Friday, December 30, 2011

Top Ten Nanotechnology Patents of 2011

Here is a list of the U.S. nanotechnology patents issued over the past year that appear to me to be the most valuable or interesting:

#10 - US Patent 7921384 - Nanoscale FPGA for nanorobotics (Neal Soloman)

I am dubious of the enablement of most "nanorobot" related patents but they can be interesting reading even if they are nonsense. 

#9 - US Patent 8062407 - Nano-manufacture using household microwave (Northwest Missouri State University )

This patent warrants the garage inventor of the year award for developing a cheap way to synthesize silver nanoparticles.

#8 - US Patent 8057776  - Carbon nanotube manufacture from microalgae (United Arab Emirates University)

This patent represents the first teaching (to my knowledge) of using biomaterial to create carbon nanotubes. I am not sure how useful this will be but the inventor deserves an A+ for creativity.

 #7 - US Patent 7922795 - Nanoscale semiconductor membrane (University of Rochester)

This patent includes some basic claims for semiconductor membranes which may be critical to the development of hydrogen-permeable membranes for fuel cells and pressure sensors.

#6 - US Patent 8060217 - Nanowire neural interface (Industry-Academic Cooperation Foundation)

Neural interfaces are an emerging technology but are limited by the damage done due to electrical signals applied to nerve cells. The teachings of this patent may contribute to a solution which can open up a whole new industry.

#5 - US Patent 8068624 - CNT thermoacoustic sound generator (Foxconn)

This is one of numerous basic patents issued this year to Hon Hai Precision (Foxconn) covering a newly discovered application of carbon nanotubes which may represent one of the most significant developments in the area of sound production in the last 100 years enabling sound without magnetic fields or vibration.

#4 - US Patent 8063448 - Memresistor FinFET (Infineon Technologies)

Two of the leading trends in semiconductor electronics are the use of multi-gate transistor structures and the use of thin film memory resistor materials for memory cells (e.g. phase change memory, ReRAM). this patent includes some basic claims combining these concepts.

#3 - US Patent 8053782 - Graphene phototransistor (IBM)

The 2010 Nobel Prize went to research in the new nanomaterial graphene and inventions based on graphene are in their infancy. This patent includes some basic claims for graphene used in photodetectors.

#2 - US Patent 7902541 - Strained nanowire FET (IBM)

Semiconductor nanowire technology is becoming more sophisticated and IBM is leading the way in manufacturing these materials into future generation high-speed transistors.

#1 - US Patent 8066831 - Nanoenergetic power generation (The Curators of the University of Missouri)

New solutions for energy production are perhaps the key applications for nanomaterials. This patent from the Gangopadhyay Research Group represents one of the most innovative techniques I have yet heard of for the use of nanomaterials in power generation for portable devices.


Wednesday, December 28, 2011

US Patent 8086079 - Aligned nanotube array responsive to electromagnetic energy

Back in 1997 inventor Robert Crowley recognized several uses of carbon nanotubes as an optical antenna and filed several basic patents based on these ideas. This is the latest of his patents including some broad claims covering carbon nanotubes responding to electromagnetic energy. It may be noteworthy that this patent and the parent patents were recently featured in a patent auction (link). Claim 1 reads:  

1. An electrical device for the utilization of electromagnetic energy, the device comprising:

a substrate; and

an aligned array of electromagnetic energy responsive nanotubes supported by and extending through the substrate, arranged to respond to electromagnetic energy.

US Patent 8084927 - CNT twisted wire electron emitter

There have been a wide variety of patents issued over the past decade for carbon nanotubes exhibiting electron emission for applications in flat panel displays, lighting, and sensors. Most of these patents are based on field emission effects of the carbon nanotubes but this latest patent from Foxconn teaches a new type of nanotube electron emitter based on thermionic emission which can improve the mechanical durability and lifespan of devices such as gas lasers, arc-welders, plasma-cutters, electron microscopes, and x-ray generators. Claim 1 reads:

1. A thermal electron emitter comprising:

at least one carbon nanotube twisted wire comprising a plurality of carbon nanotubes; and

a plurality of electron emission particles having a work function lower than a work function of the carbon nanotubes,

wherein at least portions of the plurality of electron emission particles are substantially uniformly dispersed within the twisted wire.

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US Patent 8084140 - Silver nanoplatelets

This patent is from Clarkson University and teaches a method of producing a new variation of silver nanoparticle with applications in electromagnetic shielding. Claim 1 reads:

1. A metallic nano-platelet comprising between 90% and 99.99% silver by weight; and between 0.01% and 10% palladium by weight.


US Patent 8084011 - Method of increasing thickness of carbon nanotube arrays

Most of the techniques used to mass produce carbon nanotube arrays involve chemical vapor deposition (CVD). However, there is a limit to the thickness of the nanotubes which can be grown due to the effect of reaction byproduct gas and an excess raw material gas during CVD growth. This patent from the Denso Corporation of Japan teaches a growth method to deal with this problem and grow nanotubes with a greater thickness to improve the efficiency of mass production. Claim 1 reads:

1. A method of manufacturing a vertically aligned carbon nanotube by using a chemical vapor deposition method, comprising the steps in the order named of:

providing a substrate and a catalyst to be fixed on the substrate, in a reaction chamber;

heating the catalyst fixed on the substrate in the reaction chamber;

filling-up the reaction chamber with a raw material gas serving as a carbon source, thereby synthesizing vertically aligned carbon nanotubes in the reaction chamber;

after a film thickness of vertically aligned carbon nanotubes synthesized on the substrate has increased by at least a measurable amount, exhausting a reaction byproduct gas from the reaction chamber; and

repeating the filling-up step and the exhausting step until a film of vertically aligned carbon nanotubes having a desired film thickness is manufactured.


Thursday, December 22, 2011

US Patent 8081287 - LCD with CNT heater

The switching voltage of LCDs is sensitive to temperature and a heating layer is used to maintain a consistent temperature. This patent from Hon Hai Precision includes basic claims for using carbon nanotubes in the heating layer to improve efficiency. Claim 1 reads:

1. A liquid crystal display comprising:

at least one heating element located on at least one of a first substrate and a second substrate comprising at least one carbon nanotube structure.

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US Patent 8080487 - Anti-ballistic nanotube fabric

Antiballistic fabrics such as Kevlar are useful for creating bulletproof armor but exposure to continuous heat can reduce their effectiveness. This patent from Lockheed Martin teaches using carbon nanotubes in bulletproof fabrics with improved thermal characteristics and lighter weight. Claim 1 reads:

1. An antiballistic fabric comprising:

at least one layer of fabric, wherein at least one layer of fabric comprises fibers, yarns or tow; and

nanotubes synthesized within interstices between the fibers of at least one layer of fabric and that are entangled with and anchored to the fibers,

wherein the nanotubes enhance the antiballistic properties of at least one layer of fabric and wherein the nanotubes synthesized within interstices between fibers form a Faraday cage.


US Patent 8080441 - Forming graphene sheets from photoresist

Photoresists are materials having light sensitive properties used in patterning semiconductor and wiring patterns on a substrate. This patent from Cree, Inc. includes some basic claims to a method of forming graphene sheets on a substrate from a photoresist layer. Claim 1 reads:

1. A method of forming a polygonal carbon layer, the method comprising:

providing a photoresist layer on a substrate; and

energizing the photoresist layer until the photoresist layer forms graphene or a graphene-like sheet.


Tuesday, December 20, 2011

US Patent 8080405 - Core/shell nanocrystal probes

This patent from the Regents of the University of California has priority going back to 1997 and includes some basic claims for core/shell semiconductor nanocrystals. Claim 1 reads:

1. A semiconductor nanocrystal composition, comprising:

a) a core comprising a first semiconductor material;

b) a core-overcoating shell comprising a second semiconductor material, wherein the core and the core-overcoating shell form a core/shell nanocrystal; and

c) an encapsulating net surrounding the core/shell nanocrystal.


US Patent 8080278 - Cold gas spraying of nanoparticles

Thermal spraying is used to deposit and adhere nanoparticle films on substrates but is only practical for types of nanoparticles having a high temperature stability. This patent from Siemens teaches a cold gas spraying method enabling the deposition of nanoparticles having low temperature stability. Claim 1 reads:

1. A cold gas spraying method, comprising:

providing a substrate to be coated;

directing a cold gas jet at the substrate to be coated; and

forming the coating upon the substrate by the addition of microencapsulated agglomerates of nanoparticles via the cold gas jet.


US Patent 8080183 - Nanoparticle assembly with molecular springs

This patent from Ohio University teaches a nanoparticle assembly used as a luminescent tag with improved signal-to-noise ratio compared to semiconductor nanocrystals (i.e. quantum dots). Claim 1 reads:

1. A dynamic nanoparticle structure comprising:

a first nanoparticle;

a second nanoparticle; and

a molecular spring, and wherein:

the first nanoparticle is connected to the second nanoparticle by the molecular spring;

the first nanoparticle comprises a metallic nanoparticle;

the second nanoparticle comprises a semiconducting nanoparticle, the semiconducting nanoparticle selected from the group consisting of Cd, CdS, CdSe, CdTe, Si, ZnO and combinations thereof; and

the molecular spring comprises PEG and derivatives thereof.


Thursday, December 15, 2011

US Patent 8076836 - CNT light source

This patent from Hon Hai Precision (Foxconn) is based on the finding that carbon nanotube films formed with varying density emit polarized light when a current is applied. Claim 7 reads:

7. A light source comprising:

a carbon nanotube film comprising a plurality of first areas and a plurality of second areas, the first areas and the second areas each comprising a plurality of successively oriented carbon nanotubes joined end-to-end by Van der Waals attractive force therebetween, wherein the first areas and the second areas have different densities of carbon nanotubes; and

two electrodes electrically connected to the carbon nanotube film.

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US Patent 8076829 - CNT artificial muscles

This patent from Hon Hai Precision (Foxconn) teaches a carbon nanotube composite forming an actuator requiring less power to operate than conventional actuating composites. Claim 1 reads:

1. An electrostrictive composite comprising:

a flexible polymer matrix in a sheet structure form; and

a plurality of one dimensional conductive materials dispersed in the flexible polymer matrix, the one dimensional conductive materials-cooperatively forming an electrically conductive structure in the flexible polymer matrix,

wherein the one dimensional conductive materials are carbon nanotubes oriented substantially along a preferred orientation and joined end to end by van der Waals attractive force.

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US Patent 8076662 - Nanostructured oxide memresistor

Over the past few years Samsung (US Patent 7417271) and Sharp (US Patent 7796416) have been developing memory resistors based on metal oxide materials. This latest patent from Harvard teaches another variation of memory resistors including nanodot structures. Claim 7 reads:

7. An oxide nanostructure, comprising:

a substrate;

a nanoscale oxide thin film deposited on the substrate, the nanoscale oxide thin film having a conductance that can be changed by an electric field transmitted across the film; and

one or more nanodots deposited on the nanoscale oxide thin film;

wherein the nanodots are adapted, when an electric field is applied thereto, to transmit the electric field across the nanoscale thin film so that the conductance of the thin film is changed and a metal-insulator transition is induced across the thin film.


Wednesday, December 14, 2011

US Patent 8076583 - CNT light-transmitting electric conductor

This patent from Sony teaches a variation of transparent electrodes based on carbon nanotubes having an improved affinity with light-transmitting supports. Claim 1 reads:

1. A light-transmitting electric conductor comprising, on a surface of a light-transmitting support:

a conductive material in which a multiplicity of carbon nanolinear structures are accumulated in two dimensions while making partial contact with each other,

wherein said conductive material is a light-transmitting conductive material composed of said carbon nanolinear structures, and direct bonds are formed between said surface of said light-transmitting support and said carbon nanolinear structures making contact with said surface without the carbon nanolinear structures being buried in the light-transmitting support, and between said carbon nanolinear structures making contact with each other.


US Patent 8075950 - Process of preparing graphene nanoshell

Graphene usually refers to the planar form of a carbon lattice having a honeycomb atomic arrangement. This patent from Samsung teaches a way to form 3D shells of graphene which may have similar properties as carbon nanotubes or fullerene. Claim 1 reads:

1. A process of preparing a graphene shell, the process comprising:

forming a graphitizing catalyst in a three-dimensional form;

coating a polymer on the graphitizing catalyst;

heat-treating the polymer coated on the graphitizing catalyst in an inert or reductive atmosphere to form a graphene shell; and

further comprising separating the graphene shell by removing the graphitizing catalyst with an acid-treatment after the heat-treatment.


US Patent 8075864 - Preparing large area graphene sheets

This patent from Samsung teaches a way to manufacture graphene sheets having a wide area which may assist future mass production of high speed nanoelectronics. Claim 1 reads:

1. A process of preparing a graphene sheet, the process comprising:

forming a graphitizing catalyst in the form of a sheet;

forming a sheet of polymer on the graphitizing catalyst; and

heat-treating the polymer on the graphitizing catalyst in an inert or reductive atmosphere to form a graphene sheet,

wherein a width and a length of the graphene sheet are each about 1 millimeter or greater.


Tuesday, December 13, 2011

US Patent 8075863 - Growing nanowires in a microfluidic environment

Typically nanowires and nanotubes are grown in reaction chambers having sizes ranging from centimeters to meters in which localized control of growth conditions is difficult. This patent from M.I.T. teaches a method of growing nanostructures in a microfluidic environment to provide localized control of growth conditions. Claim 1 reads:

1. A method of growing an elongated nanostructure, comprising:

causing a nanoparticle catalyst to float in a microfluidic channel by applying a magnetic or an electromagnetic field;

flowing a fluid in a first direction in the microfluidic channel;

initiating growth of an elongated nanostructure from the nanoparticle catalyst while the catalyst is floating in the microfluidic channel; and

continuing growth of the elongated nanostructure substantially in the first direction in the microfluidic channel.


US Patent 8075794 - Magnetic graphite nanoplatelets

This patent from Teledyne Scientific and Imaging teaches a magnetic nanomaterial based on graphite in which the thermal conductivity can be adjusted in a particular direction or plane by controlling the orientation of the magnetic graphitic material. Claim 1 reads: 

1. A magnetic graphite nanoplatelet compound, comprising:

a plurality of expanded graphite nanoplatelets having a random orientation; and

magnetic metal particles dispersed among, and adhered to, the plurality of graphite nanoplatelets.


US Patent 8075792 - Metal nanoparticle etchant for silicon surfaces

One way to improve the efficiency of silicon solar cells is to minimize the reflectivity of silicon surfaces. This patent from the Alliance for Sustainable Energy teaches a way to use gold or silver nanoparticles in an etching solution to roughen silicon surfaces and improve the efficiency of silicon solar cells. Claim 1 reads:

1. A method of texturing a silicon surface, comprising:

positioning a substrate with a silicon surface in a vessel;

filling the vessel with a volume of an etching solution that covers the silicon surface of the substrate, wherein the etching solution comprises a catalytic nanomaterial and a oxidant-etchant solution comprising an etching agent and a silicon oxidizing agent; and

etching the silicon surface by agitating the etching solution in the vessel.


US Patent 8075524 - Syringe set with CNT heater

For many medical procedures injected fluid needs to be maintained near body temperature. This patent from Hon Hai Precision (Foxconn) teaches using carbon nanotube material as the heater in a syringe set. Claim 1 reads:

1. A syringe set comprising:

a syringe; and

a heating device comprising:

a heating module in thermal engagement with the syringe, the heating module comprising a heating element, a first electrode and a second electrode, wherein the heating element comprises a plurality of carbon nanotubes forming at least one electrically conductive path between the first electrode and the second electrode, and the first electrode and the second electrode electrically connect with the carbon nanotubes; and

a body supporting the heating module;

wherein the at least one electrically conductive path is adapted to convert a current into a heat and transfer the heat.

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Thursday, December 08, 2011

US Patent 8072226 - Electrode structure for nanosensor

This patent teaches a surrounding electrode configuration for a nanosensor which may simplify manufacture. Claim 1 reads:

1. A sensor comprising:

a substrate;

a first electrode disposed on the substrate;

a second electrode disposed on the substrate, the second electrode being spaced apart from the first electrode and circumscribing at least all sides along at least one axis of the first electrode; and

at least one nanostructure contacting the first electrode and the second electrode, the at least one nanostructure configured to vary an electrical characteristic according to an object to be sensed;

wherein the object to be sensed comprises a solution, a liquid, a gas, a molecule, a protein, a virus, a marker, an acid, an ion, an impurity, an electromagnetic radiation, or a particle, and wherein the electrical characteristic comprises a voltage, a current, a resistance or a conductance.


US Patent 8072039 - Quantum dot energy conversion film

This patent from Samsung teaches how thin films including quantum dots can be used to convert incoming photons to an energy level capable of being converted to electrical energy. Claim 1 reads:

1. A solar cell module comprising:

a solar cell generating an electric current upon absorbing light, and at least one layer comprising a quantum dot and having a thickness of about 20 nanometers to about 10 micrometers,

wherein the layer converts an incident light to a lower energy light on the entire light incident surface of the solar cell.


US Patent 8071972 - Silicon memresistor nanowire crossbar array

In the past decade there have been several proposals for using chalcogenide or metal oxide materials in crossbar arrays to construct a form a high density non-volatile memory called RRAM. This patent from the University of Michigan teaches a new variation of RRAM based on amorphous silicon pillars having nanoscale dimensions.Claim 1 reads:

1. A crossbar memory array, comprising:

a first array of nanowires of a first material;

a second array of nanowires of a different second material oriented at an angle with the first array; and

a plurality of non-crystalline silicon nanostructures, each intersection of the first array and the second array including one of the non-crystalline silicon nanostructures disposed between a nanowire of the first material and a nanowire of the second material to form a resistive memory cell;

wherein at least one of the plurality of non-crystalline silicon nanostructures is a nanoscale pillar providing a contact point between the first and second arrays at exactly one intersection.


Tuesday, December 06, 2011

US Patent 8071359 - Core/shell nanocrystal bioprobes

This patent from the Regents of the University of California has priority going back to 1997 and includes some basic claims to core/shell nanocrystals used in bioprobes. Claim 1 reads:

1. A luminescent semiconductor nanocrystal composition, comprising:

a semiconductor core comprising a first semiconductor material;

a core-overcoating shell comprising a second semiconductor material which is different from the first semiconductor material, wherein the core and core-overcoating shell form a core/shell nanocrystal; and

a polymer.


US Patent 8070988 - Nano-carbon hybrid structures

This patent teaches a modified example of carbon nanotube and nanodiamond suspension to improve the mechanical properties of nanocomposites. Claim 1 reads:

1. A stable colloidal suspension of carbon-based nanomaterials in a solvent, comprising:

a stable colloidal suspension of nanodiamond particles having at least one additional carbon-based nanomaterials disbursed and agitated into the solvent to produce said suspension.


US Patent 8069688 - Nanostructured gemstones

This patent from the California Institute of Technology includes some broad claims for gemstones having improved brilliance based on the etching of non-periodic nanometer of micrometer features. Claim 1 reads:

1. A gemstone comprising a plurality of facets, wherein one or more of the facets have a hazy white-colored appearance, said appearance associated with non-periodic nanometer and/or micrometer sized features on said facets.


Monday, December 05, 2011

Memistors, Memristors, and Memresistors

I recently posted an updated historical review of memory resistors available at this link which may be of interest in relation to ReRAM non-volatile memory and neuromorphic technology.


 In 2008 researchers at Hewlett-Packard announced the physical realization of the “memristor” which was theoretically predicted as a fundamental non-linear circuit element by Leon Chua in 1971. Since that time there have been numerous scientific papers applying the concept of memory resistors to a wide range of thin film materials used for a new type of non-volatile memory called ReRAM (resistive random-access memory). It has also been noted that memory resistors may be applicable to explain behavior of biological neurons and some research groups have developed circuit designs exploiting memory resistors as components of neuromorphic electronics. This article reviews the historical background of various forms of memory resistors including the Widrow-Hoff memistor, Chua’s memristor model, and a mem-resistor model I developed to correct some of the deficiencies in HP’s memristor model. The potential future of memory resistors with respect to artificial intelligence and robotics is briefly discussed.

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Thursday, December 01, 2011

US Patent 8068624 - CNT thermoacoustic sound generator

This is one of the latest patents from Hon Hai Precision (Foxconn) including basic claims for a new application of carbon nanotubes involving thermoacoustic transduction. Claim 20 reads:

20. An apparatus, the apparatus comprising:

a sound wave generator, the sound wave generator comprises a carbon nanotube structure;

the sound wave generator produces sound waves by a thermoacoustic effect.


US Patent 8067803 - Nanoparticle recombination sites built into DRAM memory transistor

Conventional DRAM memory cells include both a capacitor and a transistor but there has been an effort to produce DRAM cells without capacitors to decrease the cell size. This patent from Micron teaches a variation of this approach using nanoparticles as recombination sites for capacitor-less charge storage. Claim 1 reads:

1. A memory device comprising:

a partially depleted storage transistor at a surface of a substrate comprising:

a body portion located between a first source/drain region and a second source/drain region, the body portion including a heavily doped region of a second conductivity type having one of nano-particles and nano-inclusions located therein adjacent to the second source/drain region and separated from the first source/drain region, the first source/drain region and the second source/drain region comprising:

regions of a first conductivity type, and a gate structure, the gate structure wrapping at least partially around a body portion in at least two spatial planes;

a bit line connected to the first source/drain region; and

a word line connected to the gate structure.