Thursday, March 29, 2007

US Patent 7196450 - Nanoscale peristaltic pump

Peristaltic pumps are used to transport fluid using a series of rollers that mechanically displace fluid through a path. This patent from Ambient Systems takes the concept of peristaltic pumping to the nanoscale level by providing an array of electrically movable nanowires each of which emulate the motion of a jumprope to mechanically guide molecules along a path. Claim 1 reads:

1. An assembly immersed in a working substance having a plurality of molecules comprising: a base member; a first nanometer-scale beam fixed to said base member, wherein a portion of said first beam is free-to-move and said first beam has a first electric charge; and a charge member placed in the proximity of said first beam, wherein said charge member has a second electric charge, said first and second electric charges interact to provide motion of said free-moving portion, and said motion changes the average velocity of at least a few of said plurality of molecules along a desired direction; a second nanometer-scale beam fixed to said base member, wherein said second beam has a second portion that is free-to-move; and a channel having an input opening and an output opening, wherein said first and second beams are located in said channel between said input and output openings, wherein said desired direction is along a line from said input opening to said output opening.

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Wednesday, March 28, 2007

US Patent 7196386 - Spin polarized memory using fullerene

Memory devices that use electron spin rather than electron charge to store data have been experimented with using mostly paramagnetic and semiconductor materials. This patent from Sony explains that the use of fullerene films in forming spin conduction layers allows for a longer coherence length for the spin to allow for practical operation. Claim 1 reads:

1. A memory element wherein recording information is written by injecting spin-polarized electrons, the memory element comprising: a spin conduction layer made of a spherical shell or cylindrical molecule material having a hollow portion, and wherein the spin-polarized electrons are conducted by the spin conduction layer.

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US Patent 7195938 - Nanotube coating for field emitter fabrication

Nano-proprietary is a very active player in the application of electron emitting carbon nanotubes. They have the licence of the basic patent for this technology and are commercializing a new type of flat panel display using surface electron emission displays (SEDs). This patent claims a fabrication method which provides SED fabrication using low tech. solutions. Carbon nanotubes are printed on a substrate using inkjet technology and scotch tape is used to remove access nanotubes leaving a sufficient density to form the SEDs.

1. A method for making a field emission cathode comprising the steps of: depositing a carbon nanotube ("CNT") mixture on a cathode structure using a spraying process; contacting the deposited CNT mixture with an adhesive material; and separating the adhesive material from the deposited CNT mixture.

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Tuesday, March 27, 2007

US Patent 7195780 - Nanotube with particle cap

This patent teaches a nanotube (silica or polymer rather than carbon) with a nanoparticle "cap" for delivering bio-active agents. Claim 1 reads:

1. A nanotube comprising: (a) a hollow tubular body defining an inner void, comprising a first end and a second end, wherein the first end is open; and (b) a first end cap positioned over the first open end, wherein the end cap is attached to the hollow tubular body by a covalent bond and the capped nanotube has a maximum dimension of less than 100 microns.

US Patent 7195754 - Nanotube sunscreen

This may be a new record for broad nanotechnology patent claims. Claim 1 reads:

1. A sunscreen composition containing carbon nanotubes.


Thursday, March 22, 2007

US Patent 7193261 - Quantum supercapacitor

Supercapacitors are electrical storage devices with high energy density storage and recharging capabilities made by materials having a large specific surface. However, traditional materials used for supercapacitors are difficult to integrate with electronic memory because heavy ions are used in the electrical storage. This patent proposes the use of nanostructured clusters in a specific spatial arrangement to facilitate such integration. Claim 1 reads:

1. A quantum supercapacitor comprising at least two electrodes, the interval between which is filled by nanostructured materials, including at least one cluster with a tunnel-transparent gap, wherein each cluster has a characteristic size determined in the range 7.2517 nm<=r<=29.0068 nm, the thickness of each tunnel-transparent gap being less than or equal to 7.2517 nm, the spacing between the electrodes being more than 7.2517 nm.

US Patent 7192873 - Nanoparticles as sacrificial material

In microfabrication it is common to use polymer or oxide thin films as sacrificial material to form spacers which are later removed to form 3-D microstructures. This patent from Samsung does the same thing on the nanoscale using nanoparticles instead of thin films as the sacrificial material to form nanoscale diodes, transistors, or other electronic devices. Claim 1 reads:

1. A method of manufacturing a nano scale semiconductor, the method comprising: dispersing uniformly a plurality of nano particles on a semiconductor substrate; forming an insulating layer covering the nano particles on the semiconductor substrate; partly removing upper surfaces of the nano particles and the insulating layer; selectively removing the nano particles from the insulating layer; and partly forming doped semiconductor layers in the semiconductor substrate by doping the semiconductor substrate through spaces formed by removing the nano particles.

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Wednesday, March 21, 2007

US Patent 7192642 - SWCNT film with high modulus and electrical conductivity

This patent from Georgia Tech proposes fabrication techniques to achieve single walled nanotube film of improved mechanical and electrical properties for electrode used in capacitors, fuel cells, or other electrical devices.

1. A film comprising at least about 80 wt % single-wall carbon nanotubes, wherein the film has a tensile modulus of at least about 6 GPa at 0.2% strain, wherein the film is on a substrate, and wherein the substrate is a fiber.


US Patent 7192533 - Multimaterial nanowire fabrication

Most often nanowire fabrication produces nanowires formed of the same type of material throughout the nanowire length but there is a desire for nanowires formed with multiple doping states or other divergent material properties to facilitate transistor, sensor or other device applications. This patent from Philips claims a basic method of constructing nanowires of pnp or npn material layer configurations. Claim 1 reads:

1. A method of manufacturing nanowires, comprising the steps of providing a patterned etching mask at a surface of a semiconductor substrate, and etching the semiconductor substrate so as to form nanowires In a direction substantially perpendicular to the surface of the semiconductor substrate, characterized in that the semiconductor substrate comprises a first layer of a first material, second layer of a second material, and a third layer of the first material, the second layer sandwiched between the first and third layers; and etching takes place through the first, second and third layers for forming the nanowires such that the nanowires comprise a first region of the first material, a second region of the second material and a third region of the first material.

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Monday, March 19, 2007

Free Nanomaterials Database

I recently put together a database of US patents issued over the last 25 years having at least one claim reciting a nanoparticle (or quantum dot), a nanowire (or quantum wire), or a nanotube. The database is sortable based on filing year and listed assignee (patent holder) and provides a valuation index (also sortable) for each patent in the database based on the number of claim limitations. If anyone is interested in a copy send an E-mail to

with "Nanomaterial database" in the subject and I'll send you a copy.

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US Patent 7190092 - Scrubbing MEMS contacts

Stiction is a problem commonly associated with micromechanical structures and results from chemical residue or electrostatic charges which can build up and leave a microstructure stuck in a particular position. This patent fro a company called Teravicta proposes a fairly basic solution involving controlled scrubbing of the MEMS surfaces to reduce the stiction effect. Claim 1 reads:

1. A micro-electromechanical switch module, comprising: a micro-electromechanical switch having a control element and a contact surface; and signal generation circuitry adapted to electrically, thermally or magnetically actuate the switch sufficient to provide repetitive scrubbing action between contacts of the switch during at least a portion of time when the switch is closed.


Friday, March 16, 2007

US Patent 7190049 - Vertical nanowire array in polymer matrix

Co-polymer self-assembly is frequently being used to create templates to form large arrays of nanostructures on a substrate. This patent from the University of Massachusetts uses co-polymer self assembly to produce ultrahigh density nanowire arrays with high magnetic coercivity for magnetic storage applications. Claim 1 reads:

1. A nanoscale array comprising an electrically-conductive substrate and nanowires arranged in parallel on the substrate, the nanowires each having a diameter of 1.0 to 100 nanometers, and having a periodicity of 1.0 to 100 nanometers; and a polymer matrix between the nanowires, wherein the substrate is a metal substrate.

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US Patent 7189681 - C20 superconductor

This is an interesting case for enablement issues (35 USC 112 1st) of nanotech cases which went to the Board of Patent Appeals for the US patent office. The patent claims a fullerene superconducting wire based on C20 but was rejected by the Examiner based on insufficient test data to justify the claim of superconductivity. The Examiner was reversed by the Board which stressed the burden on the Examiner to establish a prima facie case of non-enablement even when the patent application is lacking in test data. Claim 1 reads:

1. A superconducting material comprising a structure wherein C.sub.20 Fullerene molecules are polymerized into a one-dimensional chain.

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Thursday, March 15, 2007

US Patent 7189635 - Interlaced nanowire fabrication

The fabrication of nanowires on a substrate often employs non-conventional manufacturing processes such as self-assembly and nanoimprint lithography. This patent from HP proposes a mixture of processes, the first of which forms a first array of parallel nanowires and the second of which reduces the diameters of the first nanowires to form a second set of nanowires between the first nanowires so as to allow for higher wire densities to be formed. Claim 1 reads:

1. A method of reducing feature dimensions of a nano-scale device comprising: consuming a surface of a device substrate, the device having a pattern of spaced apart first nanowires on the surface, the consumption reducing a dimension of the first nanowires; and forming a second nanowire in a trench between adjacent ones of the first nanowires, such that the device comprises a set of features that includes the first nanowires with the reduced dimension and the second nanowire spaced from the adjacent first nanowires by sub-trenches.

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US Patent 7189476 - Rechargeable batteries using metal encapsulating nanotubes

Conventional rechargeable lithium cells have problems related to dendrite growth on the anodes during cycling. This patent proposes metal encapsulating carbon nanotubes as a material to achieve improved capacity and reversibility. Claim 1 reads:

1. A rechargeable lithium cell incorporating an anode, a reversible cathode, and an electrolyte, said anode comprising carbon nanotubes, characterized in that the nanotubes contain within them a metal or a metalloid selected from the group consisting of aluminum, tin, metallic alloys containing aluminum or tin, or silicon, that can form alloys reversibly with lithium over a range of compositions wherein the metal or metalloid is inside said nanotubes.

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US Patent 7189472 - Nanofibers for fuel cell

The large surface-to-volume ratio of nanostructured materials has made these materials favorable as catalytic carriers for fuel cells. This patent from Toshiba uses nanofibers with high aspect ratios with aluminum oxide powder to improve power efficiency of fuel cells. Claim 1 reads:

1. An electrode for a fuel cell comprising: a film including: carbon nano-fibers having particle diameters of 5-1000 nm and an aspect ratio of particle diameter to particle length of from 1:10 to 1:1000; aluminum oxide powder; fuel cell catalyst carried on a surface of said carbon nano-fibers; and ion conductive material.

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Tuesday, March 13, 2007

US Patent 7189455 - Carbon nanotube/nanocrystal heterostructure

In order to create useful electronic structures from nanotubes they need to be connected to other electrical elements. This patent from the State University of New York teaches how to manufacture a nanotube/nanocrystal mixture wherein the nanotubes are linked to the nanocrystals via oxygen mediated covalent bonding so as to create a nanostructure more easily integrated in electronic systems. Claim 1 reads:

1. A fused heterostructure comprising a carbon nanotube and at least one nanocrystal, wherein the nanocrystal is directly attached by a covalent linkage to at least one oxygen moiety on the nanotube, and wherein there is no intermediary linker between the nanotube and the nanocrystal.

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US Patent 7189430 - Simultaneous vertical and horizontal CNT growth

Fabrication of high density nanotube arrays on a substrate has been achieved by a variety of catalytic growth methods, but most of these methods are constrained to forming vertical arrays. This patent from Rensselaer Polytechnic Institute proposes a method capable of forming both horizontal and vertical nanotube arrays on a substrate simultaneously. Claim 1 reads:

1. A method of making carbon nanotubes, comprising: providing a substrate containing a plurality of oxide template structures having at least a portion covered by a masking material; providing a nanotube source gas onto the plurality of oxide template structures; and selectively growing the carbon nanotubes on an exposed portion of each of the oxide template structures but not on exposed portions of the substrate and not on portions of the oxide template structures covered by the masking material; wherein the step of selectively growing the carbon nanotubes comprises simultaneously growing carbon nanotubes of a different length by providing the nanotube source gas for a sufficient time to allow the carbon nanotubes growing on the exposed portion of each oxide template structure to contact the masking material covering the covered portion of an adjacent template structure.


US Patent 7187201 - Molecular programmable logic

Xilinx is the leading company in programmable logic devices which typically work by using an arrays of logic circuits (NAND, NOR, etc.) and fuses (or anti-fuses) which can be programmed to achieve a desired logical function. This patent proposes the use of switchable molecules such as rotaxane to achieve programmable logic. Claim 1 reads:

1. A circuit comprising: a programmable cross-wire interconnect, the programmable cross-wire interconnect including: a first plurality of wires; a second plurality of wires oriented with respect to the first plurality of wires so that a first one of the first plurality of wires crosses a first one of the second plurality of wires at a non-zero angle to form a programmable junction; wherein the programmable junction includes a first molecule coupled between the first one of the first plurality of wires and the first one of the second plurality of wires; and wherein the first molecule has a first energy state and a second energy state; a logic device including an input terminal and an output terminal, wherein at least one of the input terminal and the output terminal is coupled to the first one of the first plurality of wires; and at least one of a pullup device and a pulldown device coupled to the logic device, wherein the at least one of a pullup device and a pulldown device includes a second programmable junction formed between the first one of the first plurality of wires and a third wire, wherein the second programmable junction includes a second molecule coupled between the first one of the first plurality of wires and the third, and wherein the second molecule has a first energy state and a second energy state.

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Thursday, March 08, 2007

US Patent 7186398 - Fe/Au nanoparticle

This patent from Purdue Research proposes a new paramagnetic nanoparticle in which the magnetic moment can be precisely controlled and which can be readily modified by attachment of selected organic molecules to their surfaces. Claim 1 reads:

1. A superparamagnetic nanoparticle comprising Fe atoms and Au atoms distributed in a solid solution with no observable segregation into Fe-rich or Au-rich phases or regions.


US Patent 7186380 - Molecular transistor with switchable polarization

Hewlett-Packard has made a lot of headway in recent years in molecular electronics. Most of their patents in this field are concerned with nanoscale crossbar arrays but this patent focuses on a transistor employing polarizable molecular material. Claim 1 reads:

1. A transistor comprising: (a) a source region and a drain region separated by a channel region having a length L within a range of about 1 to 100 nm, formed on a substrate, wherein said channel region comprises a semiconductor material; (b) a dielectric layer on at least a portion of said channel region; (c) a molecular layer on said dielectric layer, said molecular layer comprising molecules having a switchable dipolar moiety; (d) a gate electrode having a thickness w within a range of about 1 to 100 nm on said molecular layer; and (e) said molecules having a polarization direction and magnitude, at least one of which is capable of being changed in response to an electric field applied between said gate electrode and said dielectric layer.

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Tuesday, March 06, 2007

US Patent 7186020 - Silicon grease/nanotube thermal interface

A goal of thermal interface materials is to be formed of small thicknesses and/or low resistivities. This patent from the University of Washington proposes a carbon nanotube/silicone grease/chloroform composition with a fraction of the thermal impedance of conventional thermal interface material. Claim 1 reads:

1. An apparatus, comprising: a thermal interface material (TIM) having: a matrix including silicone thermal grease, the matrix further including chloroform; and a filler disposed in the matrix, the filler comprising carbon nanotubes.


Monday, March 05, 2007

US Patent 7184717 - MEMS antenna switch

One of the key advantages of mechanical switches over electrical switches is that when a mechanical switch is off there is a physical disconnection which prevents current flow while transistors or other electrical switches have a degree of leakage current. While typical mechanical switches are large compared to transistors, MEMS switches can be fabricated at a sufficiently small scale to be competitive. This patent from Intel presents a broad claim for a MEMS switch for a wireless communication system. Claim 1 reads:

1. A portable communication device comprising: a first transceiver; a first microelectromechanical system (MEMS) switch to couple the first transceiver to an antennae, wherein the first MEMS switch has an input node directly connected to the antennae; and a field effect transistor switch coupled to an output of the first MEMS switch.

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Friday, March 02, 2007

US Patent 7183568 - Piezoelectric/Nanotube memory

The electrical conductivity of carbon nanotubes is believed to be highly sensitive to strain and stress. This patent form IBM attempts to take advantage of this property to form electronic devices using a piezoelectric layer for gate control. Claim 1 reads:

1. A memory device, comprising: at least one memory cell comprising: a layer of piezoelectric material; and a nanotube structure mounted such that a change of shape of said piezoelectric material causes a change in a stress in said nanotube structure.

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US Patent 7183122 - Scanning probe sub-surface circuit modification

Scanning tunneling microscopes and atomic force microscopes were fundamental innovations developed in the 1980's to detect on the nanoscale. More recently these devices (collectively referred to as scanning probe microscopes) have been applied to nanofabrication processes such as etching and coating as well as detection. This patent from Intel has basic claims to subsurface circuit processing using these tools. Claim 1 reads:

1. A method comprising: machining a hole on an integrated circuit with a scanning probe system; and performing a circuit edit through the hole formed by said system.

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