Sunday, February 28, 2010

US Patent 7667260 - Nanorod floating gate memory cell

In order to continue the scaling of flash memory there has been an increase in patents which incorporate nanostructures in memory cell design. This latest patent from Micron teaches a structure which reduced parasitic capacitance effects using a nanorod floating gate. Claim 1 reads:

1. A memory cell, comprising:

a tunnel dielectric layer overlying a semiconductor substrate;

a floating gate having a conductive first layer overlying the tunnel dielectric layer and a conductive nanorod having a longest dimension extending from the conductive first layer in an approximately perpendicular direction relative to the surface of the tunnel dielectric layer; and

a control gate layer separated from the floating gate by an intergate dielectric layer.


US Patent 7666939 - Stable CNT dispersion in polymer

A variety of techniques have been employed to uniformly disperse carbon nanotubes in polymers. However, over days or weeks it has been observed that phase separation of the nanotubes and polymer occurs indicating thermodynamic instability. This patent from NASA teaches the use of electron donating and electron accepting functional groups to increase long term dispersion. Claim 1 reads:

1. A dispersion of carbon nanotubes in a polymer matrix, which dispersion exhibits long term stability, the dispersion comprising:

carbon nanotubes, which have been introduced into a polymer matrix and separated therein;

the polymer matrix having moieties therein which are capable of a donor-acceptor complexation with the carbon nanotubes.


US Patent 7666708 - Uniform nanowire growth

This patent from the Lieber Research Group of Harvard has relatively early priority (~2000) and includes some basic claims to the fabrication and structure of doped nanowire semiconductors. Claim 1 reads:

1. A method, comprising:

growing a population of semiconductor nanowires, each having at least one portion having a smallest width less than 500 nanometers, catalytically from catalyst particles having a variation in diameter of less than about 20% and being selected such that the population of semiconductor nanowires produced according to the method has a variation in diameter of less than 20%.

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Thursday, February 25, 2010

US Patent 7666494 - Metal nanoparticle transfer sheet

Arrays of metal nanoparticles have been used in applications such as Surface Enhanced Raman Spectroscopy, magnetic storage, and as catalysts for the formation of nanowires or nanotubes on a substrate. This patent from 3M teaches an article to facilitate the transfer of metal nanoparticles onto substrates. Claim 1 reads:

1. An article comprising a microporous membrane and a discontinuous non-conductive coating of metallic nanoparticles directly thereon wherein the metallic nanoparticles comprise individual particles or agglomerates of particles having an average major dimension of 1 to 50 nm.


US Patent 7666465 - Nanotube in trench fabrication

This patent from Intel teaches an approach to incorporate nanotubes in a semiconductor substrate along the length of openings formed in the substrate. Claim 1 reads:

1. A method of forming a structure comprising:

providing a substrate comprising at least one opening; and

applying a nanotube slurry comprising at least one nanotube to the substrate by utilizing a mechanical process,

wherein the at least one nanotube is substantially placed within the at least one opening, and

wherein a length of the at least one nanotube is oriented substantially parallel with a length of the at least one opening.


US Patent 7666382 - CNT applicator liquid

Nantero is a leading company in developing techniques to incorporate carbon nanotubes into microelectronic systems. This latest patent is fundamental to an applicator liquid producing nanotube films suitable for microfabrication. Claim 1 reads:

1. An applicator liquid comprising:

one or more carbon nanotubes and an electronics-grade liquid medium comprising water,

wherein the carbon nanotubes are distributed in the liquid medium without substantial precipitation, flocculation or other macroscopic interaction and can remain separated for about at least one week,

wherein the nanotubes are at a concentration of greater than or equal to 10 mg/L,

wherein the nanotubes are pretreated to reduce a level of metal impurities to less than about 1×1018 atoms/cm3,

wherein the applicator liquid is substantially free of polymers and surfactants, and

wherein the applicator liquid is substantially free of particulates having a diameter greater than about 500 nm.


Wednesday, February 24, 2010

US Patent 7666051 - Field emission cloth using nanostructures

Carbon nanomaterials have been proposed to create electron emission devices by companies including Applied Nanotech, Canon, and Samsung. This patent from Boston College teaches a way to of growing such nanomaterials directly from a carbon cloth achieving emission current densities of 1mA/cm2 at a field of 0.4V/micron. Claim 13 reads:

13. A device capable of delivering an enhanced field emission current density at a low electric field comprising:

a conductive cloth substrate woven of fiber bundles oriented in at least two directions, wherein the conductive cloth substrate has a rough finish; and

a plurality of nanostructures grown on the conductive cloth substrate.


US Patent 7665985 - CNT ignition mixture

Spark igniters are most commonly used for ignition systems used in many combustion processes. However, it is often desirable to have multiple ignition points throughout the combustion volume to improve efficiency and reduce engine size. This patent from ERC Incorporated teaches a system using a dispersion of single walled carbon nanotubes (SWCNTs)as well as other nanostructured materials to generate multiple ignition sites. Claim 1 reads:

1. An apparatus comprising:

a. a combustion chamber in communication with an intake line;

b. a first injector coupled to said intake line, for porting an injectable fuel from a fuel supply into said combustion chamber;

c. a second injector coupled to said intake line, for porting an injectable ignition mixture from an ignition mixture supply into said combustion chamber

said ignition mixture comprising numerous light-ignitable ignition agents and said fuel, said ignition agents comprising at least SWCNTs, such that said ignition agents are spatially distributed to multiple points within said combustion chamber along with said fuel in the presence of oxygen; and

d. a light source communicating diffused light radiation into said combustion chamber, and wherein said light radiation initiates combustion of said ignition agents at said distributed multiple points within said combustion chamber and thereby igniting said fuel within said chamber.


US Patent 7665672 - Anti-static liner using conductive nanofiber

This patent is from Illinois Tool Works and teaches a liner for spray paint and other fluid applicators which uses conductive nanofibers to remove static and generate more uniform coatings. Claim 1 reads:

1. A disposable liner comprising:

at least one side wall defining a volume for containing material having chargeable particles therein,

the disposable liner being see-through wherein the liner comprises a polymeric material containing conductive nanofibers preventing chargeable particles in a coating mixture from sticking to the disposable liner so that uniformity of the coating mixture is maintained while it is dispensed.


Monday, February 22, 2010

US Patent 7663226 - CNT solder resist

This patent from Samsung teaches increasing the thermal conductivity of solder used in PCBs by incorporating carbon nanotubes. Claim 5 reads:

5. A semiconductor chip package comprising:

a semiconductor chip;

an insulation layer configured to have the semiconductor chip mounted thereon and having a circuit pattern formed on a surface thereof; and

a solder resist stacked on the insulation layer, wherein the solder resist contains carbon nanotubes.

One relevant prior art patent which appears to have been overlooked is from Intel.

US Patent 7180174 - Nanotube modified solder thermal intermediate structure, systems, and methods (title)


US Patent 7663202 - Nanowire photodiode

This patent from HP teaches a way to integrate fiber optics technology with semiconductor nanowires in order to create nanoscale photodiodes. Claim 1 reads:

1. A nanowire photodiode, comprising:

a first optical waveguide comprising a tapered first end including a first tip;

a second optical waveguide comprising a tapered second end including a second tip spaced from the first tip; and

at least one nanowire comprising at least one semiconductor material, the nanowire connecting the first tip and the second tip in a bridging configuration.


Sunday, February 21, 2010

US Patent 7663057 - CIGS nanoparticle ink for photovoltaics

This latest patent from Nanosolar teaches the production of a higher quality solar energy absorber using nanoparticle ink. Claim 1 reads:

1. A method comprising:

providing a suspension comprised of one or more liquid metals, wherein the one or more liquid metals comprises at least one group IIIA based material;

providing a plurality of nanoparticles, wherein the nanoparticles comprise at least one group IB based material; and

mixing the nanoparticles and the suspension to form an ink configured to be processed in one or more steps into a photovoltaic absorber layer.


US Patent 7662873 - Nanobarcode for textiles

This patent from Nano-Tex has a relatively early priority date (Feb.22,2003) and includes some basic claims to using metallic nanoparticles as a type of barcode for tracking textiles, paper, or other fibrous materials. Claim 4 reads:

4. A treatment preparation for introducing nanoscopic bar codes to a fibrous substrate, the treatment preparation comprising nanoscopic nanobar code particles, a fluorescent dye or fluorophore, a particles binder, and water.

Some prior art not cited but which may have some relevance to the claims include:

US Patent 6617583- "A novel encoding system and methods for determining the location and/or identity of a particular item or component of interest is provided. In particular, the present invention utilizes a "barcode" comprising one or more sizes of semiconductor nanocrystals (quantum dots) having characteristic spectral emissions, to either "track" the location of a particular item of interest or to identify a particular item of interest. " (from abstract)

US Patent 6633370-"Quantum dots, semiconductor nanocrystals and semiconductor particles used as fluorescent coding elements" (title)


US Patent 7662732 - Preparation of planar patterned CNT array

Porous templates such as anodic alumina have frequently been used to form vertically aligned arrays of nanotubes and nanowires for use in applications such as field emission displays and chemical sensors. This patent from Samsung teaches another method involving porous templates to form horizontally aligned carbon nanotube arrays to manufacture transparent electrodes. Claim 1 reads:

1. A method of preparing a patterned carbon nanotube array, the method comprising:

providing a plurality of porous templates, each of the porous templates including a plurality of hollow channels formed therein;

respectively forming carbon nanotubes in each of the plurality of hollow channels of the porous templates;

arranging the plurality of porous templates including the carbon nanotubes in a predetermined pattern on a surface of a substrate, wherein a longitudinal direction of the plurality of porous templates is disposed substantially parallel to the surface of the substrate; and

selectively removing the plurality of porous templates and exposing the carbon nanotubes on the substrate.


Thursday, February 18, 2010

US Patent 7662731 - Q-dot manipulation in superfluid

This patent is from Japan Science and Technology Agency and teaches a way to manipulate and sort quantum dots using a system similar to optical tweezers in a superfluid environment and which may be useful to experiments in quantum computing. Claim 1 reads:

1. A method of manipulating a plurality of quantum dots that differ in at least one of size, shape and internal structure in a superfluid helium, said method comprising:

generating a plurality of quantum dots directly in the superfluid helium;

shining light onto said plurality of quantum dots generated in the superfluid helium;

selecting, using said light, specific quantum dots from said plurality of quantum dots, said specific quantum dots being in resonance with said light; and

manipulating, using said light, only said specific quantum dots being in resonance with said light.


US Patent 7662648 - IC inspection using nanotube electron emitters

Carbon nanotubes have been employed as electron emitters in numerous applications such as flat panel displays, pressure sensors, and as e-beam lithography. This patent from Micron Technology introduces a new application in testing integrated circuits. Claim 1 reads:

1. A method, comprising:

selectively activating one or more nanotubes of a plurality of nanotubes to emit an electrical signal toward aligned regions of a substrate, wherein the one or more nanotubes are alignable with features of the substrate and adapted to emit the signal to the substrate when activated;

sensing a current generated by the electrical signal, the current flowing through the substrate;

comparing the current to a reference current; and

determining whether a via is completely formed in the substrate based on the comparison.


US Patent 7662321 - Graphene plate alignment for nanocomposites

Alignment of nanostructures generally helps to optimize the mechanical strength and electrical conductivity of nanocomposite materials. This patent from Nanotek Instruments teaches an alignment method applicable to graphene nanostructures. Claim 1 reads:

1. A method of making a nanocomposite material with a preferred orientation, said method comprising:

(a) providing a mixture of nano-scaled graphene plates (NGPs) and a matrix material in a fluent state;

(b) extruding said mixture to form a filament wherein said nano-scaled graphene plates are aligned along a filament axis;

(c) aligning a plurality of segments of said filament in a first direction, or moving said filament back and forth along a first direction and its opposite direction, to form a NGP-matrix filament preform; and

(d) consolidating said preform to form said nanocomposite material.


Wednesday, February 17, 2010

US Patent 7662300 - Method of preparing nanoporous material

Nanoporous materials have been suggested to improve the efficiency of energy storage and conversion devices such as supercapacitors and fuel cells. This patent from Samsung teaches a method for controlling the size and uniformity of the nanopores in such materials. Claim 1 reads:

1. A method for preparing a porous material using nanostructures, the method comprising the steps of:

(a) producing nanostructures using a porous template;

(b) dispersing the nanostructures in a source or a precursor material for a porous material;

(c) aligning the nanostructures in a particular direction; and

(d) removing the nanostructures by etching.


US Patent 7662298 - Density gradient separation of CNTs

This patent is from Northwestern University and teaches a technique called density gradient ultracentrifugation allowing for segregation of single walled carbon nanotubes based on their bandgap. An article on the process is available here. Claim 1 reads:

1. A method of using a density gradient to separate single-walled carbon nanotubes, said method comprising:

centrifuging a nanotube composition in contact with a fluid medium comprising a density gradient; and

separating the nanotube composition into two or more separation fractions,

wherein said nanotube composition comprises single-walled carbon nanotubes of mixed nanotube diameters, chiralities, electronic types, or combinations thereof and at least one surface active component; and

at least one of said two or more separation fractions is enriched with single-walled carbon nanotubes of a selected nanotube diameter, chirality, electronic type, or combinations thereof relative to the nanotube composition.


US Patent 7662288 - Nanobubble water pretreatment

This patent from Sharp teaches a way to induce nanoscale bubbles in water in order to activate aerobic or anaerobic microorganisms and help recycle waste water. Claim 1 reads:

1. A water treatment method, comprising:

a first step of introducing micro-nano bubbles of air or nitrogen into at least one of a plurality of upstream water treatment devices to produce treatment water; and

a second step of pretreating said treatment water to produce pretreatment water and treating said pretreatment water in a downstream waste water treatment device.


Tuesday, February 09, 2010

US Patent 7659631 - Microscale to nanoscale electronic interconnect

There have been a variety of suggestions to integrate nanoelectronic circuit architectures based on crossbars with microelectronic circuit architectures based on CMOS. However, due to differences in the pitch and wiring dimensions this is not an easy task. This patent represents one solution proposed by HP using a tapered electrical interconnect. Claim 1 reads:

1. A hybrid-scale electronic circuit comprising:

a nanoelectronic circuit having a nano-scale electrical contact;

a microelectronic circuit having a micro-scale electrical contact; and

an interconnect extending through an insulator layer that separates the nanoelectronic circuit and the microelectronic circuit, the interconnect having a tapered shape, such that a first end of the interconnect has an end dimension that is at least five times larger than an end dimension of a second end of the interconnect, the first end connecting to the micro-scale electrical contact and the second end connecting to the nano-scale electrical contact.


US Patent 7659139 - Selective CNT destruction by irradiation

The fabrication of single walled carbon nanotubes usually results in a mixture of about 1/3 metallic nanotubes and 2/3 semiconducting nanotubes. Several methods exist to sort the metallic from the semiconducting nanotubes such as using ac dielectrophoresis, DNA chromatography, and destruction of metallic nanotubes by electric current. This patent from Sony includes some basic claims for an another method of selective destruction of the metallic or semiconductor nanotubes using laser irradiation. Claims 5 and 9 read:

5. A method for destroying metallic carbon nanotubes comprising irradiating metallic carbon nanotubes with energy beams, wherein the energy beams are laser light.

9. A method for destroying semiconducting carbon nanotubes, the method comprising irradiating with energy beams for destruction of semiconducting carbon nanotubes.


Sunday, February 07, 2010

US Patent 7657447 - Nanomaterial risk evaluation

Business method patents are a controversial area concerned with some non-technological areas such as finance, tax systems, and risk assessment. Usually this is far from the realm of nanotechnology but this patent from Hartford Fire Insurance Company discloses a business method for risk assessment of nanomaterials. Claim 1 reads:

1. A system for determining a level of risk posed by a nanomaterial to an entity, the system comprising:

a memory;

a computerized model stored on the memory; and

a processor configured to:

retrieve from memory data related to the nanomaterial, the retrieved data including physical and chemical characteristics of the nanomaterial;

calculate, using the computerized model, a risk score that is indicative of the level of risk posed by the nanomaterial to the entity based on the retrieved data, wherein the risk score is calculated based at least in part on a quantitative representation of the risks posed by the nanomaterial based on the physical and chemical characteristics of the nanomaterial;

evaluate the insurability of the entity responsive at least in part to the calculated risk score; and

output the results of the evaluation process as an offer or denial for insurance.


US Patent 7657142 - Manufacture of nanoparticle optical fiber

Telecommunication systems often employ glass fibers doped with ions to amplify optical signals. Nanoparticles have been proposed to assist in such doping but have been subject to oxidation which limit their effectiveness. This patent from Alcatel-Lucent discloses a method to avoid such oxidation. Claim 1 reads:

1. A method for manufacturing an optical fiber, comprising:

creating a preform, containing nanoparticles bearing an active element including at least one recess proximate to at least part of the nanoparticles; and

introducing a non-oxidizing gas into the recess, forming the fibers of the preform, thereby limiting the chances that the nanoparticles in the preform will oxidize.


US Patent 7656252 - MEMS resonator with tapered electrode

This patent is from Seiko Epson and teaches a MEMS resonator less susceptible to etching residue and current leakage by providing a tapered contact electrode. Claim 1 reads:

1. A micro-electro-mechanical-system resonator, comprising:

a substrate;

a fixed electrode formed on the substrate; and

a movable electrode, arranged facing the fixed electrode and driven by an electrostatic attracting force or an electrostatic repulsion force that acts on a gap between the fixed electrode and the movable electrode;

wherein the fixed electrode has a tapered surface on a side thereof.


Saturday, February 06, 2010

Memjet® - Microelectromechanical Inkjet Printing

Several years ago I worked as a U.S. Patent Examiner in the area of inkjet printing technology. Most of the companies which filed patent applications in this area are fairly well known such as Canon, Hewlett-Packard, Seiko-Epson, and Xerox. However, there was one company called Silverbrook Research which was not well known but nevertheless was filing patent applications at a similar pace to these larger companies. One of the key features that Silverbrook was focusing on was using microelectromechanical actuators as the ejection mechanism instead of the thermal actuators used by Canon and HP or the piezoelectric actuators used by Seiko-Epson. According to the patent applications this allowed more efficient use of ink, reduced heat generation, and the construction of page wide printheads allowing for digital inkjet printing at speeds much greater than existing inkjet printers and reducing ink costs. In addition, the MEMS designs simplified integration of miniature photoprinters into cameras and other handheld devices. Reading the patent applications of Silverbrook was what first got me interested in MEMS which later lead to my interest in nanotechnology and the creation of this blog.

It is interesting for me to see that a new company called MEMJET® seems to be gaining traction based on Silverbrook's patents and has attracted Len Lauer, the former COO of Qualcomm, to come on board as the companies new CEO. A Youtube video illustrates the speed of some of their printers which puts conventional inkjet printers to shame.

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Thursday, February 04, 2010

US Patent 7655942 - Programmable quantum dot fiber

Wil McCarthy is a science-fiction writer and inventor who has patented a type of programmable matter based on quantum dots. While the enablement of the technology appeared speculative to me it seems to be under development by RavenBrick LLC to create electrochromic effects. Claim 1 reads:

1. A device comprising

a bulk material;

a plurality of artificial atoms distributed within said bulk material in a configuration designed to have a doping effect on said bulk material; and

a plurality of control paths distributed within said bulk material;

wherein each of the plurality of control paths is capable of carrying a respective quantity of energy; and

a subset of the plurality of artificial atoms is operatively coupled with a respective subset of the plurality of control paths, wherein the bulk material further comprises a plurality of fibers and wherein a subset of the plurality of artificial atoms forms a structural part of a subset of the plurality of fibers.


US Patent 7655548 - Nanotube switch for smart power ICs

Smart power grids use software to more effectively distribute energy based on monitored use. This patent from LSI Corporation teaches using nanotube switches to implement a similar smart power system in integrated circuitry. Claim 1 reads:

1. A method, comprising:

coupling a nanotube structure of an integrated circuit to a conductive surface when a command is processed; and

enabling a group of transistors of the integrated circuit based on the coupling the nanotube structure to the conductive surface.


US Patent 7655544 - Self-assembling quantum nanostructures using laser interference

This patent from Utah State University teaches a manufacturing method for growing InAs quantum wires on a GaAs substrate using a laser interference patterning technique. Claim 1 reads:

1. A method of producing self-assembling quantum nanostructures, the method comprising:

depositing epitaxially on a substrate at least one layer of a semiconductor material;

creating at least one laser interference pattern with a laser; and

directing the at least one laser interference pattern onto the substrate thus nanoheating the deposited semiconductor material and the substrate with the laser interference pattern,

wherein the self-assembling quantum nanostructures are produced at the maxima of the laser interference pattern.


Wednesday, February 03, 2010

US Patent 7655479 - Q-dot biomarker for cancer detection

This patent is from H. Lee Moffitt Cancer Center and teaches the use of photo-enhanced nanocrystals to assist in the early detection of ovarian or lung cancer. Claim 1 reads:

1. A luminescent, bio-conjugate for use in the detection of cancerous and precancerous biomarkers in a sample, comprising:

a luminescent semi-conductor nanoparticle;

wherein the nanoparticle is photo-enhanced with electromagnetic energy at between 325 nm and 488 nm, thereby generating electron-hole carrier pairs; and

at least one antibody associated with at least one cancer to be detected.

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US Patent 7655302 - Power transmission with nanotube fiber

In the 1990's a series of basic discoveries regarding carbon nanotubes were made by Richard Smalley's group at William Marsh Rice University. Patents based on this basic research are still being issued to Rice and are being commercialized by Unidym. This latest patent has priority going back to 1997 and is fundamental to power cabling systems based on carbon nanotube fibers. Claim 9 reads:

9. A high voltage power transmission cable

wherein at least one conductor comprises a continuous carbon fiber,

wherein the continuous carbon fiber comprises at least about 106 fullerene nanotubes bundled together in generally parallel orientation.

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US Patent 7653996 - Nanoparticles for crack repair in gas turbine

Turbine engines undergo high thermal and mechanical stress during operation which can produce cracks and limit their life expectancy. This patent from Siemens AG teaches the benefits of using nanoparticles to improve life expectancy such as the low melting point of nanoparticles and penetration into smaller cracks. Claim 1 reads:

1. A method of repairing a crack in a gas turbine component having a base material characterized by an annealing temperature, comprising:

forming a suspension comprising a carrier liquid and nanoparticles which are not soluble in the carrier liquid;

applying the suspension to penetrate into the crack to be repaired;

heating the suspension at a first temperature to evaporate carrier liquid with the nanoparticles being compacted; and

further heating the component to a more elevated temperature below the annealing temperature, wherein the elevated temperature is approximately 50 K above the first temperature and below the melting temperature of the base material, to melt the nanoparticles and form a bond between the nanoparticles and the base material, the further heating at the more elevated temperature having a duration of less than 30 minutes.


USPTO Orders Reexamination of HP's Memristor Patent

The "memristor" has attracted a lot of attention in recent years as a new nanoscale circuit element having properties similar to neural synapses and which is a contender for a new form of non-volatile memory called RRAM. The origins of the memristor go back to a theoretical concept developed by UC Berkeley professor Leon Chua in the 1970s but which lacked a physical material example. In 2008, researchers from HPLabs reported in the journal Nature a solid state version of the memristor capable of being integrated into CMOS electronics processing.

However, it turns out that the material described by HPLabs in the Nature paper (based on a bilayer of oxygen depleted TiO2) was actually patented by researchers from Samsung and not HP. More recently, the one patent that Hewlett-Packard does hold related to the memristor has been ordered for reexamination (Control # 90/009,633) by the USPTO based on earlier work by researchers at the University of Houston. This is bad news for Hewlett-Packard but may be good news for competing companies such as Adesto Technologies, Numonyx, and Unity Semiconductor which are developing alternative materials for RRAM and phase change memory products.

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