Saturday, April 30, 2011

US Patent 7933058 - CNT heater for thermochromic display

Thermochromic materials have a color  sensitivity to heat and have been proposed as a means to develop paper thin and flexible electronic displays. This patent from Hon Hai Precision (Foxconn) teaches a way to use carbon nanotube heaters to achieve this type of electronic display. Claim 1 reads:

1. A thermochromic component, comprising:

a thermochromic module capable of changing colors under changing temperature conditions;

a heater thermally coupled with the thermochromic module and comprising a carbon nanotube structure, the carbon nanotube structure being capable of applying heat to the thermochromic module; and

two electrodes electrically connected to the heater and configured to apply a voltage to the heater.

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US Patent 7932792 - CNT RF filter

This patent is from Nokia and teaches how carbon nanotube resonators can enable nanoscale RF filters for software-defined and cognitive radio. Claim 1 reads:

1. A device comprising a nanotube configured as a resonator, a source electrode, a gate electrode, and a drain electrode, wherein a first end portion of the nanotube is fixed to the source electrode via an interposed layer of solid insulating material.


US Patent 7932549 - CNT trench capacitors

DRAM is a form of volatile semiconductor memory able to achieve high density due to a simple structure of one transistor and one capacitor and is commonly used as a main memory in personal computers. This patent from IBM teaches a way to use carbon nanotubes to fabricate the capacitors of DRAM memory cells. Claim 1 reads:

1. A trench-type storage device comprising:

a substrate;

a trench in said substrate;

multiple conductive carbon nanotubes lining said trench; and

a trench conductor, surrounded by and in direct contact with said multiple conductive carbon nanotubes, filling said trench, wherein said trench conductor and said substrate have a co-planar top surface.


Thursday, April 28, 2011

US Patent 7932543 - Zigzag nanowire crossbar

Nanowire crossbar arrays can be more sensitive to stress during manufacture due to small wire diameters which leads to broken or damaged wires. This patent from Samsung teaches a nanowire array using a zigzag arrangement to avoid this problem. Claim 1 reads:

1. A wire structure including at least one first wire, wherein the at least one first wire comprises:

a first region having a width of several to tens of nanometers; and

a second region disposed at both ends of the first region and having a width wider than that of the first region,

wherein the second region is configured to prevent the first region from at least one of bending and breaking due to a stress, the wire structure includes a plurality of first wires in parallel, and ends on one side of the plurality of the first wires are offset from one another and are in a zigzag pattern.


US Patent 7932511 - Large area nanowire arrays

This patent is from Nanosys and includes some very broad claims covering aligned nanowires deposited over a wide area surface which may be applicable to future display and sensing electronics. Claim 1 reads:

1. An article, comprising a population of nanowires disposed over a surface of a substrate, wherein:

the population of nanowires is substantially oriented in a first direction; and the surface of the substrate has an area of greater than 10 cm2.


US Patent 7932510 - Alloyed catalysts for CNT growth

This patent from Fujitsu teaches new catalyst particles for growing carbon nanotubes. Claim 1 reads:

1. A carbon nanotube containing structure comprising:

a base body;

catalytic fine particles deposited on said base body, each of the catalytic fine particles comprising alloy of Al—Fe, Zr—Co or Hf—Co; and

carbon nanotubes grown on said catalytic fine particles.


US Patent 7932477 - Electron beam heating with CNTs

One of the most commonly proposed application of carbon nanotubes is as electron emission devices which can be applied to displays, sensors, and maskless lithography. This patent from Hon Hai Precision (Foxconn) teaches how carbon nanotube strings can also form field emitters for heating. Claim 1 reads:

1. An electron beam heating system comprising:

a cathode;

an anode; and

a carbon nanotube string, wherein the carbon nanotube string comprises an end portion and an emission portion, the end portion is in direct electrical contact with the cathode, the carbon nanotube string is composed of a plurality of carbon nanotube bundles packed closely, each of the carbon nanotube bundles comprises a plurality of carbon nanotubes, the carbon nanotubes are substantially parallel to each other and are joined by van der Waals attractive force, the emission portion comprises a plurality of carbon nanotube bundles forming a tooth-shaped structure;

a chamber, wherein the cathode, the anode and the carbon nanotube string are located in the chamber.


Wednesday, April 27, 2011

US Patent 7932314 - Electrically conductive thermoplastic polymer with CNTs

This patent is from Ovation Polymer Technology and Engineered Materials and teaches a material composition used in the manufacture of an actuator for a hard disk drive including carbon nanotubes. Claim 1 reads:

1. A thermoplastic polymer composition which is comprised of

(1) from 10 weight percent to 90 weight percent polycarbonate,

(2) from 1 weight percent to 6 weight percent carbon nanotubes,

(3) from 5 weight percent to 85 weight percent of a polyethersulfone polymer,

(4) from 0.5 weight percent to 10 weight percent of a functionalized rubbery polymer, and

(5) from 0.5 weight percent to 5 weight percent of high density polyethylene as a lubricant, wherein all weight percentages are based upon the total weight of the thermoplastic polymer composition.


US Patent 7932189 - Fabrication of silicon nanocrystal memory cell

Nanocrystal films can play an important role in enhancing the reliability of nanoscale floating gate memory cells. This patent from Freescale Semiconductor teaches a fabrication method for such films. Claim 1 reads:

1. A process of forming an electronic device comprising:

forming a first layer of discontinuous storage elements over a dielectric layer, wherein: the discontinuous storage elements have an average diameter of approximately 2 to approximately 20 nm; and

at least some of the discontinuous storage elements are silicon nanocrystals;

forming a second layer over the discontinuous storage elements and substantially all of the dielectric layer, wherein the second layer is a silicon layer having a thickness in a range of approximately 3 to approximately 9 nm;

oxidizing substantially all of the second layer; and

forming a gate electrode after oxidizing substantially all of the second layer, wherein the electronic device includes a memory cell comprising a set of the discontinuous storage elements and the gate electrode.


US Patent 7931969 - Molecular fan for heat dissipation

Thermal conduction mechanisms such as heat sinks are most often used to cool electronics. However, thermal radiation can be a more efficient solution. This patent from Northern Illinois University teaches a molecular coating for facilitating radiative cooling. Claim 1 reads:

1. A molecular fan for dissipating heat, said fan comprising a chemically functionalized molecular fan thin film coating with a thickness of 1-10 μm affixed to a heat sink surface in need of heat dissipation, said molecular fan thin film coating comprising an emulsion, nanoparticles, and functionalized nanomaterials capable of assembling active vibrational groups that emit infrared radiation within said coating, and made using hazardous air pollutants-free (HAPs-free) co-solvents.


US Patent 7931941 - Synthesis of silver nanoparticles

This patent from PCHEM Associates deals with the problem of agglomeration of silver nanoparticles based on chemical reduction of metal salts in the presence of organic ligands capable of binding to the metal particle surfaces and stabilizing them against agglomeration. Claim 1 reads:

1. A method of synthesizing a metallic nanoparticle composition, comprising:

dissolving silver nitrate in water and combining the dissolved silver nitrate with an admixture comprising water, a base, a carboxylic acid including from 3 to 7 carbons, and a reducing agent, so as to give rise to one or more metallic nanoparticles comprising silver.


Tuesday, April 26, 2011

US Patent 7931884 - Welding of single walled CNTs

This patent from Honda Motor teaches a method of forming large scale interconnection of single walled carbon nanotubes which may be less harsh and cheaper than alternative methods. Claim 1 reads:

1. A method for producing interconnected single-walled carbon nanotubes (SWNTs), the method comprising:

providing a stationary electromagnetic wave in a microwave cavity, wherein the stationary electromagnetic wave has an electric field component;

positioning a sample of SWNTs in the microwave cavity at a maximum in the electric field and a minimum in a magnetic field; and

exposing the sample to a microwave field at a temperature less than 1400° C. to produce the interconnected single-walled carbon nanotubes.


US Patent 7931828 - CNT composites for gas turbine engines

Gas turbine engines include wiring harnesses subject to wear due to vibration of moving parts. This patent is from Rolls-Royce Corporation and teaches using carbon nanotube conductive composites to improve reliability. Claim 1 reads:

1. A gas turbine engine comprising:

a structure having a movable portion, a static portion, and a plurality of electrically conductive paths extending in a plurality of directions to send electrical signals to various locations of the gas turbine engine, wherein the electrically conductive paths are embedded in at least one of the movable portion and the static portion, and each of the electrically conductive paths comprises a resin sleeve impregnated with carbon nanotubes and surrounding a fiber extending through the structure.


US Patent 7931763 - TiO2 nanoadditive for solid propellant fuel

This patent is based on research from the University of Central Florida and teaches how titania nanoparticles can improve the burn rates of solid propellants. Claim 1 reads:

1. A method for enhancing solid propellant burn rates, comprising the steps of:

providing a solid propellant fuel;

providing nanoparticles of TiO2 additive, where the titania additive is 10 nm or less; and

mixing the nanoparticles of TiO2 additive with the solid propellant fuel,

wherein the nanoparticle additive function as a catalyst to modify burn rate of the fuel.


US Patent 7931049 - Fuel pipe with nanostructured metal/plastic

These patents teach how the use of nanostructured materials incorprated into fuel pipes can improve the efficiency of combustion. Claim 1 of the '049 patent reads:

1. A fuel pipe comprising a pipe body, said pipe body comprising general, nano or sub-nano metal materials and a nano or sub-nano far infrared (FIR) pipe carrier comprising a carrier body and nano or sub-nano tourmaline granules or tourmaline and germanium ore granule materials integrated into the carrier body.

Monday, April 25, 2011

US Patent 7930333 - Nanosize electron emitter for random number generation

Random number generation is important to computer and communication security. Often pseudo random number generators are used in practice but these random numbers exhibit cyclic behavior allowing them to be reproduced given sufficient time and resources. True random number generation can be based on natural random phenomena such as thermal noise. This patent teaches a new type of natural random number generator based on the stochastic behavior of nanoscale electron emitters. Claim 1 reads:

1. A method for generating true random numbers, the method comprising:

detecting field emission of electrons from a nano-size emitter (NSE) with a detector;

processing an output signal from the field emission of electrons to generate random numbers; and

detecting the field emission with a differential discriminator having a window set between an upper and lower level that accepts and transfers only true electron signals so as to eliminate accidental background radiation or amplifier noise.

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US Patent 7929133 - Nanostructured SERS surface

This patent is from Opto Trace Technologies and includes some basic claims toward nanostructured surfaces used in improving the performance of SERS sensors. Claim 1 reads:

1. A sensing device for surface-enhanced Raman spectroscopy (SERS), comprising:

a substrate;

a plurality of nano structures over the substrate, wherein at least one of the nano structures comprises an active SERS nano surface; and

an adsorption layer on the active SERS nano surface.


US Patent 7929132 - Nanoparticle fluorescence microscopy

This patent from the University of Utah Research Foundation teaches a method to improve the clarity and resolution of optical microscopes by including metal nanoparticles in a sample. Claim 1 reads:

1. A method for performing transmission microscopy on a sample material, the method comprising:

placing a sample material adjacent to a substrate comprising one or more nanoparticles;

exciting the one or more nanoparticles to cause the one or more nanoparticles to emit white light;

passing the emitted white light through the sample material; and

detecting the emitted white light that passed through the sample material.


Thursday, April 21, 2011

US Patent 7928432 - CNT molecular sensor

This patent is from researchers at Columbia University and teaches a variation of molecular sensor formed from a single walled carbon nanotube. Claim 1 reads:

1. A method of fabricating a molecular electronic device, comprising:

(a) disposing a SWNT on a base layer;

(b) disposing two or more electrodes on the SWNT;

(c) using a lithographic process to locally cut the SWNT between the electrodes to form a gap therein; and

(d) disposing a molecular wire across the gap so that each end of the molecular wire contacts an electrode.


US Patent 7927992 - CNT thermal transport

This latest patent from the nanotube electronics pioneer Nantero includes some basic claims to using carbon nanotubes for cooling electronic circuitry. Claim 1 reads:

1. A method of cooling a circuit element, the method comprising:

providing a thermal reservoir having a temperature lower than an operating temperature of the circuit element; and

providing a nanotube article in thermal contact with the circuit element and with the reservoir, the nanotube article comprising a non-woven fabric of nanotubes in contact with other nanotubes to define a plurality of thermal pathways along the article,

the nanotube article having a nanotube density and a shape selected such that the nanotube article is capable of transferring heat from the circuit element to the thermal reservoir.


US Patent 7927948 - Ion implantation nanocrystal growth

It has been proposed to use nanocrystals as a replacement for floating gates to improve the scalability of non-volatile memory transistors. However, during the manufacture of nanocrystal transistors too few nanocrystals can lead to difficulty in controlling the current in the transistor channel while too many nanocrystals results in current leakage which eliminates the ability to store charge. This patent from Micron Technology teaches a solution to optimize nanocrystal density which may improve scalability on non-volatile memory transistors into the nanoscale. Claim 1 reads:

1. A method of growing nanoscale structures on a semiconductor substrate, comprising:

implanting the semiconductor substrate with ions at a selected energy and a selected dose such that a controlled distribution of nucleation sites embedded in a surface of an insulative layer is formed, the surface disposed away from an interface formed by the insulative layer disposed on the semiconductor substrate, implanted material of the ions in the surface being the nucleation sites arranged to seed growth of nanoscale structures; and

growing conductive nanoscale structures from the nucleation sites on the insulative layer by depositing material on the nucleation sites of the implanted material in the surface.


Wednesday, April 20, 2011

US Patent 7927693 - Nanoporous hydrogen storage material

There have been several examples over the past two decades of various carbon nanomaterials such as fullerenes (e.g. C60) and nanotubes being useful as a hydrogen storage material for fuel cells. This latest patent is from Taiwan's Institute of Nuclear Energy Research Atomic Energy Council and teaches one variation which may further improve hydrogen storage capacity. Claim 1 reads:

1. A high capacity hydrogen storage material, comprising:

a microporous body, capable of absorbing hydrogen and comprising a plurality of micropores and at least a mesopore channel communicating with a plurality of nanopore channels, each nanopore channel being communicating with at least a micropore; and

a plurality of metal particles, formed at least on either surface of the mesopore or the nanopore channel, or of the micropores.


US Patent 7927651 - MSG sensor formed from nanowires

This patent is based on research conducted in South Korea indicating that silicon or carbon nanowires can be used to improve the sensitivity of biosensors for detecting the food additive MSG. Claim 1 reads:

1. A method for manufacturing a biosensor for detecting glutamate, comprising the steps of:

integrating nano wires on a surface of a solid substrate;

coating electrodes with a polymer after forming the electrodes at both ends of each of the nano wires;

adhering a functional group on the surface of the solid substrate between the nano wires;

adhering glutaraldehyde to the functional group on the surface of the solid substrate; and

immobilizing glutamate oxidase, which is capable of being bound to monosodium glutamate and catalyze the oxidative reaction of glutamate, to glutaraldehyde.

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US Patent 7927570 - Silicon nanopowder

BET theory is used to explain the adsorption of gas molecules on solid surfaces and can be used in the measurement of the specific surface area of a material.  This patent from Evonik Degussa GmbH discloses a process to form silicon nanopowder with high BET surface area useful to electronics applications. Claim 1 reads:

1. An aggregated crystalline silicon powder, comprising lithium as a doping component; wherein a proportion of lithium is up to 53 wt. %, and a BET surface area of the aggregated crystalline silicon powder is from 20 to 150 m2/g.


Tuesday, April 19, 2011

US Patent 7927567 - Filter with nanofiber filled pores

The life expectancy of air filters is often limited dependent on the specific surface area of material used as an absorbent. This patent from Sharp teaches using carbon nanofibers to enhance the surface area and improve the life expectancy and increase the effectiveness of air filters. Claim 1 reads:

1. A porous filter, comprising:

a porous member having a plurality of holes; and

a nanostructure formed on an interior hole surface of said porous member.


US Patent 7927516 - Microwave synthesis of semiconductor nanocrystals

This patent is based on research conducted within the University of California system and teaches high throughput production of quantum dots having uniform diameter. Claim 1 reads:

1. A method for chemically synthesizing nanoparticles, comprising

a heating process of a reaction system, which comprises precursors, passivants, and/or solvents in a reactor,

wherein microwave irradiation is used for the heating process, in which a temperature of constituent elements is ramped at a rate of 30° C./min or higher during the heating process.


US Patent 7926554 - Heat dissipation system using nanoparticles

Both Intel and Hon Hai Precision (Foxconn) are focusing much of their nanomaterials research on developing new systems for cooling semiconductor devices. This latest patent from Hon Hai Precision teaches one variation including boron nitride nanoparticles disposed in a cooling fluid. Claim 1 reads:

1. A liquid-cooled heat dissipation system comprising:

a heat absorber;

a heat dissipating member;

two connecting pipes connecting the heat absorber and the heat dissipating member to form a circuit; and

a working fluid filled in the heat absorber, the heat dissipating member, and the connecting pipes and being capable of circulating in the circuit;

the working fluid comprising a base fluid, and a plurality of nanoparticles and a protective agent dispersed in the base fluid, a percentage by weight of the nanoparticles in the working fluid being in a range from 0.1% to 3%.


US Patent 7926193 - Nanowire magnetic sensor

This patent from Honeywell teaches a way to use magnetic nanowires to construct a precise directional compass for use in areas where GPS is not possible. Claim 1 reads:

1. A method for fabricating a nanowire magnetic sensor, comprising:

forming a plurality of magneto-resistive (MR) nanowires on a flexible substrate,

wherein said plurality of MR nanowires are positioned to create an array of MR nanosensors, and

wherein each of said MR nanosensors in said array comprises a set of said plurality of MR nanowires, wherein said MR nanowires in said sets are each aligned in the same position for one direction; and

connecting said array MR nanosensors into at least one Wheatstone bridge configuration.


Monday, April 18, 2011

US Patent 7925452 - Corrosion detection using quantum dots

This patent from Boeing teaches a method of detecting corrosion in aircraft parts using semiconductor nanocrystals. Claim 1 reads:

1. A method for non-destructive detection of corrosion using quantum dots, the method comprising:

testing, by a number of quantum dot detectors operably coupled to a data processing system, a surface on a commodity associated with a set of quantum dots to form a test area;

detecting, by a processor of the data processing system, a pattern of wavelengths emitted by the set of quantum dots associated with the test area of the commodity to form a quantum dot pattern, wherein the set of quantum dots emits different colored lights in different sets of patterns of wavelengths; identifying, by the processor, an intensity of wavelengths in the pattern of wavelengths emitted by the set of quantum dots;

analyzing, by the processor, the quantum dot pattern to determine whether corrosion has occurred in the test area, wherein the set of quantum dots emit an expected pattern in the absence of corrosion, and wherein the corrosion changes the expected pattern; and

determining, by the processor, an amount and a severity of corrosion in the test area of the commodity based on the quantum dot pattern and the intensity of the wavelengths.


US Patent 7924514 - CNT bundle microactuator

This patent is from Hon Hai Precision (Foxconn) and teaches a form of microactuator intended for use in cameras and cellphones which uses carbon nanotubes to form the arms of the microactuator. Claim 1 reads:

1. A moveable assembly comprising:

a frame;

a plurality of resilient suspension arms each comprised of one or more carbon nanotube bundles; and

a moveable member;

the frame being disposed around the moveable member; and

each of the resilient suspension arms comprising a first end connected to the frame, and a second end connected to the moveable member, the resilient suspension arms being centro-symmetrically arranged relative to the moveable member such that the moveable member is capable of stably moving along a predetermined direction when driven by an external force.


US Patent 7924413 - Nanowire array resonator

This patent from HP teaches a way to fabricate light sensors and modulators with nanoscale dimensions based on semiconductor nanowires. Claim 1 reads:

1. A nanowire-based device comprising:

a reflective member;

a resonant cavity at least partially enclosed by the reflective member; and

at least one nanowire disposed within the resonant cavity, the nanowire including at least one active segment selectively disposed along the length of the nanowire to substantially coincide with antinodes of light to resonate within the cavity, the active segment to interact with the light to resonate within the cavity.


Thursday, April 14, 2011

US Patent 7923731 - CNTFET

Over the past decade there have been several designs of field effect transistors based on carbon nanotubes. This latest patent from Tsinghua University and Hon Hai Precision teaches a variation in which metallic nanotubes are eliminated and the nanotube layer is disordered and entangled. Claim 1 reads:

1. A thin film transistor comprising:

a source electrode;

a drain electrode spaced from the source electrode;

a semiconducting layer connected to the source electrode and the drain electrode, the semiconducting layer comprising a carbon nanotube layer, and the carbon nanotube layer comprising a plurality of semiconducting carbon nanotubes;

an insulating layer; and

a gate electrode insulated from the source electrode, the drain electrode, and the semiconducting layer by the insulating layer,

wherein the carbon nanotubes in the carbon nanotube layer are disordered, and entangled with each other.

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US Patent 7923403 - Preparing catalysts supported on CNT networks

This patent from Hyperion Catalysis teaches a way to improve the concentration and dispersion of metal catalysts within carbon nanotube networks. Claim 1 reads:

1. A method for preparing a supported catalyst comprising the steps of:

de-aggregating aggregates of carbon nanotubes to provide de-aggregated carbon nanotubes;

functionalizing said de-aggregated carbon nanotubes to provide functionalized carbon nanotubes;

loading metal catalysts onto said functionalized carbon nanotubes to provide metal loaded carbon nanotubes; and

forming a carbon nanotube network structure from said metal loaded carbon nanotubes with a linking agent.


US Patent 7923289 - Exothermically active nanoparticle paste

Nanoparticle materials often have a lower melting temperature than the equivalent material in bulk form due to a much higher available surface area. This patent from International Rectifier Corporation takes advantage of this property to bond electronic components at lower temperature. Claim 1 reads:

1. A process for fabricating a power semiconductor device, comprising:

disposing a mass of electrically conductive and exothermically active nanoparticle paste between an electrically conductive electrode of a semiconductor die and an electrically conductive support body;

applying energy to a portion of said mass of electrically conductive nanoparticle paste long enough to initiate an exothermic reaction to melt said mass, wherein said applying is discontinued before the completion of said exothermic reaction; and

cooling said molten mass to join said electrically conductive electrode to said electrically conductive support body.


US Patent 7923283 - 3D carbon integrated circuits

This patent from Fujitsu has foreign priority going back to 2001 and includes some basic claims to forming 3D integrated circuitry using carbon nanotube wiring. Claim 1 reads:

1. A method of producing an integrated circuit device comprising

a plurality of elements fabricated on a semiconductor substrate and wiring members for making the elements and the integrated circuit device function,

wherein at least part of the wiring members are formed of one or more cylindrical structures made up of carbon atoms,

the method comprising using a CVD process for the formation of the cylindrical structures, while applying an alternating current electric field so as to grow the cylindrical structures in two directions.


Wednesday, April 13, 2011

US Patent 7923109 - Inorganic nanowire with organic scaffold

This patent is based on a collaboration between the University of Texas and M.I.T. and includes some basic claims toward integrating organic matter with semiconductor nanowires. Claim 1 reads:

1. An inorganic nanowire comprising fused inorganic nanoparticles in contact with a biological scaffold, wherein the biological scaffold is a virus, a virion, or a virial subunit including capsids, or combinations thereof.

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US Patent 7923075 - Preparing nanotextured surfaces

Nanostructured surfaces can improve the display performance of LCDs and can provide protection coatings. This patent teaches a method to achieve nanostructured coatings at low cost. Claim 1 reads:

1. A method for creating a nanotextured surface, comprising

(a) depositing a polymer film on a substrate; and

(b) transforming the polymer film into uniform islands of a regularly shaped, nanometer sized template solely by a microwave-assisted hydro- or solvo-thermal treatment.


US Patent 7922965 - Slip casting nanoparticle powder for transparent ceramics

This patent is from Lawrence Livermore National Security LLC and teaches forming transparent ceramic components for lasers based on metal oxide nanopowder. Claim 1 reads:

1. A method of making a transparent ceramic, comprising the steps of:

providing nano-ceramic powders in a processed or unprocessed form,

mixing said powders with de-ionized water, said step of mixing said powders with de-ionized water producing a slurry,

sonifying said slurry to completely wet said powder and suspend said powder in said de-ionized water,

separating very fine particles from said slurry,

molding said slurry, and

curing said slurry to produce the transparent ceramic.


US Patent 7922796 - Chemically modified CNT filters

This patent from IBM teaches a molecular filter intended for use in 21st century semiconductor clean rooms which use carbon nanotube mats. Claim 1 reads:

1. A filter, comprising:

a filter housing having an inlet and a separate outlet;

a layer of porous walled and closed containers in said filter housing; and

each porous walled and closed container of said layer holding a tangled collection of individual chemically active carbon nanotubes stuck together in a mat, said chemically active carbon nanotubes comprising a chemically active layer formed on carbon nanotubes or comprising organic chemically reactive groups on sidewalls of said carbon nanotubes.


Tuesday, April 12, 2011

US Patent 7922795 - Nanoscale semiconductor membrane

This patent is from the University of Rochester and includes some broad claims toward ultrathin membranes useful to a variety of devices including electron microscopes, fuel cells, pressure sensors, and DNA sequencing. Claim 1 reads:

1. A nanoscale membrane exposed on opposite sides thereof and having an average thickness of less than about 100 nm, a lateral length to thickness aspect ratio that is more than 10,000 to 1, a surface roughness of less than about 1 nm, and wherein the membrane is formed of a semiconductor material selected from the group of silicon, germanium, silicon or germanium alloys, p-doped silicon or germanium, and n-doped silicon or germanium.


US Patent 7922787 - Silver nanowire production

Silver nanowire films have been proposed for transparent electrodes and in anti-microbial applications. This patent from Seashell Technology teaches a manufacturing method which may allow lower temperature processing. Claim 16 reads:

16. A method for the production of silver nanowires comprising reacting as reactants in a reaction a mixture of:

i) at least one polyol;

ii) at least one silver compound capable of producing silver metal when reduced; and

iii) at least one organic protective agent (OPA);

at a reaction temperature and under conditions that produce silver nanowires, wherein the silver compound is in solid form when mixed with other reactants rather than mixed as a silver solution.


US Patent 7922786 - Laser pulverized nanoparticles

This patent from Hamamatsu Photonics teaches a method to increase the efficiency of nanoparticle production via laser irradiation. Claim 1 reads:

1. A nanoparticle production method comprising:

a nanoparticle production step of producing nanoparticles by irradiating a laser light irradiation portion of a to-be-treated liquid with a laser light, wherein suspended particles are suspended, to pulverize the suspended particles in the laser light irradiation portion; and

wherein the laser light irradiation portion of the to-be-treated liquid is cooled prior to irradiation of the laser light irradiation portion with the laser light.


US Patent 7921727 - Structural monitoring with carbon nanofiber grid

This patent is from the University of Dayton teaches a way to use carbon nanofiber ink to monitor the structural integrity of structures used in aircraft, turbine blades, bridges, satellites, and ships. Claim 1 reads:

1. A sensing system for monitoring the structural health of a structure comprising:

a sensor comprising a conductive ink containing from about 4 to about 12% by weight vapor grown carbon nanofibers having a high aspect ratio and at least one polymeric resin; and

a data acquisition system;

wherein said sensor is applied in the form of a grid pattern directly to the surface of said structure.


Thursday, April 07, 2011

US Patent 7921384 - Integrated circuits for nanorobotics

This patent discloses a reconfigurable computing architecture which is speculated to enable nanorobotic devices. Claim 1 reads:

1. A system for a nano-scale FPGA, comprising:

a series of rows of nano-scale gates that are arrayed on a silicon substrate and that are configured into logic array grids;

look up tables (LUTs) in memory components on the periphery of a nano-scale device: nano-scale connectors between gates;

wherein a routing of logic arrays is done by using nano-scale connectors between the gates;

wherein the gates are structured into grids of evolvable logic arrays; wherein the logic array grids access LUTs;

wherein the logic array grids access memory on the periphery of the device;

wherein the gates reconfigure to a different position when initiated;

wherein the device contains between 1,000 and 10,000 gates;

wherein the device reconfigures its gates in response to feedback from its environment;

wherein the environment is electronic, biological or chemical; and

wherein the environment provides feedback to the device.

US Patent 7919699 - Nanotubes as mitochondrial uncoupler

Mitochondria control metabolism in individual cells by burning sugars and fats. This patent from the University of Kentucky teaches nanotubes made of metal or polymers may be useful to uncouple mitochondria, raise metabolism, and promote weight loss. Claim 1 reads:

1. A method of uncoupling mitochondria in a subject comprising:

administering nanotubes to the subject in a therapeutically effective amount, wherein the nanotubes are self-rectifying nanotubes, having a length of less than 50 nm and a conductance such that the nanotubes conduct protons only where a proton gradient of about 120-220 mV is present.


US Patent 7919184 - Phase change nanoparticles

This patent teaches a new form of nanostructured material designed to increase specific heat capacity and thermal conductivity of heat transfer fluids. Claim 1 reads:

1. A hybrid nanoparticle comprising:

a phase change material constituting an inner core of said hybrid nanoparticle, wherein the phase change material comprises one of hydrocarbons, wax, paraffins, salt hydrates, silicones, and polymers; and

an impermeable metal shell, the impermeable metal shell encapsulating the phase change material and containing said phase change material in different phases of said phase change material.

US Patent 7919037 - Molding heatable articles with nanoparticles

This patent teaches a fabrication method for molded polymer articles containing carbon nanotubes. Claim 1 reads:

1. A process for molding a part comprising:

(a) providing a mold having a mold surface containing embedded elongate nano particles uniformly distributed throughout the mold and electrical conductors embedded in said mold in spaced-apart relationship extending substantially through the mold surface;

(b) applying a resin to the mold surface;

(c) applying electrical energy to said conductors to cause said mold surface to be heated by electrical energy flowing between said conductors via said nano particle to accelerate curing of the resin forming the part; and

(d) de-molding the part.

Tuesday, April 05, 2011

US Patent 7919012 - Multi-shell dual-emitting nanocrystals

This patent from the University of Arkansas is based on a finding that certain by using multiple shells for quantum dot nanocrystals an improvement in the photoluminescence quantum yield can be achieved (from 20% to 50%). Claim 1 reads:

1. A composition comprising core/shell/shell dual-emitting nanocrystals, wherein:

the nanocrystals comprise a core material, a first shell material overcoating the core material, and a second shell material overcoating the first shell material, each of which is independently selected from a II/VI compound or a III/V compound;

the band gap of the first shell material is greater than the band gap of the core material and greater than the band gap of the second shell material; and

the as-prepared dual-emitting nanocrystals exhibit a photoluminescence comprising two bandgap emission peaks.


US Patent 7918979 - Molecular nanofluidics

This patent from Cornell has priority going back to 1999 and appears to include some basic claims to processing DNA via nanofluidic channels. Claim 1 reads:

1. A method for analyzing a nucleic acid, comprising:

a) introducing a nucleic acid molecule into an apparatus, wherein the apparatus comprises a chamber having at least a constricted nanofluidic channel connected thereto, wherein the nanofluidic channel is dimensioned to provide an entropic barrier to the nucleic acid;

b) applying a driving force across the nanofluidic channel to force the nucleic acid into the nanofluidic channel in an entropically unfavorable configuration; and

c) analyzing the nucleic acid.


US Patent 7918935 - Transistion metal oxide nanowires

Yet another basic patent from Charles Lieber's group at Harvard. This one has priority going back to 2001 and includes some basic claims to fabrication of metal oxide nanowires which may be useful to future high density, high speed non-volatile memory. Claim 1 reads:

1. A method of preparing transition-metal-oxide nanowires comprising:

a) injecting a decomposition agent into a solution comprising a solvent, a coordinating ligand, and a precursor metallic salt; and

b) heating said solution.                             


Monday, April 04, 2011

US Patent 7917298 - Nanocrystal taggants

This patent from Nanosys has relatively early priority (2003) and includes some basic claims to  using quantum dots to create invisible bar codes for inventory control. Claim 1 reads:

1. A composition for tagging objects, comprising:

a population of nanocrystals comprising two or more subsets of nanocrystals, the population characterized by a unique spectral code;

wherein each said subset comprises a plurality of quantum dots of the same size and/or the same composition;

wherein the unique spectral code of the population comprises at least one optical property defined by the interaction of the emission frequency of at least the first nanocrystal subset and the emission frequency of at least the second nanocrystal subset.


US Patent 7916530 - Mem-resistor storage matrix

This patent from Contour Semiconductor has priority going back to 2003 and appears to include some claims relevant to arrays of memory resistors which are being planned for nanoscale non-volatile memory by several different companies (HP, Sharp, Micron). This particular patent appears to teach similar subject matter from that of Unity Semiconductor patents which have slightly earlier priority but were not considered during examination (e.g. US Patent 6870755). For more details on the business developments surrounding memory resistance electronics see this link.

Claim 1 reads:

1. An addressable storage matrix facilitating control over excessive current leakage, the matrix comprising:

a first plurality of intersection points at least some of which are bridged by two-terminal non-linear elements that exhibit a threshold below which current flow is significantly lower than if the threshold is exceeded,

each non-linear element exhibiting, at a given voltage and independent of the bit state for its corresponding intersection point, a first current level or a second current level greater than the first current level,

the non-linear element exhibiting the second current level at the given voltage only if the non-linear element has been subjected to a voltage at least equal to the threshold; and

disposed at each intersection point bridged by a two-terminal non-linear element, a programmable material in series with the two-terminal non-linear element and determining a bit state for the corresponding intersection point.                             


US Patent 7915973 - Tunable multiwalled nanotube resonator

Nanoscale resonators have the potential to weigh single bacteria, detect single spins in magnetic resonance systems, and probe quantum mechanical phenomena. Silicon microstructructures can be used to create such resonators but are difficult to scale to nanometer dimensions. This patent is from the Regents of the University of California and teaches a way to produce a nanoresonator with multiwall carbon nanotubes. Claim 1 reads:

1. A tunable resonator, comprising:

a) an extendable multiwalled nanotube having two ends; and

b) an extension means attached to the two ends of the extendable multiwalled nanotube;

c) whereby the extension means relatively displaces the two ends of the attached extendable multiwalled nanotube.


Friday, April 01, 2011

HP's memristor is the greatest hoax in the history of electronics

The "memristor" is a type of circuit element in which there is a relationship between magnetic flux linkage and charge. This circuit element was proposed by a circuit theorist named Leon Chua in 1971 as a missing fourth fundamental passive circuit element after the resistor, capacitor, and inductor. In 2008 researchers at HPLabs announced they found this circuit element in the form of thin films of titanium dioxide in which oxygen vacancies acted as mobile ions.

When HP had first announced the memristor it seemed like an interesting development to me and I had a short paper at the 2008 Nano-Net conference in Boston proposing a way to use memristors for signal processing (link). I was later invited to speak at the 1st Memristor and Memristive System Symposium at UC Berkeley held in Dec. 2008 (link). This was the point where the memristor hoax started to become evident to me.

I was already aware of several companies such as Axon Technologies and Unity Semiconductor which had been working on thin films having memory resistance properties similar to the memristor for a new form of non-volatile memory called RRAM or ReRAM. At the time when HP's competitors were developing their thin film memory resistors the researchers at HP were developing molecular memory. However, they could not get their molecular memory to work well and I believe that they decided to switch to thin film memory resistors. In order to appear as an initiator rather than simply copying their competitors they used Chua's "missing" memristor as a publicity tool.

This may seem like a bold claim which is simply one opinion or point of view. However, there are some facts which may sway reasonable people toward this view. These facts become evident to anyone who actually spends some time trying to look beneath the shiny surface of HP's memristor claims. Last summer I was invited to speak at the 2010 IEEE International Symposium on Circuits and Systems and I pointed out some of the inconsistencies with HP's memristor (link). Below I review some of these defects in a form familiar to patent practitioners.

1) Novelty

HP's memristor fails to meet the requirement of novelty in view of Argall "Switching phenomena in titanium oxide thin films," Solid-State Electronics (1968) (link). Argall discloses that thin films of titanium dioxide which exhibit a zero-crossing hysteresis behavior identical to that discussed in HP's 2008 memristor paper. Argall's titanium dioxide thin films are taught to be switchable to three distinct resistance states.

In addition the importance of oxygen vacancies are discussed in patents issued to Sharp (US 6972238, filed May 21, 2003) and Samsung (US 7417271, priority Feb. 27, 2006).

2) Obviousness

Chua's original concept of the memristor is obvious in view of Bernard Widrow paper "An Adaptive ADALINE Neuron using chemical memistors," (1960) (link). This paper coins the term memistor (memory resistor) eleven years prior to Chua and exhibited the charge dependent conductance effect (Fig. 6) which Chua later used to define his memristor. The difference between Chua's memristor and Widrow's memistor is that Chua's device is 2-terminal and Widrow's device is 3-terminal. However, it was known in the 1960's that 3-terminal devices such as transistors could be converted to 2-terminal devices such as diodes by connecting two of the terminals together. It would have been obvious to a person of ordinary skill in the electronics art to connect two of the three terminals of Widrow's memistor together to form a 2-terminal memristor. The motivation for doing so would have been to facilitate miniaturization by reducing the number of required external electrical connections. 

3) Enablement

The argument made by HP's 2008 memristor paper was that the motion of oxygen vacancies or ions in thin films of titanium oxide could be modeled by similar drift-diffusion equations used to model electron motion. This leads to equations which can be modeled using the magnetic flux linkage versus charge  relationship of a memristor. However, this analysis is incorrect because it assumes that the ions can be considered to have zero mass and it neglects the repulsive forces between ions in a thin film as well as hysteresis effects from the built-in voltage of semiconductors. A more careful analysis illustrates that the behavior of ions in thin films is more properly treated in terms of a damped driven harmonic oscillation of the ions (link).


As explained above the memristor fails to meet requirements of novelty, non-obviousness, and enablement. One may argue that the researchers at HP were unaware of these issues and should not be blamed for their misunderstanding or spreading false information. However, there are additional facts which would indicate that the researchers at HP already knew that their device was not a memristor as described by Chua even as they published the 2008 memristor paper. In 2008 they conspired with Chua encouraging other researchers in RRAM (including myself) to call their device "memristors" even if they did not meet the original definition. This is an attempt by HP to gain control of a potential multi-billion dollar market for a new form of non-volatile memory which has been under development by HP's competitors. And it appears to be working.

What a disgrace.

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