Abstract: A memory array includes a plurality of memory cells, each of which receives a bit line, a first word line, and a second word line. Each memory cell includes a cell selection circuit, which allows the memory cell to be selected. Each memory cell also includes a two-terminal switching device, which includes first and second conductive terminals in electrical communication with a nanotube article. The memory array also includes a memory operation circuit, which is operably coupled to the bit line, the first word line, and the second word line of each cell. The circuit can select the cell by activating an appropriate line, and can apply appropriate electrical stimuli to an appropriate line to reprogrammably change the relative resistance of the nanotube article between the first and second terminals. The relative resistance corresponds to an informational state of the memory cell.

Abstract: Methods for forming anisotropic nanotube fabrics are disclosed. In one aspect, a nanotube application solution is rendered into a nematic state prior to its application over a substrate. In another aspect, a pump and narrow nozzle assembly are employed to realize a flow induced alignment of a plurality of individual nanotube elements as they are deposited onto a substrate element. In another aspect, nanotube adhesion promoter materials are used to form a patterned nanotube application layer, providing narrow channels over which nanotube elements will self align during an application process. Specific dip coating processes which are well suited for aiding in the creation of anisotropic nanotube fabrics are also disclosed.

Abstract: A method and apparatus for manufacture of carbon nanotubes, in which a substrate is contacted with a hydrocarbonaceous feedstock containing a catalytically effective metal to deposit the feedstock on the substrate, followed by oxidation of the deposited feedstock to remove hydrocarbonaceous and carbonaceous components from the substrate, while retaining the catalytically effective metal thereon, and contacting of the substrate having retained catalytically effective metal thereon with a carbon source material to grow carbon nanotubes on the substrate. The manufacture can be carried out with a petroleum feedstock such as an oil refining atmospheric tower residue, to produce carbon nanotubes in high volume at low cost. Also disclosed is a composite including porous material having single-walled carbon nanotubes in pores thereof.

Abstract: Methods for passivating a carbonic nanolayer (that is, material layers comprised of low dimensional carbon structures with delocalized electrons such as carbon nanotubes and nano-scopic graphene flecks) to prevent or otherwise limit the encroachment of another material layer are disclosed. In some embodiments, a sacrificial material is implanted within a porous carbonic nanolayer to fill in the voids within the porous carbonic nanolayer while one or more other material layers are applied over or alongside the carbonic nanolayer. Once the other material layers are in place, the sacrificial material is removed. In other embodiments, a non-sacrificial filler material (selected and deposited in such a way as to not impair the switching function of the carbonic nanolayer) is used to form a barrier layer within a carbonic nanolayer. In other embodiments, carbon structures are combined with and nanoscopic particles to limit the porosity of a carbonic nanolayer.

Abstract: Field programmable device (FPD) chips with large logic capacity and field programmability that are in-circuit programmable are described. FPDs use small versatile nonvolatile nanotube switches that enable efficient architectures for dense low power and high performance chip implementations and are compatible with low cost CMOS technologies and simple to integrate.

Abstract: Solutions of carbon nanotubes and methods for purifying the solutions are provided. The methods include mixing, for example, at least one complexing agents, at least one ionic species, and/or at least one buffer oxide etch (BOE) with a liquid medium containing carbon nanotubes and different types of contaminants, such as metal impurities, amorphous carbon, and/or silica particles, and performing a filtration process to the liquid medium so as to remove or reduce the contaminants in the liquid medium. As a result, carbon nanotube solutions of low contaminants are produced. In some embodiments, the solutions of this disclosure include a high concentration of carbon nanotubes and are substantially free from metal, amorphous carbon, and/or silica impurities.

Abstract: Methods and systems of using nanotube elements as joule heating elements for memories and other applications. Under one aspect, a method includes providing an electrical stimulus, regulated by a drive circuit, through a nanotube element in order to heat an adjacent article. Further, a detection circuit electrically gauges the state of the article. The article heated by the nanotube element is, in preferred embodiments, a phase changing material, hi memory applications, the invention may be used as a small-scale CRAM capable of employing small amounts of current to induce rapid, large temperature changes in a chalcogenide material. Under various embodiments of the disclosed invention, the nanotube element is composed of a non-woven nanotube fabric which is either suspended from supports and positioned adjacent to the phase change material or is disposed on a substrate and in direct contact with the phase change material.

Abstract: The present disclosure provides a nanotube solution being treated with a molecular additive, a nanotube film having enhanced adhesion property due to the treatment of the molecular additive, and methods for forming the nanotube solution and the nanotube film. The nanotube solution includes a liquid medium, nanotubes in the liquid medium, and a molecular additive in the liquid medium, wherein the molecular additive includes molecules that provide source elements for forming a group IV oxide within the nanotube solution. The molecular additive can introduce silicon (Si) and/or germanium (Ge) in the liquid medium, such that nominal silicon and/or germanium concentrations of the nanotube solution ranges from about 5 ppm to about 60 ppm.

Abstract: Under one aspect, a non-volatile nanotube diode device includes first and second terminals; a semiconductor element including a cathode and an anode, and capable of forming a conductive pathway between the cathode and anode in response to electrical stimulus applied to the first conductive terminal; and a nanotube switching element including a nanotube fabric article in electrical communication with the semiconductive element, the nanotube fabric article disposed between and capable of forming a conductive pathway between the semiconductor element and the second terminal, wherein electrical stimuli on the first and second terminals causes a plurality of logic states.

Abstract: Inverter circuits and NAND circuits comprising nanotube based FETs and methods of making the same are described. Such circuits can be fabricating using field effect transistors comprising a source, a drain, a channel region, and a gate, wherein the first channel region includes a fabric of semiconducting nanotubes of a given conductivity type. Such FETs can be arranged to provide inverter circuits in either two-dimension or three-dimensional (stacked) layouts. Design equations based upon consideration of the electrical characteristics of the nanotubes are described which permit optimization of circuit design layout based upon constants that are indicative of the current carrying capacity of the nanotube fabrics of different FETs.

Abstract: Light emitters using nanotubes and methods of making same. A light emitter includes a nanotube article in electrical communication with a first and a second contact, a substrate having a predefined region with a relatively low thermal conductivity said region in predefined physical relation to said nanotube article; and a stimulus circuit in electrical communication with the first and second contacts. The stimulus circuit provides electrical stimulation sufficient to induce light emission from the nanotube article in the proximity of the predefined region. The predefined region is a channel formed in the substrate or a region of material with relatively low thermal conductivity. The light emitter can be integrated with semiconductor circuits including CMOS circuits. The light emitter can be integrated into optical driver circuits (on- and off-chip drivers) and opto-isolators.

Abstract: Photovoltaic (PV) devices employing layers of semiconducting carbon nanotubes as light absorption elements are disclosed. In one aspect a layer of p-type carbon nanotubes and a layer of n-type carbon nanotubes are used to form a p-n junction PV device. In another aspect a mixed layer of p-type and n-type carbon nanotubes are used to form a bulk hetero-junction PV device. In another aspect a metal such as a low work function metal electrode is formed adjacent to a layer of semiconducting nanotubes to form a Schottky barrier PV device. In another aspect various material deposition techniques well suited to working with nanotube layers are employed to realize a practical metal-insulator-semiconductor (MIS) PV device. In another aspect layers of metallic nanotubes are used to provide flexible electrode elements for PV devices. In another aspect layers of metallic nanotubes are used to provide transparent electrode elements for PV devices.

Abstract: Methods of making non-volatile field effect devices and arrays of same. Under one embodiment, a method of making a non-volatile field effect device includes providing a substrate with a field effect device formed therein. The field effect device includes a source, drain and gate with a field-modulatable channel between the source and drain. An electromechanically-deflectable, nanotube switching element is formed over the field effect device. Terminals and corresponding interconnect are provided to correspond to each of the source, drain and gate such that the nanotube switching element is electrically positioned between one of the source, drain and gate and its corresponding terminal, and such that the others of said source, drain and gate are directly connected to their corresponding terminals.

Abstract: Carbon Nanotube Films, Layers, Fabrics, Ribbons, Elements and Articles are disclosed. To make various articles, certain embodiments provide a substrate. Preformed nanotubes are applied to a surface of the substrate to create a non-woven fabric of carbon nanotubes. Portions of the non-woven fabric are selectively removed according to a defined pattern to create the article. To make a nanofabric, a substrate is provided. Preformed nanotubes are applied to a surface of the substrate to create a non-woven fabric of carbon nanotubes wherein the non-woven fabric is substantially uniform density. The nanofabrics and articles have characteristics desirable for various electrical systems such as memory circuits and conductive traces and pads.

Abstract: A method for controlling density, porosity and/or gap size within a nanotube fabric layer is disclosed. In one aspect, this can be accomplished by controlling the degree of rafting in a nanotube fabric. In one aspect, the method includes adjusting the concentration of individual nanotube elements dispersed in a nanotube application solution. A high concentration of individual nanotube elements will tend to promote rafting in a nanotube fabric layer formed using such a nanotube application solution, whereas a lower concentration will tend to discourage rafting. In another aspect, the method includes adjusting the concentration of ionic particles dispersed in a nanotube application solution. A low concentration of ionic particles will tend to promote rafting in a nanotube fabric layer formed using such a nanotube application solution, whereas a higher concentration will tend to discourage rafting. In other aspects, both concentration parameters are adjusted.

Abstract: Under one aspect, a system (100) for sensing the presense of an analyte in a fluid includes a nanotube sensor element including a plurality of nanotubes and positioned for exposure to a fluid; an optical source capable of generating optical radiation (102), the radiation having a source frequency and a fluence selected to generate a nonlinear optical response by the nanotube sensor element; an optical detector (110) capable of measuring the nonlinear optical response by the nanotube sensor element; and logic in electrical communications with the optical detector to sense the presense of an analyte in the fluid based on the nonlinear optical response measured by the optical detector.

Abstract: Field effect devices having channels of nanofabric and methods of making same. A nanotube field effect transistor is made to have a substrate, and a drain region and a source region in spaced relation relative to each other. A channel region is formed from a fabric of nanotubes, in which the nanotubes of the channel region are substantially all of the same semiconducting type of nanotubes. At least one gate is formed in proximity to the channel region so that the gate may be used to modulate the conductivity of the channel region so that a conductive path may be formed between the drain and source region. Forming a channel region includes forming a fabric of nanotubes in which the fabric has both semiconducting and metallic nanotubes and the fabric is processed to remove substantially all of the metallic nanotubes.

Abstract: Sensor platforms and methods of making them are described. A platform having a non-horizontally oriented sensor element comprising one or more nanostructures such as nanotubes is described. Under certain embodiments, a sensor element has or is made to have an affinity for an analyte. Under certain embodiments, such a sensor element comprises one or more pristine nanotubes. Under certain embodiments, the sensor element comprises derivatized or functionalized nanotubes. Under certain embodiments, a sensor is made by providing a support structure; providing one or more nanotubes on the structure to provide material for a sensor element; and providing circuitry to electrically sense the sensor element's electrical characterization. Under certain embodiments, the sensor element comprises pre-derivatized or pre-functionalized nanotubes. Under other embodiments, sensor material is derivatized or functionalized after provision on the structure or after patterning.

Abstract: Field programmable device (FPD) chips with large logic capacity and field programmability that are in-circuit programmable are described. FPDs use small versatile nonvolatile nanotube switches that enable efficient architectures for dense low power and high performance chip implementations and are compatible with low cost CMOS technologies and simple to integrate.

Abstract: Certain spin-coatable liquids and application techniques are described, which can be used to form nanotube films or fabrics of controlled properties. A spin-coatable liquid for formation of a nanotube film includes a liquid medium containing a controlled concentration of purified nanotubes, wherein the controlled concentration is sufficient to form a nanotube fabric or film of preselected density and uniformity, and wherein the spin-coatable liquid comprises less than 1×1018 atoms/cm3 of metal impurities. The spin-coatable liquid is substantially free of particle impurities having a diameter of greater than about 500 nm.