable seed molecular array. The first step is to open the growth end of the SWNTs in the molecular array. Next, a transition metal catalyst is added to the open-ended seed array. In the next step, the SWNT molecular array with catalyst deposited on the open tube ends is subjected to tube growth (extension) conditions. The carbon supply necessary to grow the SWNT molecular array into a continuous fiber is supplied to the SWNT molecular array tip heated to a temperature sufficient to cause growth to any desired length. The continuous carbon fiber can also be grown from more than one separately prepared molecular arrays or templates.

Abstract: This invention relates generally to a method for growing single-wall carbon nanotube (SWNT) from seed molecules. The supported or unsupported SWNT seed materials can be combined with a suitable growth catalyst by opening SWNT molecule ends and depositing a metal atom cluster. In one embodiment, a suspension of seed particles containing attached catalysts is injected into an evaporation zone to provide an entrained reactive nanoparticle. A carbonaceous feedstock gas is then introduced into the nanoparticle stream under conditions to grow single-wall carbon nanotubes. Recovery of the product produced can be done by filtration, centrifugation and the like.

Abstract: This invention relates generally to a method for growing carbon fiber from single-wall carbon nanotube (SWNT) molecular arrays. In one embodiment, the present invention involves a macroscopic molecular array of at least about 106 tubular carbon molecules in generally parallel orientation and having substantially similar lengths in the range of from about 50 to about 500 nanometers. The hemispheric fullerene cap is removed from the upper ends of the tubular carbon molecules in the array. The upper ends of the tubular carbon molecules in the array are then contacted with a catalytic metal. A gaseous source of carbon is supplied to the end of the array while localized energy is applied to the end of the array in order to heat the end to a temperature in the range of about 500° C. to about 1300° C. The growing carbon fiber is continuously recovered.

Abstract: A method for purifying a mixture comprising single-wall carbon nanotubes and amorphous carbon contaminate is disclosed. The method includes the steps of heating the mixture under oxidizing conditions sufficient to remove the amorphous carbon, followed by recovering a product comprising at least about 80% by weight of single-wall carbon nanotubes. A method for producing tubular carbon molecules of about 5 to 500 nm in length is also disclosed. The method includes the steps of cutting single-wall nanotube containing-material to form a mixture of tubular carbon molecules having lengths in the range of 5-500 nm and isolating a fraction of the molecules having substantially equal lengths. The nanotubes may be used, singularly or in multiples, in power transmission cables, in solar cells, in batteries, as antennas, as molecular electronics, as probes and manipulators, and in composites.

Abstract: Macroscopically manipulable nanoscale devices made from nanotube assemblies are disclosed. The article of manufacture comprises a macroscopic mounting element capable of being manipulated or observed in a macroscale environment, and a nanoscale nanotube assembly attached to the mounting element. The article permits macroscale information to be provided to or obtained from a nanoscale environment. A method for making a macroscopically manipulable nanoscale devices comprises the steps of (1) providing a nanotube-containing material; (2) preparing a nanotube assembly device having at least one carbon nanotube for attachment; and (3) attaching said nanotube assembly to a surface of a mounting element.

Abstract: Macroscopically manipulable nanoscale devices made from nanotube assemblies are disclosed. The article of manufacture comprises a macroscopic mounting element capable of being manipulated or observed in a macroscale environment, and a nanoscale nanotube assembly attached to the mounting element. The article permits macroscale information to be provided to or obtained from a nanoscale environment. A method for making a macroscopically manipulable nanoscale devices comprises the steps of (1) providing a nanotube-containing material; (2) preparing a nanotube assembly device having at least one carbon nanotube for attachment; and (3) attaching said nanotube assembly to a surface of a mounting element.

Abstract: Macroscopically manipulable nanoscale devices made from nanotube assemblies are disclosed. The article of manufacture comprises a macroscopic mounting element capable of being manipulated or observed in a macroscale environment, and a nanoscale nanotube assembly attached to the mounting element. The article permits macroscale information to be provided to or obtained from a nanoscale environment. A method for making a macroscopically manipulable nanoscale devices comprises the steps of (1) providing a nanotube-containing material; (2) preparing a nanotube assembly device having at least one carbon nanotube for attachment; and (3) attaching said nanotube assembly to a surface of a mounting element.

Abstract: Nanotubes and nanotube-based devices are implemented in a variety of applications. According to an example embodiment of the present invention, a nanotube device is manufactured having a nanotube extending between two conductive elements. In one implementation, each conductive element includes a catalyst portion, wherein electrical connection is made to opposite ends of the nanotube at each of the catalyst portions. In one implementation, the conductive elements are coupled to circuitry for detecting an electrical characteristic of the nanotube, such as the response of the nanotube to exposure to one or more of a variety of materials. In another implementation, the nanotube device is adapted for chemical and biological sensing. In still another implementation, a particular functionality is imparted to the nanotube using one or more of a variety of materials coupled to the nanotube, such as metal particles, biological particles and/or layers of the same.

Abstract: Carbon nanotube growth is achieved in a high-yield process. According to an example embodiment of the present invention, a carbon nanotube device includes a catalyst island, such as Fe2O3, and a carbon nanotube extending therefrom. In one implementation, the catalyst island is disposed on a top surface of a substrate. The carbon nanotube device is useful in a variety of implementations and applications, such as in an atomic force microscope (AFM), in resonators (e.g., where a free end of the carbon nanotube is adapted to vibrate) and in electronic circuits (e.g., where the carbon nanotube is electrically coupled between two nodes, such as between the catalyst island and a circuit node). In addition, growing carbon nanotubes with such a catalyst island is particularly useful in the high-yield growth of a large number of nanotubes.

Abstract: This invention provides an assembly of novel nanotube devices that can be employed in a variety of applications. In particular, the nanotube devices of the present invention provide a new class of versatile chemical and biological sensors. The present invention describes methods for growing individual nanotubes in a controlled fashion and for manipulating and integrating the nanotubes into functional devices. It further provides methods for modifying the nanotubes such that their sensitivity to a wide range of chemical and biological species can be achieved.

Abstract: Macroscopically manipulable nanoscale devices made from nanotube assemblies are disclosed. The article of manufacture comprises a macroscopic mounting element capable of being manipulable or observed in a macroscale environment, and a nanoscale nanotube assembly attached to the mounting element. The article permits macroscale information to be provided to or obtained from a nanoscale environment. A method for making a macroscopically manipulable nanoscale devices comprises the steps of (1) providing a nanotube-containing material; (2) preparing a nanotube assembly device having at least one carbon nanotube for attachment; and (3) attaching said nanotube assembly to a surface of a mounting element.