Thursday, July 30, 2009

US Patent 7567414 - Nanotube electrostatic discharge protection circuit

One key advantage of carbon nanotubes to electronics is their ability to withstand current densities greater than 100 times that of copper. This patent from Nantero takes advantage of this property in forming an electrostatic discharge protection circuit. Claim 1 reads:

1. An electrostatic discharge (ESD) protection circuit for protecting a protected circuit coupled to an input pad from an ESD-induced voltage of positive or negative polarity, comprising:

a nanotube switch having at least two terminals coupled to the protected circuit and to a single discharge path;

wherein the nanotube switch, in response to the ESD-induced voltage, switches between a de-activated state and an activated state;

wherein the activated state creates a current path in either direction between the at least two terminals, so that a signal on the input pad flows to or from the single discharge path to cause the signal at the input pad to remain within a predefined operable range for the protected circuit, wherein the nanotube switch returns to the de-activated state after the duration of the ESD-induced voltage.


US Patent 7566657 - Nanoparticle based growth of interconnect vias

The development of 3D stacked semiconductor circuit architectures is of interest to continue Moore's Law. One issue in this area is the development of high aspect ratio vertical interconnects to connect the different layers. This patent from HP teaches using nanoparticle catalysts to induce the growth of such interconnects. Claim 1 reads:

1. A method of forming at least one through-substrate interconnect, comprising:

providing a semiconductor substrate having a first surface and an opposing second surface;

forming at least one opening in the semiconductor substrate, the at least one opening extending from the first surface to an intermediate depth within the semiconductor substrate, the at least one opening partially defined by a base;

providing at least one metal-catalyst nanoparticle on the base instead of the sidewalls;

growing conductive material within the at least one opening under conditions in which the metal-catalyst nanoparticle promotes deposition of the conductive material onto the base; and

removing material of the semiconductor substrate from the second surface to expose a portion of the conductive material filling the at least one opening.


Wednesday, July 29, 2009

US Patent 7566478 - Patterned carbon nanotube fabric

The two main ways of integrating carbon nanotubes with electronics is 1) to prefabricate the carbon nanotubes which are introduced into a paste of ink and deposited on a substrate used to form the electronic device or 2) to directly grow carbon nanotubes onto the substrate. This patent from Nantero focuses on the second method to pattern carbon nanotube fabric into an electrical interconnect. Claim 1 reads:

1. A method of making an article, comprising:

applying carbon nanotube growth catalyst on to a surface of a substrate;

subjecting the substrate to a chemical vapor deposition of a carbon-containing gas to grow a non-woven fabric of carbon nanotubes, wherein the nanotubes of the fabric are substantially parallel to said surface of the substrate;

selectively removing portions of the non-woven fabric according to a defined pattern; and

providing first and second electrodes in contact with respective first and second portions of the patterned non-woven fabric to create the article, wherein the patterned non-woven fabric forms a conductive trace between the first and second electrodes.


US Patent 7566476 - High spectral purity quantum dots

This patent is from M.I.T. and has some relatively early priority (1997) to a method of nanocrystal separation to produce a narrow spectrum photoluminescence from the nanocrystals. Claim 1 reads:

1. A method of producing a population of coated nanocrystals that exhibit photoluminescence having a quantum yield of greater than about 30%, comprising:

synthesizing a plurality of nanocrystal cores made from a first semiconductor material; and

size-separating a select population of nanocrystal cores from the plurality of synthesized cores, wherein the population of coated nanocrystals emit light in a spectral range of no greater than about 40 nm full width at half max (FWHM) when irradiated.


Monday, July 27, 2009

US Patent 7564269 - Integrated CNT/FET switch

This patent from Nantero teaches an integrated semiconductor and nanotube field effect switching structure with higher potential integration density and operating speed than conventional CMOS designs. Claim 1 reads:

1. A nonvolatile power control device comprising:

an input terminal;

an output terminal in electrical communication with a circuit to be controlled;

a control structure, electrical stimulation of the control structure controlling the formation of an electrically conductive channel between the signal input terminal and the output terminal, a first portion of the electrically conductive channel including a nanotube channel element and a second portion of the electrically conductive channel including a field modulatable semiconductor channel element;

wherein the formation of the electrically conductive channel controls power to the circuit to be controlled.


US Patent 7564262 - Mem-resistor Crossbar Comparator

Memory resistors are a new type of nanoscale circuit element which have been popularized in the last year due to interest by Hewlett Packard. One key advantage of mem-resistors is the ability to integrate data storage and signal processing functions in a single circuit element in order to achieve real time pattern recognition and control system functions. This patent teaches a crossbar circuit architecture using memristive junctions to perform an analog comparison function to achieve such real time responsiveness in applications such as audio/speech recognition and robotics. Further information is available at this link.
Claim 19 reads:

19. A device including:

a first plurality of crossbar columns storing first stored data in the form of high or low resistance states;

a second plurality of crossbar columns storing second stored data in the form of high or low resistance states; and

a summing amplifier electrically connected to an output row associated with one of the first or second plurality of crossbar columns, wherein the second stored data stored in the second plurality of crossbar columns have complementary values to the first stored data stored in the first plurality of crossbar columns.

Thursday, July 23, 2009

US Patent 7564246 - CNT field emission pressure sensor

Carbon nanotube (CNT) field emitters are most often mentioned for applications in displays but another potential application is in pressure gages. This patent teaches an improved version of a CNT pressure gage with less potential damage to the nanotube emitters by using a multiple grid system. Claim 1 reads:

1. A pressure sensor using a field emission of a carbon nano-tube, comprising:

an array of carbon nano-tubes formed on a metallic layer;

a first grid disposed on the array of the carbon nano-tubes;

a second grid disposed on the first grid such that the second grid is spaced apart by a first distance from the first grid; and

a collector disposed on the second grid such that the collector is spaced apart by a second distance from the second grid,

whereby electrons emitted from the carbon nano-tube are collided with gas molecules to be ionized forming an ionized cation, and the ionized cation is sensed by the collector to be outputted as an electrical signal.


US Patent 7564085 - Vertical nanowire mechanical memory

This patent from Samsung teaches a new type of nanostructured memory device which uses a mechanically movable nanowire to store charge on a capacitive nanowire. Claim 1 reads:

1. A memory device comprising:

an insulating substrate;

a source electrode formed on the insulating substrate;

a drain electrode formed on the insulating substrate and spaced apart from the source electrode;

a nanowire capacitor formed on the source electrode, the nanowire capacitor including a first nanowire grown vertically from the source electrode, a dielectric layer formed on the outer surface of the first nanowire, and a floating electrode formed on the outer surface of the dielectric layer;

a second nanowire grown vertically from the drain electrode, the second nanowire bending towards the nanowire capacitor while a voltage is applied to the drain electrode; and

a gate electrode formed on the insulating substrate and spaced apart from the drain electrode, the drain electrode being arranged between the source electrode and the gate electrode.


US Patent 7563722 - Nanotexturing of multicrystalline silicon

This patent from Applied Nanotech teaches a way to increase the efficiency of multicrystalline silicon solar cells by using nanoparticles to enhance the texture of the silicon surface. Claim 1 reads:

1. A method for texturing a surface of a multicrystalline silicon (mc-Si) substrate, comprising the steps of:

applying a layer of nano-sized particles onto the surface of the mc-Si substrate; and

bombarding the surface of the mc-Si substrate with plasma ions over a period of time so that the plasma ions that pass through openings in the layer of nano-sized particles etch the surface of the mc-Si substrate more substantially than the surface of the mc-Si substrate lying beneath the nano-sized particles resulting in a texturing of the surface of the mc-Si substrate to thereby increase light scattering properties of the mc-Si substrate, wherein the nano-sized particles comprise fullerenes.


Wednesday, July 22, 2009

US Patent 7563428 - High yield SWCNT fabrication

This patent from the University of Oklahoma has some early priority (June 2, 1999) and teaches a CVD manufacturing method with a relatively high yield of carbon nanotubes of the single walled variety. Claim 1 reads:

1. A method for selectively producing single-walled carbon nanotubes, comprising:

providing catalytic particles comprising at least one Group VIII metal, excluding iron, and at least one Group VIb metal selected from the group consisting of Mo and W;

providing a carbon containing gas; and

feeding the catalytic particles and the carbon-containing gas into a reactor wherein the catalytic particles and carbon-containing gas are mixed at a temperature sufficient to catalytically produce a solid carbon product comprising carbon nanotubes wherein single-walled carbon nanotubes comprise 80% or more of the solid carbon product and wherein amorphous carbon, graphite and multi-walled carbon nanotubes comprise 20% or less of the solid carbon product.


US Patent 7563411 - CNT array manufacturing with multiple gas flow inlets

This patent from Hon Hai Precision teaches a device to facilitate the measurement of growth rates of carbon nanotube arrays by using a secondary gas inlet to provide a disturbance gas to quickly stop growth. Claim 1 reads:

1. A device for manufacturing a carbon nanotube array, the device comprising:

a reaction chamber having a first gas inlet, a second gas inlet, and a gas outlet;

a supporting component located in the reaction chamber; and

a gas introducing tube connecting the second gas inlet with the supporting component.


US Patent 7562433 - Metal nanofiber fabrication

This patent from Oxford Semiconducting Technology teaches an unusual method of nanofiber fabrication based on repeated steps of deforming and stacking a metal matrix having metal rods inserted therein. After a few iterations of these deformation and stacking steps, gold wires of 0.1'' diameter are converted to nanofibers. Claim 1 reads:

1. A method of forming nanofibers of metals or metal alloys comprising the steps of:

inserting rods comprising fiber metal or alloy into holes drilled into a matrix metal billet, mechanically deforming this billet to a rod of smaller size, then restacking these smaller rods into a subsequent matrix metal billet; and

repeating the steps multiple times until the rods have been reduced to nanofibers of a desired diameter.


Friday, July 17, 2009

US Patent 7561760 - Optical beam steering using nanowires

This patent from Northrop Grumman teaches electrically or magnetically steering optical signals transmitted in nanowires. Claim 1 reads:

1. A method for steering optical frequency beams using nanowire, comprising:

providing one or more nanowire waveguide arrays;

generating an optical frequency beam, wherein the optical frequency beam is incident on the one or more nanowire waveguide arrays;

controlling the one or more nanowire waveguide arrays to produce a phase delay in the optical frequency beam as it travels through nanowire waveguide array, wherein the phase delay causes the optical frequency beam to deflect upon exiting the one or more nanowire waveguide arrays; and

steering the optical frequency beam exiting the one or more nanowire waveguide arrays by increasing or decreasing the phase delay, wherein the angle of deflection of the exiting optical frequency beam is determined by the gradient of the phase delay.


US Patent 7560707 - Plasmonic up-converter

Up-conversion materials provide a conversion from infrared to visible light offering an alternative to cathode ray tubes and LCDs for a lighter display structure. This patent from Hewlett-Packard teaches using surface plasmons formed in a nanostructured surface to increase the efficiency of such materials. Claim 1 reads:

1. A plasmonic up-converter apparatus, comprising:

an excitation source operable to emit electromagnetic radiation at an excitation frequency; and

at least one array of nanofeatures configured to produce an emission spectrum responsive to irradiation with the electromagnetic radiation, the emission spectrum having a number of distinct emission peaks, wherein a first emission peak is associated with a fundamental harmonic frequency, a second emission peak is associated with a second harmonic frequency, and a third emission peak is associated with a third harmonic frequency, the fundamental harmonic frequency approximately equal to the excitation frequency and the second and third harmonic frequencies greater than the fundamental harmonic frequency.


US Patent 7560394 - Silicon nanodot on insulator structure

Silicon nanodots or nanocrystals are useful for constructing high efficiency LEDs, lasers, photodetectors, or floating gate memory. However, it is difficult to achieve uniform size and spacing of semiconductor nanodots. This patent from Samsung teaches using an underlying layer of metal nanodots formed in a self-assembled pattern to facilitate the formation of silicon nanodots in a top layer. Claim 1 reads:

1. A nanodot material, comprising:

a silicon substrate;

a plurality of metal dots on the silicon substrate;

a silicon oxide layer on the silicon substrate and having a plurality of stress concentrating regions in locations corresponding to the metal dots; and

a plurality of silicon nanodots on the silicon oxide layer and in locations corresponding to the stress concentrating regions.


Wednesday, July 15, 2009

US Patent 7560366 - Process for horizontal nanowire growth

There have been numerous techniques developed for the direct growth of silicon nanowires on a substrate. However, most of these techniques result in vertically grown arrays of nanowires while horizontal nanowires have required pre-fabrication of the nanowires and deposition onto the substrate which can be more complex than a direct growth process and require special alignment steps. This patent from Nanosys teaches a horizontal growth method which may be easier to implement and useful to the fabrication of nanowire transistors and sensors. Claim 1 reads:

1. A process for producing silicon nanowires, comprising:

(a) providing a base substrate;

(b) forming one or more nucleating particle comprising gold (Au) on the base substrate;

(c) forming a nanowire growth-inhibiting layer on the one or more nucleating particle; and

(d) contacting the nucleating particle with one or more precursor gas mixtures suitable for the growth of silicon nanowires, whereby silicon nanowires are grown from a side surface of the nucleating particle.

One similar prior art patent is US 6,515,339.


US Patent 7560134 - Bead blasting nanoparticle implantation

The patent from Applied Nanotech teaches a method of depositing nanoparticles into a surface using beads of glass or ice as carrier particles. This can provide a simpler alternative to other deposition methods using nanoparticles embedded in printing pastes which require additional post-processing steps and produce smaller surface densities of the nanoparticles.
Claim 1 reads:

1. A method for altering properties of a surface, comprising the steps of:

providing a target surface for alteration; and

performing an implantation of nanoparticles into the target surface, wherein:

said implantation is performed with a bead-blasting process using carrier beads, such that the carrier beads strike the target surface; and

mixing said nanoparticles with said carrier beads before performing said implantation, such that said nanoparticles become physically attached to said carrier beads.


US Patent 7559758 - Nanoimprinting stamp with flow ducts

Nanoimprint lithography offers a potential route to 10 nm lithography and better using a patterned stamp structure to shape a polymer or resin material. However, residual polymer and resin can require cleaning of the stamp surface and lack of uniformity in the patterned structures. This patent from the French National Center for Scientific Research teaches the formation of built-in ducts to remove access polymer and to facilitate uniformity of thickness in the material to be patterned. Claim 1 reads:

1. A mould for nano-printing, comprising recess and projection type patterns, said mould comprising:

one or several ducts, each providing a communication between a mould pattern and a reservoir area,

wherein a duct has a cross-section that is smaller than a surface area of a pattern at which the duct opens up.


Wednesday, July 08, 2009

US Patent 7557372 - Programmable conductivity nanoparticle films

The popularization of the memristor by Hewlett-Packard has opened the possibility of a variety of new circuit architectures providing reconfigurable electronics and new types of electronic memory. This patent from the University of California teaches a nanoparticle film with similar programmable characteristics. Claim 1 reads:

1. A composition for the formation of an electric field programmable film, the composition comprising:

a matrix precursor composition or a dielectric matrix material;

wherein the dielectric matrix material comprises an organic polymer and/or a inorganic oxide;

and an electron donor and an electron acceptor of a type and in an amount effective to provide electric field programming,

wherein the electron donor consists essentially of nanoparticles having sizes in a range of 1 nm to 100 nm.


US Patent 7556826 - Chewable nanoparticle composition for drug delivery

This patent from GP Medical teaches a nanoparticle drug delivery system for oral administration of proteins or peptides and suitable for animal feeding. Claim 1 reads:

1. A chewable composition for feeding an animal subject comprising a filler substance and nanoparticles that are blended with said filler substance, said nanoparticles comprising:

a shell portion that is dominated by positively charged chitosan,

a core portion that contains negatively charged substrate,

wherein said negatively charged substrate is at least partially neutralized with a portion of said positively charged chitosan in the core portion,

wherein said substrate is PGA, and

at least one bioactive agent loaded within said nanoparticles.


Tuesday, July 07, 2009

US Patent 7556789 - Low temperature CNT synthesis

This patent from Central Michigan University teaches a carbon nanotube manufacturing method capable of being performed below 100 degrees centigrade and, in some embodiments, at room temperature using iron encapsulated dendrimers. Claim 1 reads:

1. A low temperature method for synthesizing carbon nanotubes, comprising:

decomposing a carbon source in a fluid in the presence of a catalyst under conditions where the catalyst catalyzes formation of a carbon phase comprising nanotubes;

wherein the carbon source comprises a halogenated hydrocarbon and the catalyst comprises a metal-encapsulated macromolecule, wherein the metal is selected from the group consisting of Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Mo, and W.


US Patent 7556746 - Nanotube applicator liquid for electronics fabrication

This patent from Nantero teaches a purified nanotube solution suitable for spin-coating processes used in the manufacture of integrated circuits. Claim 1 reads:

1. A method of making an applicator liquid containing nanotubes of high purity while achieving a stable distribution of nanotubes in the liquid for use in an electronics fabrication process, comprising:

dispersing nanotubes into a solvent at a concentration of at least one milligram of nanotubes per liter solvent without addition of surfactants or polymers to form the applicator liquid;

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

wherein the applicator liquid has a level of metal impurities that is less than about 1×1018 atoms/cm3; and

wherein the nanotubes are distributed in the solvent without substantial precipitation or flocculation.


US Patent 7556571 - CNT sheet for golf club head

This patent from Adams Golf teaches a carbon nanotube padding for a golf club head which makes it easier for beginning golfers to provide a good striking force. Claim 1 reads:

1. A golf club head, comprising:

a club head body, the club head body includes a striking face, a soleplate, a toe, a heel and a hosel;

the club head body including a body shell composed of the striking face, soleplate, toe and heel, wherein at least a portion of the body shell is composed of a flexible material consisting essentially of carbon nanotubes woven into a sheet of a predetermined size, the sheet having a density of less than approximately 2.5 g/cm3 and tensile strength of at least approximately 465 MPa/(g/cm3); and

an internal cavity of the body shell is pressurized;

wherein the striking face is composed of the flexible material that consists essentially of the carbon nanotubes woven into a sheet of a predetermined size.


Wednesday, July 01, 2009

US Patent 7553898 - Flame retardant plastics with nanostructured filler

This patent for the Research Foundation of the State University of New York teaches a flame retardant polymer composite incorporating nanomaterials and resistant to degradation when exposed to UV radiation. Claim 1 reads:

1. A flame retardant composition comprising:

from about 30% to about 50% by weight of a polyolefin;

from about 10% to about 25% by weight a brominated polystyrene or from about 30% to about 40% by weight decabromodiphenyl ether;

from about 10% to about 30% by weight of an exfoliated nanoclay; and

from about 5% to about 15% by weight carbon nanotubules or metal oxide fillers in the nanometer particle range.


US Patent 7553681 - CNT stress sensor manufacture

This patent from Intel teaches forming a carbon nanotube based sensor for detecting stresses formed between integrated circuit dies and packaging. Claim 1 reads:

1. A method comprising:

depositing a first array of carbon nanotubes (CNTs) aligned in a first orientation at a first location on a substrate or a die in a wafer;

intercalating the first array with polymer;

covering the first polymer-intercalated array with a nitride layer;

depositing a second array of CNTs aligned in a second orientation at a second location on the substrate or the die; and

intercalating the second array with polymer.