Friday, May 28, 2010

US Patent 7723729 - Silicon nanowire buffer layer

Gallium nitride (GaN) is a semiconductor material having applicability in fabrication of blue LEDs and lasers. However, a problem with forming GaN on silicon is thermal and lattice mismatch which usually requires complicated buffering materials or extra fabrication process steps. This patent from Sharp teaches a way to use silicon nanowires as a buffer layer to simplify the process. Claim 1 reads:

1. A compound semiconductor-on-silicon (Si) wafer with a Si nanowire buffer layer, the wafer comprising:

a Si substrate;

an insulator layer overlying the Si substrate, with Si nanowires having compound semiconductor-coated tips; and,

a compound semiconductor layer overlying the insulator.


US Patent 7723684 - SWCNT infrared detector

Although this is not the first patent for a CNT infrared detector (see US 6400088) it teaches a variation capable of counting individual photons having energies of around 1 eV. Claim 1 reads:

1. An infrared (IR) detector, comprising:

a sensor element comprising a thin film of single-walled carbon nanotubes (SWNTs) suspended between electrical contacts.


US Patent 7723223 - Method of doping CNT transistor

Controlled doping of semiconductor material with foreign atoms is a necessary process to manufacture transistors with predictable characteristics. This patent from Samsung teaches a method of such controlled doping for field effect transistors formed using carbon nanotube channels. Claim 1 reads:

1. A method of doping a carbon nanotube (CNT) of a field effect transistor comprising:

providing a source, a drain, the CNT as a channel between the source and the drain, and a gate on a substrate;

applying a first voltage to the gate; and

adsorbing ions on a surface of the CNT.


Thursday, May 27, 2010

US Patent 7723100 - Polymer coated SERS nanotag

This patent from Becton, Dickenson and Co. teaches glass coated metal nanoparticles having improved biocompatibility in biological systems over quantum dot nanotags. Claim 1 reads:

1. A coated nanotag comprising:

a SERS-active nanotag; and

a polymer coating completely covering the SERS active nanotag,

wherein the SERS-active nanotag comprises: a core comprising one or more nanoparticles, a Raman-active molecule attached to or associated with the core, and an encapsulant.

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US Patent 7722787 - Metal vanadium oxide nanoparticles

This patent from Greatbatch Ltd. has relatively early priority (2/5/1999) and includes some basic claims to metal vanadium oxide nanoparticles used in forming the anodes of lithium ion batteries. Claim 1 reads:

1. A collection of particles comprising metal vanadium oxide, the particles having an average diameter less than about 1 micron and wherein less than about 1 particle in 1,000,000 has a diameter greater than about four times the average diameter of the collection of particles.


US Patent 7721347 - Nanotube characterization using RF scanning probe

RF Nano is a company focusing on developing CMOS compatible carbon nanotubes for applications in radio frequency, analog, and mixed signal electronics. This patent discloses a scanning probe device used to characterize the physical and electrical properties of nanotubes. Claim 1 reads:

1. A device for determining an electrical characteristic of a nanotube material without contacting the nanotube material, comprising:

a scanning probe configured to generate a signal of certain frequency onto the nanotube material and measure a reflected signal from the nanotube material; and

a processor coupled to the scanning probe and configured to determine the electrical characteristic of the nanotube material from the measured reflected signal.


Wednesday, May 26, 2010

US Patent 7721242 - Nanotube circuit analysis software

This patent from Intellectual Ventures teaches a software-based system for taking a template of carbon nanotubes and selectively removing portions to create useful circuit connections. Claim 1 reads:

1. A method of editing a carbon nanotube (CNT) template structure, comprising:

accessing via a processor a model representative of the carbon nanotube (CNT) template structure, the model representative of the CNT template structure including representations of a plurality of junctions interconnected by CNT segments, wherein each segment and junction has an associated electrical behavior;

identifying at least one first proposed editing step selected from the group consisting of deleting at least one of the CNT segments or junctions; and

connecting two CNT segments, the identified two CNT segments being in physical proximity; and

determining via a processor a first predicted response of the CNT template structure to an electrical signal if the identified first proposed editing step were performed.


US Patent 7720326 - Nanowire array photodetector

Researchers from HP have found that arrays of nanowires can be used to convert optical signals into photocurrent. This patent teaches a way to apply this finding in developing photonic integrated circuits. Claim 1 reads:

1. A photodetector comprising:

a waveguide configured to transmit one or more channels of electromagnetic radiation;

a first terminal and a second terminal, the first terminal and the second terminal positioned on opposite sides of the waveguide; and

a number of nanowires, each nanowire interconnects the first terminal to the second terminal and a portion of each nanowire is embedded in the waveguide.


US Patent 7719951 - Inclined microtip data recorder

High density (i.e. >Terabit/cm2) data storage has been demonstrated using scanning probe tips having individual nanotubes fixed or grown onto a cantilever tip. However, using individual scanning probe tips limits the maximum rate of data reading and writing. This patent teaches using arrays of inclined carbon nanotubes tips formed on a flat substrate in order to increase read and write speeds. Claim 1 reads:

1. Data recording device, comprising

a network of carbon nanotubes constituting microtips cooperating with a substantially flat storage medium, device

wherein the carbon nanotubes are formed on a substantially flat substrate that is parallel to the storage medium, and are inclined with respect to the plane of the substrate.


Tuesday, May 25, 2010

US Patent 7719678 - Non-uniform periodic diameter nanowire

Most often it is desirable to fabricate nanowires having a uniform diameter. However, this patent from researchers at HP teaches that non-uniform diameter nanowires can actually assist in forming optical-to-electrical conversion devices. Claim 1 reads:

1. A nanowire structure, comprising:

a substrate;

at least one nanowire attached to the substrate, the at least one nanowire having a circumferential surface and a diameter that varies generally periodically along a length of the at least one nanowire; and

a coating covering at least part of the circumferential surface of the at least one nanowire.


US Patent 7719067 - Vertical nanotube switch

Nantero has been developing prototypes of a variety of micromechanical switching devices based on carbon nanotubes for almost ten years. Originally the focus was on horizontally oriented nanotube crossbar fabrics but in order to increase manufacturing yield vertically oriented nanotubes may be preferable. This is one of Nantero's basic patents for this approach. Claim 1 reads:

1. An nanotube switching device, comprising:

a structure having a major horizontal surface and a channel formed therein, the channel having a vertical wall and first and second electrodes each forming a portion of the vertical wall;

a nanotube article vertically disposed in the channel and in contact with said first and second electrodes, the nanotube article responsive to electrical stimulus to form and unform an electrically conductive pathway between said first and second electrodes.


US Patent 7719032 - MWCNT transistor

Multiwall carbon nanotubes tend to have metallic rather than semiconductor electronic properties and thus have conventionally been considered inappropriate to form transistor channels. However, this patent from Sony teaches a way to use the inner carbon shell as the electrode contact and the outer carbon shell as a semiconductor channel which may allow multiwall carbon nanotube transistors (although mass production could be problematic).
Claim 5 reads:

5. An electronic device including a multi-walled carbon nanotube having at least two layers, the electronic device comprising:

a field effect transistor comprising:

an outer carbon nanotube having semiconductivity;

an inner carbon nanotube that is partially included in the outer carbon nanotube;

a current-input terminal that inputs current to the outer carbon nanotube;

a current-output terminal that outputs current from the outer carbon nanotube; and

an electrode in contact with the inner carbon nanotube and applying voltage to the inner carbon nanotube to control operation of a conduction channel of the field effect transistor formed in the outer carbon nanotube between the current-input terminal and the current-output terminal.


US Patent 7718995 - Particle coated nanowire

In order to enhance the surface area and sensitivity of nanowire-based sensors this patent from Panasonic teaches techniques to form semiconductor nanoparticles on the surface of a semiconductor nanowire. Claim 1 reads:

1. A nanowire comprising:

a nanowire body made of a crystalline semiconductor as a first material; and

a plurality of fine particles, which are made of a second material, including a constituent element of the semiconductor, and which are located on at least portions of the surface of the nanowire body, wherein the surface of the nanowire body is smooth.


Sunday, May 16, 2010

US Patent 7714798 - CNT yarn antenna

This patent from Nanocomp Technologies teaches how to use carbon nanotube yarn to construct antennas which minimize signal distortion. Claim 1 reads:

1. An antenna comprising:

a body portion;

an aggregate of extended length nanotubes along the body portion; and

a plurality of contact points between adjacent nanotubes to permit transmission of electromagnetic radiation while reducing resistivity at a high frequency.


US Patent 7714577 - CNT RF coil for MRI

In order to improve the signal-to-noise ratio of magnetic resonance imaging coils this patent form Tursiop Technologies teaches using carbon nanotubes as the coil material. Claim 1 reads:

1. A magnetic resonance imaging system having an enhanced signal-to-noise ratio, the system comprising:

a magnet system for providing a static magnetic field having a low magnetic field strength; and

at least one RF receiving coil assembly including: a coiled electrical conducting element consisting essentially of carbon nanotube material; and RF receiving circuitry having a large quality factor.


Thursday, May 13, 2010

US Patent 7714330 - Silicon nanowire on insulator substrate

Silicon-on-insulator (SOI) technology has been advantageous over bulk silicon in the fabrication of transistors in order to avoid parasitic electrical effects while facilitating scaling. However, SOI uses amorphous silicon or polysilicon which has a lower mobility compared to crystalline bulk silicon resulting in a lower speed operation. This patent from Samsung teaches a silicon nanowire on insulator substrate achieving the benefits of SOI but with improved mobility. Claim 1 reads:

1. A silicon nanowire substrate comprising:

a substrate;

an insulating film formed on the substrate in a strip shape such that all side surfaces of the strip shape meet a bottom surface of the strip shape, the insulating film having exposed side surfaces; and

a silicon nanowire film covering an uppermost surface of the insulating film and having sidewalls aligned with the exposed side surfaces of the insulating film, wherein the silicon nanowire film is single crystalline silicon.


US Patent 7714317 - Semiconductor nanomaterial with carbon shell

This patent from Brookhaven Science Associates teaches using carbon coating to avoid oxidation of Ge and GaN nanowires. Claim 1 reads:

1. An encapsulated semiconducting nanomaterial comprising:

a semiconducting nanomaterial having a diameter and a surface, the diameter of the semiconducting nanomaterial having a magnitude between about 1 nm and about 100 nm;

an encapsulant, the encapsulant enclosing the semiconducting nanomaterial and comprising an ordered carbon shell; and

an interface between the ordered carbon shell and the semiconducting nanomaterial, the interface decorated with islands of metal.


US Patent 7713753 - 2-level self-assembled patterning

Block copolymers have been shown to self-assemble into periodic nanoscale patterns when deposited onto a substrate which can be useful to maskless lithography. This patent from Seagate Technology teaches a multi-layer self-assembly method with block copolymers. Claim 1 reads:

1. A method of fabricating a device comprising:

providing a substrate having a patterned surface;

depositing a first-level block copolymer self-assembled material on at least a portion of the patterned surface, wherein the position and/or orientation of the first-level self-assembled material is directed by the patterned surface, to form a first nanostructure pattern; and

depositing a second-level self-assembled material on at least a portion of the first nanostructure pattern to form an array of nanostructures of the second-level self-assembled material.


Wednesday, May 12, 2010

US Patent 7713589 - Improved CVD nanotube fabrication

Chemical vapor deposition is a technique used to grow carbon nanotubes from catalytic particles by exposing the catalysts to hydrocarbon gases at high temperatures. This patent from Hon Hai Precision teaches a way to lower the temperature of CVD nanotube growth while improving the speed and yield of growth. Claim 1 reads:

1. A method for making an array of carbon nanotubes, comprising the steps of:

(a) providing a substrate with a film of catalyst provided thereon;

(b) disposing the substrate in a reaction chamber;

(c) supplying a carrier gas into the reaction chamber and heating the reaction chamber to a predetermined temperature; and

(d) introducing a carbon source gas and a hydrogen gas into the reaction chamber separately and simultaneously;

the hydrogen gas being introduced such that the hydrogen gas has less of a distance to travel in the reaction chamber than does the carbon source gas to reach the substrate.


US Patent 7713508 - Thiation of carbon nanotube

This patent from Arrowhead Center teaches a new method for functionalizing carbon nanotubes to increase interfacial binding in composites. Claim 1 reads:

1. A method of functionalizing at least one nanotube comprising:

carboxylizing the at least one nanotube;

reacting the at least one nanotube with a catalyst;

activating at least one carboxylic functional group on the at least one nanotube for nucleophilic attack; and

thiolating at least one hydroxyl and carbonyl functional group thereby thiolating the at least one nanotube.


US Patent 7712512 - Manufacturing metal/nanocarbon composite

Carbon nanostructures have the potential to improve the strength and thermal properties of metal alloys but can be difficult to evenly distribute within a metal matrix. This patent from Nissei Plastic Industrial Co. teaches a method to improve the dispersibility of nanocarbon with metal. Claim 1 reads:

1. A method for manufacturing a composite metal material combined with a nanocarbon material, the method comprising the steps of:

heating a metal alloy to a half-melted state in which both liquid and solid phases are present; and

adding a nongraphitized nanocarbon material to the half-melted metal alloy and stirring to obtain a composite metal material combined with a nanocarbon.


Tuesday, May 11, 2010

US Patent 7711213 - Nanowire array optical modulator

This patent from HP teaches an optical modulator for photonic integrated circuits in which semiconductor nanowires act as the modulator. Claim 1 reads:

1. A modulator comprising:

a waveguide configured to transmit one or more channels of electromagnetic radiation;

a first terminal and a second terminal the first terminal and the second terminal positioned on opposite sides of the waveguide; and

a number of nanowires, wherein the nanowires are randomly spaced and randomly oriented and each nanowire interconnects the first terminal to the second terminal, a portion of each nanowire is operatively coupled to the waveguide, and wherein the nanowires are configured to modulate the one or more channels when an electrical signal is applied to the first and second terminals, the electrical signal causing electro-absorption of the one or more channels at the nanowires.


US Patent 7710709 - CNT coated capacitor electrodes

This patent from Intel teaches the use of carbon nanotubes in forming electrodes for a capacitor which produces a large capacitance with lower thermal mismatch to organic substrates than ceramic capacitors. Claim 1 reads:

1. A device comprising:

a substrate;

a capacitor formed on the substrate, the capacitor comprising first and second electrodes and a capacitor dielectric between the first and second electrodes;

wherein at least one of the first and second electrodes comprises a metal layer and carbon nanotubes coupled thereto; and

wherein a plurality of the carbon nanotubes are in contact with the capacitor dielectric.


Sunday, May 09, 2010

US Patent 7710649 - CNT optical polarizer

This patent is from Hon Hai Precision and teaches the fabrication of carbon nanotube films used as optical polarizers for LCDs. Claim 1 reads:

1. An optical polarizer, comprising:

a supporting member; and

a polarizing film supported by the supporting member, the polarizing film comprises a plurality of layers of carbon nanotube films stacked on each other, and the layers of carbon nanotube films are secured to one another by van de Waals attractive force, each carbon nanotube film being comprised of a plurality of carbon nanotubes, the carbon nanotubes in a given carbon nanotube film all being aligned in a same direction.


US Patent 7710635 - MEMS hinge memory mitigation

Hinge memory is a problem for microelectromechanical devices which spend a vast majority of time in a single position resulting in an inability to change position. This patent from Texas Instruments provides movement to hinged MEMS devices during inactive periods to avoid this problem. Claim 1 reads:

1. A method for reducing hinge memory in a micromechanical device, the method comprising:

operating each element in the device with a specified duty cycle during an inactive period, wherein the duty cycle specifies a ratio of a number of times that the element is in a first state to a number of times that the element is in a second state.


US Patent 7710235 - Spiral nanocoil inductor

This patent from Northrop Grumman teaches the manufacture of inductive microstructures fabricated from silicon nitride/silicon nanocoils and applied to RF-MEMS. Claim 6 reads:

6. An inductor comprising:

a spiral nanocoil tube with a plurality of spiral coils adjacent to each other, in which the spiral coils have a substantially constant pitch, the spiral nanocoil tube defines an air core, and the spiral nanocoil tube is fabricated from material providing inductance when a current is applied to the spiral nanocoil tube;

wherein the nanocoil tube has a radius of approximately 7 microns.


Thursday, May 06, 2010

US Patent 7709923 - Metal-base nanowire transistor

Several decades ago metal-base transistors were proposes as a replacement for the purely semiconductor bipolar transistors. This patent from NXP Semiconductor attempts to introduce a nanowire version of the metal base transistor to achieve higher speed switching. Claim 1 reads:

1. Transistor comprising

a first, a second electrode, and base electrode to control current flow between the first and second electrode,

wherein the first electrode is made from a semiconducting material,

wherein the base electrode is a metal layer deposited on top of the semiconducting material forming the first electrode,

characterized in that the second electrode is formed by a semiconducting nanowire being in electrical contact with the base electrode.


US Patent 7709127 - Nanocatalytic recharging composition

QuantumSphere is a company dedicated to enabling breakthrough performance in portable power and clean-technology. This is one of their patents focusing on a portable cartridge for refueling fuel cells. Claim 1 reads:

1. A portable cartridge comprising an electro-catalytic fueling composition suitable for use in recharging an electrochemical system, the composition comprising:

an electrolyte and catalytic nanoparticles,

wherein the composition is in solid phase suitable for storage within the portable cartridge, and

wherein the portable cartridge is configured to permit the introduction of fluid therein to change the phase of the composition from solid to liquid.


US Patent 7709103 - Axial heterostructure nanophosphor

This patent from Sharp teaches nitride-based semiconductor nanophosphors which are noted to be easier to disperse and provide higher luminous efficiency than other nanophosphors. Claim 1 reads:

1. A phosphor formed of a columnar crystal having a diameter of at most 3 nm, wherein a light emitting region and a light absorbing region are defined in the columnar crystal, and said light emitting region and the light absorbing region are adjacent to each other along a longitudinal direction of said columnar crystal.


Wednesday, May 05, 2010

US Patent 7709054 - Spin coating fabrication of particle-rod nanostructures

This patent from Wayne State University teaches a way to connect nanoparticles and nanorods in a predefined manner using spin coating. Claim 1 reads:

1. A method of forming a particle-rod nanostructure, the method comprising:

preparing a mixture comprising an inorganic nanoparticle and an organic molecule in a solvent; and

spin-coating the mixture to nucleate the crystal growth of the organic molecule on the inorganic nanoparticle that is deposited on a substrate, yielding the particle-rod nanostructure.


US Patent 7708974 - Tungsten nanopowder

This patent from PPG Industries Ohio teaches a new type of nanopowder having potential applications as pigments, catalysts, or phosphors. Claim 1 reads:

1. A nanomaterial composition of matter comprising

(a) non-stoichiometric nanoparticles of tungsten oxide, and

(b) at least one metal other than tungsten, wherein the composition comprises a tungsten bronze.


US Patent 7707962 - CNT spray nozzles

This patent from Hon Hai Precision teaches a spray nozzle assembly for forming carbon nanotube films having a high level of thickness uniformity. Claim 1 reads:

1. An apparatus for forming a carbon nanotube film, the apparatus comprising:

a retaining member,

an array of spray nozzles, and

a supply tube configured for supplying a carbon-nanotube-containing solution therethrough,

the spray nozzles being retained on the retaining member, the spray nozzles being in communication with the supply tube, the retaining member comprising a slit defined therein, the retaining member further comprising a through hole defined therein along a longitudinal direction thereof, each of the spray nozzles including a fixing portion received in the through hole, each spray nozzle being retainably engaged in the slit, a plurality of feed tubes, each of the spray nozzles being in communication with the supply tube through the corresponding feed tube.


Monday, May 03, 2010

US Patent 7707647 - Metal nanoparticle spectroscopic probe

This patent from Canon teaches a new type of scanning probe structure using metallic nanoparticles formed on a cantilever tip. Claim 1 reads:

1. A probe for use in surface enhanced vibrational spectroscopic analysis, the probe being formed on a cantilever, the probe comprising a plurality of metal fine particles dispersed therein, the plurality of the metal fine particles being exposed on a surface of the probe.


US Patent 7706422 - Graded density q-dot laser

This patent from Mitsubishi Electric teaches a way to increase the emission efficiency of quantum dot lasers by altering the quantum dot distribution. Claim 1 reads:

1. A semiconductor optical element comprising an active layer including quantum dots, wherein density of the quantum dots in a resonator direction in a portion of the active layer in which density of photons is relatively high is higher relative to the density of the quantum dots in a portion of the active layer in which the density of photons is relatively low.


Sunday, May 02, 2010

US Patent 7705989 - Surface plasmon nanosensor pads

This patent teaches a variation of an SPR sensor for detecting biological and chemical specimens. Claim 1 reads:

1. A surface plasmon microsensor or nanosensor for chemical or biological species, comprising:

metallic, cylindrical pads distributed on the surface of a support, the pads having a thickness between 10 nm and 500 nm and configured to immobilize the chemical or biological species, and the pads having a dimension, other than the thickness, that is less than 1 micron.


US Patent 7705523 - Hybrid solar nanogenerator

This patent from Georgia Tech. Research teaches a power generator using both solar and mechanical (e.g. wind) sources of energy so as to generate power continuously over a range of changing environments. Claim 1 reads:

1. A hybrid solar and mechanical power generator, comprising:

a. a solar power generating portion electrically coupled to a first electrode; and

b. a piezoelectric nanowire vibrational power generating portion including:

i. an electrical contact structure electrically coupled to and extending downwardly from the first electrode and disposed adjacent to the solar power generating portion; and

ii. a plurality of piezoelectric semiconductor nanorods extending upwardly from a second electrode, spaced apart from the first electrode, so as to be directed toward the electrical contact structure and configured to release electrons across a Schottky barrier formed between the piezoelectric semiconductor nanorods and the electrical contact structure when mechanical energy is applied to the piezoelectric nanowire vibrational power generating portion.


US Patent 7705347 - N-type CNTFET

In order to replicate CMOS device electronics with carbon nanotubes it is required to dope the nanotubes to be both electron donors (n-type) and electron acceptors (p-type). This patent from Samsung teaches a method to form n-type CNT transistors. Claim 1 reads:

1. An n-type CNT FET comprising:

a conductive substrate;

a gate oxide layer formed on the conductive substrate;

electrodes formed on the gate oxide layer and separated from each other; and

a CNT formed on the gate oxide layer and electrically connected to the electrodes;

wherein the gate oxide layer contains electron donor atoms which donate electrons to the CNT such that the CNT is n-doped by the electron donor atoms.