Monday, December 31, 2007

Top Ten U.S. Nanotechnology Patents for 2007

Several hundred nanotech patents have issued over the past year. This is my list of the top ten based on the potential for near-term commercialization/value and claim breadth in light of the potential market.

10) US Patent 7,195,754 (Eikos Inc.)

This patent presents basic claims to carbon nanotubes as a component of sunscreen with advantages to UV blocking.

Claim 1 - "A sunscreen composition containing carbon nanotubes."

9) US Patent 7,179,561 (Nanosys)

This patent is basic to the use of nanowires in PEM fuel cells.

Claim 1 - "A fuel cell comprising inorganic nanowires which are derivatized with at least a first functional group which binds to a metal catalyst deposited on a surface of the nanowires, wherein the nanowires are deposited or directly grown on a proton exchange membrane of the fuel cell."

8) US Patent 7,274,998 (Intel)

This patent is basic to a near-field approach to high resolution maskless lithography.

Claim 1 - " An apparatus comprising: an array of nanowires placed at a distance to a resist layer, the array forming a plurality of light emitting diodes (LEDs), the distance corresponding to a near field region of light emitted by the LEDs with respect to the resist layer; and a control circuit coupled to the array to control the LEDs to emit the light to pattern a feature in the resist layer. "

7) US Patent 7,291,284 (Nanoink)

This patent is basic to the use of dip pen nanolithography in sub-50 nm lithography processes.

Claim 1 - "A method of nanolithography comprising: providing a substrate and a nanoscopic or SPM tip; using the tip to apply a patterning compound from said tip to the substrate so as to produce a desired pattern which is a chemical etching resist; and chemically etching the substrate. "

6) US Patent 7,272,010 (Advanced Micro Devices)

This patent is basic to the use of carbon nanotubes to enhance the thermal conductivity of a circuit board.

Claim 1 - "A circuit board, comprising: a substrate including a source material interspersed and in physical contact with a first plurality of unbundled carbon nanotubes; and at least one conductor coupled to the substrate."

5) US Patent 7,295,503 (Hewlett-Packard)

This patent is basic to the use of nanotubes as electron emitters for storing data in phase change or other material for high density memory.

Claim 1 - "A data storage device comprising an array of nanotubes as electron field emission sources."

4) US Patent 7,256,466 (Harvard)

This is the basic patent to functionalized semiconductor nanowires (important to sensors).

Claim 1 - "An article comprising: a semiconductor nanowire comprising a core region and an outer region surrounding the core region, wherein the outer region is selectively functionalized with a chemical or biological species added to the nanowire after construction of the nanowire. "

3) US Patent 7,312,155 (Intel)

This patent is basic to forming transistors from single nanowires.

Claim 1 - "A method comprising: etching a gap along the length of a nano-electrode to form a transistor."

2) US Patent 7,264,990 (Nantero)

This is a basic patent to semiconductor processing of nanotube films using a mask which is important for integrating carbon nanotube with current semiconductor fabrication methods.

Claim 7 - "A method of making a conductive article on a substrate, comprising: providing a substantially planar fabric of pre-formed nanotubes on the substrate; depositing a mask layer over the fabric of pre-formed nanotubes; defining a pattern in the mask layer, the pattern corresponding to the shape of the conductive article; removing nanotubes in accordance with the pattern of the mask layer to define the conductive article. "

1) US Patent 7,298,016 (Nantero)

This is a basic patent to carbon nanotube electronics using lithographically defined structures.

1. A circuit comprising: a structure having a conductive trace; and lithographically patterned element of pre-defined shape formed from a nanotube layer disposed in spaced separation from the conductive trace.


Friday, December 28, 2007

US Patent 7312915 - Low inertia MEMS

Texas Instruments is one of the first innovators in micromirror technologies. This latest patent teaches using low inertia materials to form the movable member which can enhance the responsiveness of the device to driving signals and reduce problems related to stiction. Claim 1 reads:

1. A microelectromechanical device, comprising: a microelectromechanical deflectable element held on a substrate such that the microelectromechanical element is capable of moving relative to the substrate, and wherein the element has a mass inertia of 1.2×10−24 kg·m2 or less.


US Patent 7312155 - Transistor manufucture by etching nanowire electrodes

There are quite a few proposed designs for using nanowires and nanotubes to form transistors. Companies such as Infineon and Samsung have focused on vertical transitor designs using nanowires or nanotubes, Hewlett Packard is forming crossbar architectures with doped nanowires, and Nanosys is using arrays of aligned nanowires to form FETs. This patent from Intel includes some broad claims to an approach that avoids alignment problems when different nanowires are used for the source and drain of a transistor by using a single nanowire which is etched to form a gap for the control electrode. Claim 1 reads:

1. A method comprising: etching a gap along the length of a nano-electrode to form a transistor.


Thursday, December 27, 2007

US Patent 7312096 - Nanotube wheatstone bridge sensor

This patent from Kulite Semiconductor Products teaches a method of forming a pressure sensor using nanotubes in a Wheatstone bridge configuration. Claim 1 reads:

1. A method of forming a pressure transducer comprising: providing a substrate; disposing a plurality of nanotube structures on a surface of said substrate, said plurality of nanotube structures having varying resistance values such that each of said plurality of nanotube structures corresponds to one of a conductive nanotube structure having a relatively low resistivity, and a semiconductive nanotube structure having a relatively high resistivity, and wherein at least one electrical property of said semiconductive nanotube structures changes with an applied force; selectively connecting at least some of said relatively high resistivity semiconductive nanotube structures to one another using at least some of said relatively low resistivity conductive nanotube structures to form a bridge circuit having a plurality of force sensitive bridge elements; wherein application of a force to said substrate causes a change in current through said bridge circuit according to the applied force.


US Patent 7311889 - Laminated trench for CNT growth

One of the difficulty in carbon nanotube production is that there are many flavors of nanotubes based on the chirality, orientation, and diameter and it is difficult to mass produce nanotubes of a specific type without producing other types that need to be sorted from the desired type. This patent from Fujitsu teaches an interesting solution based on a CVD process that uses a lamination of catalytic layers with a V-groove etched therein as the template for nanotube growth with well controlled diameter and directionality. Claim 18 reads:

18. A carbon nanotube production process comprising a step of preparing a substrate which is inclined in one direction from a specific symmetrical crystal orientation and vapor depositing a metal catalyst along the atomic steps appearing on the surface of the substrate, and a step of growing the carbon nanotubes by chemical vapor deposition (CVD) using the metal catalyst as nuclei.


Wednesday, December 26, 2007

US Patent 7311776 - Nanostructure synthesis using resistive nanostructure

High temperatures are often necessary in many of the techniques used to manufacture nanostructures. This patent teaches a room temperature approach resulting from the use of localized thermal effects from a resistive microstructure. Claim 10 reads:

10. A method of integrating a nanostructure with a wafer comprising at least one microelectronic device, comprising: establishing a resistive microstructure on the wafer; said resistive microstructure being thermally insulated from the microelectronic device; supplying current to the resistive microstructure to generate localized heat at a location on the microstructure while maintaining the microelectronic device at room temperature; and synthesizing one or more nanostructures at the location on the microstructure as a result of the localized heat at the location.


US Patent 7311774 - Branched nanocrystals

Polymeric nanoparticles such as dendrimers have the benefit of a very large surface-to-volume ratio due to a multibranched structure which allows for larger reactivity and greater functialization for applications in sensors or bioprobes. However, such multibranched structures are more difficult to duplicate in crystalline nanostructures. This patent from the University of California teaches a method of manufacturing multibranched nanocrystalline structures which can provide enhanced reactivity for applications such as fuel cells, photovoltaics, or sensors. Claims 1, 4, and 36 read:

1. A nanocrystal particle made by a process comprising: (a) providing a core having a first crystal structure in a solution; and (b) forming an arm extending from the core having a second crystal structure in the solution.

4. A nanocrystal particle comprising: a core having a first crystal structure; and at least an arm extending from the core having a second crystal structure.

36. A nanocrystal particle in the form a teardrop or an arrow.


Friday, December 21, 2007

US Patent 7310004 - Nanoscale crossbar PLA with restoring inverting arrangement

Both Nantero and Hewlett Packard have experimented with nanoscale crossbar arrays for logic devices in which different blocks or tiles of crossbars are configured to perform different logic functions. However one problem is signal loss and lack of inverting functions between the crossbar tiles. This patent from Andre DeHon teaches an interconnection of nanoscale crossbars that includes signal restoration and inversion so as to achieve programmable logic arrays. Claims 1, 71, and 72 read:

1. An array of programmable logic array (PLA) clusters each cluster comprising: a first plurality of nanoscale wires forming a first wired logic; a first restoring inverting arrangement connected with the first wired logic, the first restoring inverting arrangement comprising a second plurality of nanoscale wires crossing the first plurality of nanoscale wires, the first restoring inverting arrangement restoring and inverting signals of the first wired logic; and a third plurality of nanoscale wires crossing the second plurality of nanoscale wires and forming a second wired logic, wherein an output of at least one PLA cluster forms an input of at least one other PLA cluster.

71. An array of programmable logic array (PLA) nanoscale clusters wherein an output of at least one PLA cluster forms an input of at least one other PLA cluster.

72. An array of interconnected programmable logic array (PLA) nanoscale clusters comprising nanoscale wires adapted to perform logical functions of the individual PLA nanoscale clusters and adapted to propagate signals throughout the array.


Thursday, December 20, 2007

US Patent 7309902 - Anti-stiction bump for MEMS

Stiction is a significant problem for micromechanical devices which can hinder operation rendering a microsensor or microactuator inoperable. Two common solutions are the use of an anti-stiction coating and the use of spacer elements to prevent contact between the movable member and a susbstrate. This patent from HP teaches a hybrid solution which uses an anti-stiction coating patterned exclusively on a spacer bump which allows for stiction prevention without interference with electrical contact portions that could occur if the anti-stiction coating was coated indiscriminately. Claim 1 reads:

1. A microelectronic device, comprising: a movable plate including a lower surface; a bump positioned on said lower surface; and an anti-stiction coating positioned only on said bump.


US Patent 7309866 - MEMS cosmic ray detector

Cosmic rays can cause problems in electronics especially as the feature sizes continue to decrease. This patent from Intel teaches a cosmic ray microsensor to provide a warning for cosmic rays in proximity to circuitry. Claim 1 reads:

1. A chip comprising: an active region including first circuitry; a substrate supporting the active region; and a first cosmic ray detector, wherein the first cosmic ray detector is a micro-electro-mechanical systems (MEMS) cosmic ray detector.


Wednesday, December 19, 2007

US Patent 7309650 - Nanocrystal charge storage layer

This patent teaches a method of preventing oxidation of nanocrystals in a nanocrystal memory device by using a porous dielectric layer in which the material forming the nanoparticles is diffused. Claim 1 reads:

1. A method for manufacturing a memory device, comprising: providing a substrate; forming a first layer of dielectric material on the substrate; forming a porous dielectric layer on the first layer of dielectric material; diffusing an electrically conductive material into the porous dielectric layer to form a nanocrystal charge storage region; and forming a second layer of dielectric material on the porous dielectric layer.

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US Patent 7309517 - Silica/Zirconia nanoparticles for durable optical film

In order to improve the scratch resistance of brightness enhancing films this patent from 3M teaches the use of silica or zirconia nanoparticles in the film. Claim 1 reads:

1. A durable optical film comprising: a polymerized optical film structure having a microstructured surface and a plurality of substantially fully condensed surface modified colloidal nanoparticles of silica, zirconia, or mixtures thereof.


Tuesday, December 18, 2007

US Patent 7309404 - Arc discharge CNT manufacture using charcoal electrodes

The three main methods of carbon nanotube manufacture are laser ablation, CVD, and arc discharge. The arc discharge method forms carbon nanotubes via the application of a direct current discharge between graphite electrodes in a reduced pressure, inert gas atmosphere. This patent from Fuji Xerox teaches using charcoal in place of the graphite for cheaper cost production. Claim 1 reads:

1. A manufacturing method for a carbon nanotube, comprising: applying a voltage between two electrodes whose tips are opposed to each other; generating discharge plasma in a discharge area between the two electrodes; and using an electrode made of a porous carbonaceous material, wherein said porous carbonaceous material is charcoal as at least one of the two electrodes whose tips are opposed to each other.


US Patent 7309385 - 3D nanostructure gas separation membrane

Gas separation membranes must balance both the selectivity in the gases that are passed and the permeability of the membrane and an improvement in one of selectivity or permeability comes at the cost of the other. This invention provides a high surface area membrane structure using nanostuctured tubes to enhance the permeability without sacrificing selectivity. Claim 1 reads:

1. A gas separation membrane of two or more layers comprising a separating layer of 3-dimensional nanostructure and a supporting layer, wherein the 3-dimensional nanostructure contains the array of hollow tubes whose heads are closed and bottoms are open.


Friday, December 14, 2007

US Patent 7307571 - Nanowire crossbar binary signal converter

One problem with using nanowires in constructing logic devices is difficulty in distinguishing between high and low signal levels. This patent from HP teaches using an alternating signal to help distinguish the nanowire output. Claim 1 reads:

1. A binary signal converter that facilitates distinguishing an original direct signal on a nanowire by superimposing an alternating signal on the original direct signal, the binary signal converter comprising: an alternating signal source connected to the nanowire that superimposes an alternating signal with an initial amplitude on the nanowire; and a selective alternating signal filter that selectively passes the alternating signal from the nanowire to a signal sink.


US Patent 7307540 - Logic function in response to MEMS sensor

This patent from General Electric presents some broad claims to the combination of both sensing and logic functions in a MEMS device. Claim 9 reads:

9. A microelectromechanical system sensor, comprising: a sensing portion to generate a mechanical movement in response to a current to be sensed; and a logic portion to mechanically perform a logic function in response to the movement.


US Patent 7307448 - Interconnectable nanoscale computational stages

Hewlett-Packard has been developing nanowire crossbar architectures over the past several years for applications in high density and memory devices. This patent focuses on the interconnection of nanoscale logic and memory devices to construct computational devices. Claim 1 reads:

1. A nanoscale computational stage comprising: a nanoscale logic array formed by interconnections between a number of internal signal lines, a number of logic-array input lines, and a number of logic-array output lines; and a number of nanoscale latch arrays interconnected with the nanoscale logic array, wherein each nanoscale latch array includes at least one enable line, a first control line, and a second control line that are selectively interconnected with the logic-array output lines and/or the logic-array input lines.


Thursday, December 13, 2007

US Patent 7307272 - 3D electronics using armchair and zigzag nanotubes

Two of the necessary materials for most electronic devices are metals and semiconductors. This patent from Kia Silverbrook (priority going back to 1999) presents some very broad claims to single walled carbon nanotube electronics formed from a 3D network of metallic (armchair) and semiconductor (zigzag) nanotubes. Claim 1 reads:

1. A network of electronic devices, said network comprising an organized matrix of armchair nanotubes and zigzag nanotubes.


US Patent 7307271 - Columnar nanowire interconnect

The increase in density of electronics devices have increased the demand for multilayer system electronics. This patent from Hewlett-Packard teaches using vertical nanowire connectors to provide electrical interconnects between such multilayer systems. Claim 14 is representative.

14. An interconnected nano-colonnade structure comprising: a first nano-colonnade device; a second nano-colonnade device; and a first nanowire column that extends nearly vertically from a (111) horizontal surface of the first device to a (111) horizontal surface of the second device that faces the (111) horizontal surface to connect the first device to the second device.


US 7307030 - Quantum dots formed in substrate concavities

Quantum dot films have been developed with various application in optoelectronics but one problem in forming such films is that the quantum dots are oriented in a random manner making it very difficult to form electronics devices that implement quantum cellular logic or quantum computing. This patent from Fujitsu teaches a method of using oxide to form recesses for quantum dot growth to produce controlled positioning of the quantum dots. Claim 1 reads:

1. A method for forming a quantum dot comprising the steps of: forming an oxide in a dot-shape on a surface of a semiconductor substrate; removing the oxide to form a concavity in a position where the oxide has been removed; and growing a semiconductor layer on the semiconductor substrate with the concavity formed in to form a quantum dot of the semiconductor layer in the concavity.


Wednesday, December 12, 2007

US Patent 7306845 - Novel optical nanoparticles

This patent from NeoPhotonics Corporation teaches a variety of new nanoparticle configurations useful for optical coatings. Some representative claims are listed below.

1. A collection of particles comprising a composition selected from the group consisting of LiNbO3 and LiTaO3, the collection of particles having an average diameter no more than about 500 nm.

4. A collection of particles comprising a metal/metalloid composition selected from the group consisting of a metal/metalloid arsinide, a metal/metalloid calcinate, a metal/metalloid telluride, a metal/metalloid phosphide and a metal/metalloid selenide, the collection of particles having an average diameter from about 3 nm to about 500 nm.

13. A collection of particles comprising a glass forming host composition, a first dopant/additive that introduces an absorption at a first wavelength of the electromagnetic spectrum and an emission at a second wavelength larger than the first wavelength and a second dopant/additive that creates a lasting change in index-of-refraction of the particles as a result of exposure to a third wavelength of electromagnetic radiation, the particles having an average primary particle diameter of no more than about 500 nm.

18. A collection of particles comprising a glass forming host composition, a first dopant/additive that introduces an absorption at a first wavelength of the electromagnetic spectrum and an emission at a second wavelength larger than the first wavelength, and a second dopant/additive that introduces paramagnetism to the particles.

22. A collection of particles comprising an oxide composition, the oxide composition comprising silicon, an alkali metal or alkali earth metal and a third metal/metalloid element, the collection of particles having an average particle diameter less than about 500 nm.


US Patent 7306828 - Ceramic nanocomposite thermal barrier

Ceramic have been used in thermal barriers but due to their brittle properties have limited applicability. This patent from Rice University uses fullerene or carbon nanotube materials to enhance the mechanical characteristics of ceramic thermal barriers. Claim 1 reads:

1. A method of protecting a surface of an object with a thermal barrier, the method comprising: providing a mixture comprising (a) a ceramic host material and (b) a nanostructured carbon material selected from the group consisting of single-wall carbon nanotubes, multi-wall carbon nanotubes, vapor grown carbon fibers, fullerene molecules, carbon fibrils, buckyonions, nested fullerenes, endohedral fullerenes, metallofullerenes, and combinations thereof; heating the mixture so as to form a ceramic nanocomposite having a nanoporous structure; and coating the surface of the object with said ceramic nanocomposite.


US Patent 7306823 - Coated copper/gallium nanoparticles for solar cells

Nanosolar is a developer of lower cost solar cell fabrication using printing technologies. This patent teaches using coated copper or gallium nanoparticle as a precursor material for copper indium/gallium diselenide (CIGS) solar cells as an alternative to oxide based particles which required reduction steps to be included in the fabrication. Claim 20 is representative.

20. A method for fabricating coated nanoparticles, comprising the steps of: obtaining core nanoparticles containing one or more elements from group IB and/or IIIA and/or VIA and coating the core nanoparticles with one or more layers of metal from group IB, IIIA or an element from group VIA in a controlled fashion such that the resulting coated nanoparticles have a desired stoichiometric ratio of elements, wherein the core nanoparticles include copper and gallium.


Tuesday, December 11, 2007

US Patent 7306822 - Ceramic nanopowder for forming passive electronic devices

This patent from Nanoproducts Corp. teaches forming passive electronics components such as capacitors, resistors, or inductors from ceramic nanoparticle films. Claim 1 reads:

1. A method for manufacturing a product comprising one or more passive electronic components, wherein the method comprises: providing ceramic nanopowders; suspending the nanopowders in a solvent thereby preparing a nanopowder dispersion or paste; forming a layer from the nanopowder dispersion or paste such that the average grain size of the nanopowder in the layer is equal to or less than 100 nanometers; and wherein the layer provides at least one passive electronic device function selected from the group consisting of capacitor, resistor, varistor and inductor; and processing the layer into one or more passive electronic components.


US Patent 7306778 - Smooth nanocrystalline diamond film

Diamond nanocrystalline films have advantages of hardness, wear resistance, electrical insulation, and thermal conductivity but the inclusion of polymer or graphite materials degrade these benefits. This patent from Nanotech Capital teaches fabrication methods that eliminate these defects to produce a purer and smoother diamond film coating. Claim 1 reads:

1. A film comprising a nano-crystalline diamond matrix, wherein the nano-crystalline diamond matrix is substantially free of graphite inclusions and wherein the film has an average root mean square surface roughness of less than 5.00 nm.


US Patent 7306316 - Nanoscale inkjet printing using cryogenic fluid

Nanolithography processes have adapted various printing techniques including inkjet printing to provide selective deposition of nanomaterials. This patent teaches an inkjet printer adapted to use superfluidic helium to facilitate the breakup of the ejected droplets into nanoscale components. Claim 1 reads:

1. A jet apparatus for nanoscale printing onto a substrate comprising a print head and a translational apparatus housed in a housing comprising at least one housing chamber; a reservoir comprising a cryogenic fluid in communication with the print head; and a dopant injector mechanically coupled to a storage containment comprising dopant molecules; and wherein at least one droplet of the cryogenic fluid is discharged from the print head and is expelled across at least a part of the housing chamber to combine with at least one dopant molecule discharged from the dopant injector, and wherein the combined at least one droplet of the cryogenic fluid and the at least one dopant molecule collides with the substrate positioned on the translational apparatus.


Monday, December 10, 2007

US Patent 7305571 - Intelligent power distribution using MEMS crosspoint switch array

For large integrated circuits different operating modes may require different distribution of power to be supplied. This patent from IBM proposes micromechanical switching arrays to perform redistribution of supplied power in ICs to supply variable distribution based on a dynamic system configuration. Claim 1 reads:

1. A power distribution network of an IC chip comprising: a first group of parallel power lines, and a second group of parallel power lines, wherein said first group of power lines transverse orthogonal to said second group of power lines; an array of MEM (microelectricalmechanical) switches between said two groups of power lines having one MEM switch located at each cross-point of said two transverse power lines; a MEM switch control signal is provided for each MEM switch to control “on/off” of the respective MEM switch; a look-up table of the current demand for the various sub-systems on the chip for a selected series of system modes and operating conditions; and a comparison engine to compare the system state and its associated current demand to that for the system configuration and active processes being used at the time.


Friday, December 07, 2007

US Patent 7304357 - Clamped nanotube films for non-volatile memory

In order to avoid problems created by stiction forces on the microscale several MEMS technologies have adapted spacer structures to limit the motion of the movable member. This patent from Nantero seems to deal with the same problem confronting nanotube ribbons used in non-volatile memory. Claim 1 reads:

1. A nanotube article, comprising: a first structure; a conductive trace of defined orientation disposed on the first structure, wherein the trace has a central region and a plurality of edges, wherein the trace comprises a plurality of unaligned nanotubes, each nanotube generally extending along the trace, wherein each nanotube is not constrained to being parallel to the orientation of the trace; and a first clamp in contact with the trace and with the first structure, wherein the first clamp overlaps a first defined region of the trace.


US Patent 7304103 - Carbon nanotube functionalization using diazonium

Diazonium salts are organic molecular structures which have been useful in functionalizing single-walled carbon nanotubes. This patent from James Tour's group at Rice University (with priority going back to 2001) seems to be a basic patent covering such functionalization. Claim 1 reads:

1. A method for making a polymer material comprising: (a) derivatizing carbon nanotubes with functional moieties to form derivatized carbon nanotubes, wherein the functional moieties are derivatized to the carbon nanotubes utilizing a diazonium specie; (b) dispersing the derivatized carbon nanotubes in a polymer.


Thursday, December 06, 2007

US Patent 7303875 - Nanowire chemfet

This patent is the latest by Nanosys focusing on applying nanowires for chemical sensing. Claim 1 reads:

1. A method of detecting a component of interest, the method comprising: (a) providing one or more nanowires, which nanowires comprise one or more functional groups comprising a hairpin oligonucleotide, which functional group undergoes a change in charge in the presence of the component of interest, wherein the hairpin comprises a first end, a second end, and a central portion, wherein the first end and the second end are complementary to each other and the central portion is complementary to the component of interest, and wherein the first end comprises a charge moiety that is proximal to the nanowires; (b) contacting the one or more nanowires with a solution comprising the component of interest; wherein binding the component of interest to the central portion of the hairpin oligonucleotide unfolds the hairpin, thereby moving the charge moiety away from the nanowires, producing the change in charge which change in charge results in a detectable signal; and, (c) detecting the signal, thereby detecting the component of interest.


US Patent 7303815 - Thermal bimorph nanotape

Thermal bimorph cantilevers play an important part in enabling many micromechanical sensors and switches by using two metallic materials with differing thermal expansion coefficients so that the cantilever bends upon thermal actuation. This patent from the University of California teaches an oxidized nanoribbon which can form the same function but at a smaller scale. Claim 1 reads:

1. A nanotape, comprising: a nanoribbon substrate; and an oxide epitaxially deposited on a flat surface of the nanoribbon substrate to form a two-layer nanotape having a generally rectangular cross-section.


Wednesday, December 05, 2007

US Patent 7303631 - ZnO nanowire array formed from patterned seed layer

One method of forming nanostructures is vapor-liquid-solid (VLS)growth which involve the use of catalytic particles such as gold. However, these particles are not easy to pattern and difficult to work with in ultraclean environment. This patent from Sharp offers an alternative for selectively patterned growth of zinc oxide nanostructures using atomic layer deposition of polycrystalline zinc oxide. Claim 1 reads:

1. A method of forming a zinc-oxide nanostructure, comprising: providing a substrate; forming a seed layer of polycrystalline zinc oxide on a surface of the substrate; patterning the seed layer; inducing growth of at least one zinc-oxide nanostructure substantially over the patterned seed layer.


US Patent 7303628 - Epitaxial growth of branched nanocrystal hetrostructure

The interface of two different semiconductor materials forms a heterostructure which can be useful in a variety of applications such as lasers and high frequency electronics. This patent from the University of California teaches the formation of a branched hetrostructure nanocrystal. Claim 1 reads:

1. A process of forming a nanocrystal heterostructure, the process comprising: (a) providing a nanocrystal comprising a first semiconductor material and comprising a first end, and (b) forming a segment comprising a second semiconductor material extending epitaxially from the first end to form a nanocrystal heterostructure.


Tuesday, December 04, 2007

US Patent 7303001 - Heat pipe with carbon nanotube operating fluid

This patent from Hon Hai Precision teaches the use of metal containing carbon nanocasules in the wick of a heat pipe for cooling semiconductor chips. Claim 1 reads:

1. A heat pipe comprising: a pipe; a wick engaged with an inside wall of the pipe; and an operating fluid sealed in the pipe and soaking the wick; wherein the operating fluid comprises a liquid and a plurality of carbon nanocapsules suspended in the liquid, and each of the carbon nanocapsules has a metal with high thermal conductivity received therein.


US Patent 7302832 - Scanning probe tips used to scan nanocode

Probe tips of atomic force microscopes or scanning tunneling microscopes are often used to characterize biological samples. This patent from Intel teaches using "nanocodes" which may take the form of carbon nanotubes combined with a reactive molecule to form an identification pattern for analytes to be detected by a scanning probe tip array. Claim 1 reads:

1. A surface analysis device, comprising: a substrate having a pattern on a surface of the substrate to orient a plurality of nanocodes, each nanocode comprising a tag element and a reactive molecule; a scanning array comprising a plurality of microscopy tips configured to simultaneously scan a plurality of tag elements of the plurality of the nanocodes on the surface of the substrate; and an analyzer coupled with the scanning array configured to receive simultaneously scanned information from the scanning array and utilizing the simultaneously scanned information to identify at least a portion of a sample molecule associated with the nanocodes and removed from the substrate prior to the simultaneous scan of the plurality of the tag elements, wherein the sample molecule is different from the plurality of the nanocodes.