Tuesday, April 29, 2008

US Patent 7365003 - Low-k dielectric carbon nanotube interconnects formed in diamond interlayer


This patent from Intel is directed to fabricating low k dielectric carbon nanotube interconnects for high speed electronics. Claim 1 reads:

1. A method of forming a microelectronic structure comprising:

depositing a diamond interlayer dielectric (ILD) on an underlying layer;

etching a trench opening in the ILD;

depositing a liquid crystal host-carbon nanotube solution on the ILD to fill the trench opening; and

removing at least some of the liquid crystal host leaving a carbon nanotube in the trench opening.


US Patent 7364919 - Nanoparticles with carbohydrate ligands


Biopolymers can be broadly classified into three groups - proteins, nucleic acids, and carbohydrates. While proteins and nucleic acids have been studied extensively, carbohydrates have been less well studied due to their complex construction in cells. This patent from Midatech teaches the use of nanoparticles to facilitate examination of these biopolymers. Claim 1 reads:

1. A nanoparticle comprising a core of metal atoms covalently linked to at least 20 ligands, wherein the nanoparticle has more than one species of ligand immobilized thereon and wherein at least one of the species of ligand comprises a carbohydrate group.


Monday, April 28, 2008

US Patent 7362605 - Nanoelectromechanical memory cell


Nantero and a few other companies have explored using nanostructures in mechanical memory cells. Typically these systems use the nanostructure to operate as a mechanical switch but this patent from Ambient Systems examines using nanomechanical structures such as carbon nanotubes to facilitate charge storage as performed in more conventional electronic memory designs. Claim 1 reads:

1. A system comprising:

a base;

a nanometer-scale beam coupled to said base having a first portion that is free-to-move; and

a first charge containment layer coupled to said base in the proximity of said first free-moving portion, wherein said charge containment layer is operable to receive, and store, a first charge profile without moving said nanometer-scale beam and said nanometer-scale beam is not operable to physically touch said first charge containment layer.


US Patent 7362203 - Multi-tap microelectromechanical inductor


Inductors can be vary useful in communication systems however they can be difficult to produce using microfabrication. This patent from Intel teaches a micromechanical inductor structure have a selective disconnect mechanism that reduces parasitic effects. Claim 1 reads:

1. An apparatus, comprising:

an inductor formed on a substrate;

a switching mechanism contacting the inductor to vary inductance of said inductor, said switching mechanism comprising one or more microelectromechanical switch armatures; and

a disconnect mechanism contacting the inductor to reduce parasitic effects of the inductor upon actuation of said switching mechanism.


Thursday, April 24, 2008

US Patent 7361916 - Nanoresonator ion transducer


This patent suggests the use of nanostructure arrays to convert ion or electron radiation into electromagnetic energy and includes some broad patent claims covering this concept. Claim 1 reads:

1. A coupled nano-resonating structure comprising: a plurality of a nano-resonating substructures constructed and adapted to couple energy from a beam of charged particles into said nano-resonating structure and to transmit the coupled energy outside said nano-resonating structure.


US Patent 7361567 - Nanocrystal nonvolatile memory with graded nitrogen content


The use of nanocrystals in some non-volatile memory designs has helped decrease gate leakage. However, electron trapping can be caused due to the nanocrystal layer. This patent from Freescale Semiconductor teaches using a graded nitrogen content to avoid this problem. Claim 1 reads:

1. A method for forming a semiconductor device comprising: providing a semiconductor substrate; forming a first insulating layer over a surface of the semiconductor substrate; forming a layer of nanocrystals over a surface of the first insulating layer; and forming a second insulating layer having a graded nitrogen content over the layer of nanocrystals.


US Patent 7361522 - Method of nanowire growth to compensate for lattice mismatch


This patent from Intel uses vertical nanowire arrays to deals with the problem of lattice mismatch that occurs when different crystalline materials are deposited on a substrate. Claim 1 reads:

1. A method comprising: growing nanowires on a first layer; covering said nanowires with an insulator; planarizing said insulator to form a planarized surface; and resuming the growth of nanowires after planarizing to form a planar second layer over the planarized surface, said first and second layers being lattice-mismatched layers.


US Patent 7361430 - Metal doped CNT/polymer actuator


This patent from the U.S. Dept. of Energy teaches a new type of actuator based on carbon nanotubes having potential as artificial muscle used in MEMS and other devices. Claim 1 reads:

1. An actuator comprising: at least one electrolyte; at least two electric conducting electrodes separated by said at least one electrolyte; at least one electrode of said electric conducting electrodes providing an electromechanical response upon application of an electronic voltage between said at least two electric conducting electrodes; and at least one electrode of said electric conducting electrodes comprising a carbon nanotube-polymer composite doped with a metal.


Wednesday, April 23, 2008

US Patent 7361310 - Dip pen nanolithography of nucleic acids


This is a fairly fundamental patent to Dr.Chad Mirkin's group based on using dip pen nanolithography to transfer nucleic acids to a substrate. Claim 1 reads:

1. A method for generating nanoscale patterns of nucleic acid on a substrate comprising:

modifying a scanning probe microscope tip to have a positive charge and form a modified tip;

coating the modified tip with an ink composition comprising solvent, nucleic acid and inorganic salt;

positioning the modified and coated scanning probe microscopic tip relative to a substrate so that the tip and substrate approach each other at a relative humidity sufficiently high so that nucleic acid is transferred from the tip to the substrate to form a stable nanoscale pattern on the substrate.

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US Patent 7361204 - Microparticle to nanoparticle conversion using focused irradiation


This patent from the U. of Florida includes some fairly broad claims toward vaporizing microparticles to generate nanoparticles. Claim 1 reads:

1. A method of generating nanoparticles from a single microparticle, comprising the steps of:

dispensing a target stream of microparticles of material from a source;

focusing a light source onto the target stream; heating the target stream with the light source;

generating flux-specific bursts of nanoparticles from the heated target stream; and

varying at least one of a size of the microparticle and a repetition rate of the light source to control the flux of nanoparticles generated.

Some prior art which was not considered during examination and which could be relevant includes Cai et al. "Generation of metal nanoparticles by laser ablation of microspheres ".


US Patent 7360851 - Feedback adjustment for nanoimprint lithography density control


Nanoimprint lithography is a method of transferring nanoscale patterns onto a variety of substrates. This patent from KLA-Tencor teaches a particular method of nanoimprint lithography based on liquid transfer in which the density of the liquid being transferred is monitored for feedback regulation. Claim 1 reads:

1. A method for control of spreading of liquid droplets, comprising:

depositing an initial pattern of drops of a liquid on a first surface;

bringing a second surface into sufficient contact with at least a portion of the initial pattern of drops on the first surface that the liquid begins to spread; capturing one or more digital images of the liquid after it begins to spread;

performing a digital analysis of the one or more images to determine whether one or more portions of the initial pattern of drops require more liquid; and

adjusting a subsequent pattern of drops of liquid based on the digital analysis of the two or more images.


US Patent 7360461 - CNT layer for air transport tubing


Some air sampling tubes suffer from the problems of absorption or desorption or volatile organic compounds (VOCs) leading to inaccurate senor results. This patent from Aircuity, Inc. teaches using carbon nanotubes to help prevent these problems. Claim 1 reads:

1. An air sampling system, comprising:

a sensor suite that measures at least one characteristic of an air sample;

air intake valves for switching air samples; and

tubing coupled to the air intake valves and a plurality of termination points from which air samples are obtained and transported via the tubing to the sensor suite,

wherein at least a portion of the tubing includes an electrically conductive inner layer having carbon nanotubes in a host material, wherein the combination of the host material and the carbon nanotubes minimizes absorption, desorption and off-gassing for the air samples.

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Monday, April 21, 2008

US Patent 7359888 - Nanowire crossbar neural net


Conventionally artificial intelligence is based on software configured for general purpose microprocessors or as application specific integrated circuitry. However, since the underlying materials used for microprocessors and ASICs are based on silicon or other semiconducting crystalline structures there are limits to the flexibility of A.I. designs in the conventional approaches. Electronics based on molecular or amorphous nanomaterials which are more capable of reconfigurability may not be subject to such constraints. This is a fairly interesting patent from Hewlett Packard which teaches one way of implementing such a configurable A.I. using a neural net formed from nanowire crossbars. Claim 1 reads:

1. A nanoscale neural network circuit comprising: input nanowire signal lines; output nanowire signal lines; and at least one layer of neural network nodes programmed into a molecular-junction-nanowire crossbar.


US Patent 7359694 - CNT RF mixer


This patent from Northrop Grumman Corporation teaches forming pn diodes using carbon nanotubes and arranging these nanotube diodes in a quad configuration commonly seen in full wave rectifier circuitry. The benefit of the circuit is taught to be found in high frequency (>terahertz) mixers. Claim 1 reads:

1. A diode quad comprising:

a substrate;

first and second electrodes formed on the surface of said substrate and separated by a first gap;

fourth and third electrodes formed on the surface of the substrate and separated by a second gap, a portion of said fourth and said third electrodes being formed in said first gap;

a first p-n junction carbon nanotube diode connecting said first electrode with said third electrode;

a second p-n junction carbon nanotube diode connecting said first electrode with said fourth electrode;

a third p-n junction carbon nanotube diode connecting said second electrode with said third electrode; and

a fourth p-n junction carbon nanotube diode connecting said second electrode with said fourth electrode.


Thursday, April 17, 2008

US Patent 7358822 - MEMS oscillator using temperature modulation control


One common method to actuate MEMS cantilevers and other structures is to include a thermal heater as part of the MEMS structure and use a bi-layer of material having differing thermal expansion coefficients which causes bending upon heating. However, for applications in MEMS oscillators a proximal heater can have adverse effects on the resonance frequency. This patent from Cornell teaches using a remote laser for the actuation to avoid such problems. Claim 1 reads:

1. A method comprising:

modulating temperature of a portion of a device having a microelectromechanical oscillator formed from a device layer supported by a support layer; and

wherein temperature modulation creates oscillation of the oscillator; and

wherein the oscillator is spaced apart from the portion of the device having its temperature modulated.


US Patent 7358524 - Electrolyte doping of nanowire junctions


Most semiconductor devices require doping in order to create diodes, transistors and other active electronic components. Usually such doping includes both n-type doping, which adds material to the semiconductor to create an excess of electrons usable for charge transport, and p-type doping, which adds material to the semiconductor to create a deficit of electrons so that electron "holes" are usable for charge transport.

However, for nanowires performing both p and n type doping can be problematic. This patent from Samsung teaches an interesting solution in which aligned nanowires are formed to connect two electrodes and an electrolyte is filled between the spaces. Application of a voltage dissociates the electrolyte into anions (negative charged ions) and cations (positively charged ions) so as to form pn junction nanowires. Claim 1 reads:

1. A nanowire device comprising: a substrate; a first electrode layer formed on the substrate; a second electrode layer facing to the first electrode layer; a plurality of nanowires interposed at a predetermined interval between the first electrode layer and the second electrode layer to connect the same; and an electrolyte containing an electrolytic salt filling spaces between the nanowires.


Wednesday, April 16, 2008

US Patent 7357906 - Single walled CNT separation


This patent originating from research by Richard Smalley's group at Rice University has priority going back to Aug. 8, 1996 and seems fairly basic to single walled carbon nanotube separation by type. Claim 1 reads:

1. A method comprising: a) providing a mixture of single-wall carbon nanotubes; b) derivatizing the single-wall carbon nanotubes; c) dispersing the single-wall carbon nanotubes; and d) fractionating the mixture by a characteristic selected from the group consisting of lengths, diameters, helicities and combinations thereof.

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US Patent 7357691 - Flat CNT field emission array


This patent discloses an interesting method for making carbon nanotube vertical array field emitters. Usually the nanotubes are grown from a cathode electrode but in this method the cathode electrode is formed on top of the nanotubes after growth and the supporting substrate from which the nanotubes are grown is removed. This method provides uniform length nanotube arrays with a flat surface. Claim 1 reads:

1. A method for making a carbon nanotube-based field emission device comprising steps of:

providing a substrate having a flat surface which has a variation in flatness of less than 1 micron;

forming a carbon nanotube array extending from a selected area of the surface of the substrate by a chemical vapor deposition process, the carbon nanotube array having a flat bottom surface corresponding to the flat surface of the substrate; forming a cathode electrode on a top of the carbon nanotube array; and

removing the substrate so as to expose the flat bottom surface of the carbon nanotube array so that the flat bottom surface of the carbon nanotube array is thereby configured for acting as an electron emitting surface of the carbon nanotube-based field emission device.

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Tuesday, April 15, 2008

US Patent 7357690 - Alignment of CNTs using grooves


This patent from Canon (priority Nov. 19, 2003) teaches an alignment method of carbon nanotubes or other high aspect ratio structures using a grooved substrate. Claim 1 reads:

1. A method for aligning needle-like structures, comprising: a providing step of providing a substrate having a surface and at least one groove defined therein; and an alignment step of placing the needle-like structures dispersed in a disperse medium in the groove so that the needle-like structures align along a length of the groove in parallel with the surface of the substrate.

However, some prior art may have been overlooked such as US Patent 6,872,645 (see for example column 16, lines 20-56) with priority going back to Sept. 10, 2002.


US Patent 7357018 - Nanowire FET probe


In recent years atomic force microscopes have begun using carbon nanotubes as tips in order to achieve inspection of trench structures using the high aspect ratio of CNTs. This patent from Agilent teaches a similar modification of AFM tips which uses a nanowire as the tip and functionalizing the nanowire so that it acts as a gate of a chem-FET. Claim 1 reads:

1. A method for performing a measurement inside a specimen, the method comprising:

providing nanoscale FET probe comprising a cantilever element and a nanowire extending from the cantilever element, the nanowire electrically connected to the cantilever element at at least one of the ends of the nanowire;

coating the nanowire along at least part of the length thereof with molecules of a capture agent;

moving the cantilever element to insert the nanowire into the specimen; and

monitoring an electrical property of the nanoscale FET probe to detect binding events between the capture agent molecules and an analyte of interest inside the specimen.


Monday, April 14, 2008

US Patent 7355704 - SERS using nanoparticles in ultrathin polymer layer


Surface Enhanced Raman Spectroscopy (SERS) is a technique using laser reflection from rough metal surfaces to detect and analyze individual molecules. Metallic nanoparticles are often used to achieve the rough surface and this patent from Solaris Nanosciences teaches the inclusion of an ultrathin (0.5 nm - 10 nm) polymer layer surrounding the nanoparticles to further improve the SERS effect. Claim 1 reads:

1. A film for surface enhanced Raman scattering comprising: A polymeric layer; and A metallic nanoparticle having a cross-section and being embedded in the polymeric layer, wherein the polymeric layer has a thickness less than a largest straight line through the cross-section of said metallic nanoparticle.


US Patent 7355334 - Crosslinked CNT electron emitter


This patent from Fuji Xerox claims crosslinking of carbon nanotubes in forming an electron emitter to increase mechanical and electrical stability. Claim 1 reads:

1. An electron beam generator device comprising: a base body having a conductive surface; and an electron-emission electrode having a carbon nanotube structure on the conductive surface of the base body, wherein the carbon nanotube structure constitutes a network structure which has plural carbon nanotubes and a crosslinked part including a chemical bond of plural functional groups, the chemical bond at least connecting one end of one of the carbon nanotubes to another one of the carbon nanotubes.

However, US Patent 6,057,637 was not considered during prosecution and may by relevant as teaching the use of an epoxy matrix and crosslinking carbon based nanotubes for a field emission device (see column 5, line 66 - column 6, line 7).


Thursday, April 10, 2008

US Patent 7355329 - CNT field emission lamp bulb


This patent teaches a light bulb based on field emission from carbon nanotubes formed on the outer surface of a base of the lamp head. Claim 1 reads:

1. A field emission lamp comprising:

a bulb being vacuum sealed and having an inner surface;

a lamp head mated with the bulb; an electron emitting cathode positioned in the bulb, wherein the electron emitting cathode comprises a plurality of electron emitters, and a base body having an outer surface, the base body is comprised of metallic material, and the electron emitters are carbon nanotubes and are formed on the outer surface of the base body;

an anode layer formed on the inner surface of the bulb; a fluorescence layer formed on the anode layer; an anode electrode located at the lamp head and electrically connected with the anode layer; and

a cathode electrode located at the lamp head and electrically connected with the electron emitting cathode.

One relevant patent that wasn't considered during prosecution is US Patent 6573643 which teaches a field emission light source using a carbon coating which includes carbon nanotubes (see column 9, lines 20-30).

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US Patent 7355182 - Multispectral camera using CNT detector for mid-infrared


Infrared cameras are used for night vision and medical diagnostics applications but can suffer from thermal noise which requires cryogenic cooling. This patent teaches a multi-spectral camera that avoids the need for such cooling and which uses carbon nanotubes as a detection element of mid-infrared frequencies. Claim 59 reads:

59. A multi-spectral camera, comprising: a long-infrared charge-coupled device; a mid-infrared detector array; and a control device that synchronizes operation of the charge-coupled device and the detector array; wherein the mid-infrared detector array includes carbon nanotubes; and wherein the carbon nanotubes are tuned-bandgap carbon nanotubes.


Wednesday, April 09, 2008

US Patent 7355216 - Nanofluidics using non-carbon nanotube


Nanofluidics uses structures of nanometer dimensions to analyze fluids on a molecular level. One of the key elements for nanofluidic devices is a fluid transport structure with a diameter on the scale of nanometers. This patent from the University of California notes that carbon based nanotubes are largely hydrophobic and unsuitable for nanofluidic applications and teaches the fabrication of alternative non-carbon nanotubes as fluidic transport elements.

1. A fluidic nanotube, comprising: a tubular member having first and second ends, and an inner bore between said first and second ends; said tubular member having a non-porous inner wall; said tubular member comprising a non-carbon, hydrophilic material; wherein said nanotube comprises a single crystalline structure.


US Patent 7354877 - Superconducting CNT Faraday Cage


A Faraday cage is a conductive enclosure which protects electronics from external electromagnetic interference. This patent from Lockheed Martin teaches a Faraday Cage garment formed of superconducting carbon nanotubes. Claim 1 reads:

1. A garment made of fabric, wherein said fabric comprises: a first layer of yarns woven to form the fabric wherein said yarns comprise at least one carbon nanotube fiber and wherein said carbon nanotube fiber comprise single-walled carbon nanotubes and/or multi-walled carbon nanotubes; and at least one additional layer of yarns woven together, wherein said first layer comprises yarns of superconductive carbon nanotube fibers that form a Faraday cage and wherein said at least one additional layer of yarns woven together comprise insulating carbon nanotube fibers.


Tuesday, April 08, 2008

US Patent 7354871 - Nanodot formed in nanowire


This patent from Samsung teaches a solid-liquid-solid (SLS) fabrication method for growing silicon nanowires diffused from a substrate and coupled to gold nanoparticles. Claim 1 reads:

1. A nanowire, comprising: a plurality of metal nanodots uniformly disposed therein; and a core portion, wherein each of the plurality of metal nanodots is coupled to the core portion.


US Patent 7354788 - Scanning probe memory formed by dual wafer manufacture


Scanning probe microscopy techniques have allowed for nanoscale inspection and characterization in the past decades and have gradually been applied to spin-off applications in nano-lithography and high density memory such as IBM's use of 1,024 probe tips for a high density memory. This patent from Intel is along similar lines and teaches segmenting CMOS circuitry from the MEMS-based scanning probe structures to provide for easier fabrication. Claim 1 reads:

1. A method comprising: fabricating microelectromechanical (MEMS) structures of a Seek and Scan Probe (SSP) memory device on a first wafer; and fabricating CMOS and memory medium components of the SSP memory device on a second wafer.


Thursday, April 03, 2008

US Patent 7352608 - Vibrational nanomechanical memory


There is a growing interest in mechanical memory and computing devices as discussed in theis Computerworld article. This patent from Boston University teaches one variation of nanomechanical memory using vibration states stored in a nanoscale bridge. Claim 1 reads:

1. A nanoscale mechanical memory element comprising: a bridge element between first and second supports; means for vibrationally exciting said bridge at a first frequency representative of a first state; means for vibrationally exciting said bridge at a second frequency lower than said first frequency representative of a second state; and means for sensing the state of said bridge.


US Patent 7352559 - CNT field emitter using conduction enhancing gas medium


This patent has priority going back to 3/21/2002 and teaches a carbon nanotube field emission device using a gas medium such as argon, neon, xenon, or radon for enhanced lighting. Claim 1 reads:

1. A carbon nanotube electrical device comprising: a) a cathode coated with carbon nanotubes and configured for emitting electrons; b) an anode placed in an electrically conductive relationship with the cathode, such that there is a space between the cathode and the anode; and c) a gas medium placed in the space which participates in the transfer of electrons across the space.

However, some relevant prior art may have been overlooked such as Choi et al. "Fully sealed, high-brightness carbon-nanotube field-emission display" (see Fig. 2a and note that partial pressure of Argon gas is used). Alternatively, see US Patent 6,965,199 with priority from 3/27/2001 and explicitly noting the benefits of inert gases such as argon in carbon nanotube gas discharge tubes (note Fig. 5).

Wednesday, April 02, 2008

US Patent 7352007 - Phosphorescent nanotube memory


This patent from Micron Tech. teaches a new type of optical memory using nanotubes which is proposed as a potential replacement for DRAM. Claim 1 reads:

1. A memory die, comprising: a semiconductor substrate supporting a memory cell array, the memory cell array comprising: a plurality of memory cells, each memory cell further comprising: a pixel capable of emitting and receiving light, and a material localized over the pixel, the material having nanotubes formed therein, the nanotubes having phosphorescent material, wherein the phosphorescent material receives light from and emits light to the pixel; and circuitry connecting the plurality of memory cells to the semiconductor substrate.


US Patent 7351907 - Photovoltaic nanoparticles for powering flexible display


This patent from Konarka Technologies teaches an interesting solar powered flexible display device taught to be useful for store shelfs of supermarkets. Claim 1 reads:

1. A flexible display apparatus comprising: a flexible base; at least one flexible photovoltaic cell disposed upon the flexible base; and a display element disposed upon the flexible base and operably connected to the at least one flexible photovoltaic cell, wherein the at least one flexible photovoltaic cell comprises a photosensitized nanoparticle material and a polymeric linking that convalently interconnects the photosensitized nanoparticle material.


Tuesday, April 01, 2008

US Patent 7351601 - Fabrication of nanocavity laser


This method of solid state laser fabrication teaches optically trapping a quantum dot bead in the laser cavity to provide optical gain for the laser. Claim 1 reads:

1. A method of fabricating a nanocavity laser, said method comprising:

pumping a laser cavity that supports an optical mode having an optical field concentrated in a region of said laser cavity; and

optically trapping a light emitter in said region of said laser cavity, the light emitter configured to provide optical gain for said laser cavity.


US Patent 7350397 - Porous cavity for nanoparticle detection


This patent teaches a device for detecting carbon nanoparticles in exhaust gas using a porous insulating film such as porous aluminum oxide. Claim 1 reads:

1. Device for detecting the amount or concentration of solid particles of nanometric or sub-micrometric size in a gas medium, in particular particulate matter in the exhaust gas of an internal combustion engine, comprising:

a structure for the deposit of solid particles present in the gas medium, at least a first and a second electrode associated to said structure, and

means for measuring an electric quantity between the first and second electrodes, wherein a plurality of cavities is defined in said structure, which act as collectors of solid particles present in the gas medium, the structure being arranged so as to enable collection of said particles inside said cavities, and wherein said structure comprises a porous body made of an electrically insulating material, the pores of said body constituting at least part of said cavities.