Wednesday, January 31, 2007

US Patent 7170120 - Nanotube transistor using delta doped region

Intel has a growing number of patents dealing with nanotube based transistor configurations. This patent focuses on improving the ON/OFF current ratio for nanotube FETs. Claim 1 reads:

1. A transistor comprising a Carbon nanotube channel between a doped semiconductor region and an undoped semiconductor region, said undoped semiconductor region between said Carbon nanotube and a delta doped region that is doped opposite that of said doped semiconductor region.

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US Patent 7170055 - Nanotube tip for magnetic force microscopy

Magnetic force microscopy is an offshoot of atomic force microscopy designed to detect magnetic properties on the sub-micron scale and is useful for characterizing high density magnetic memory recording media. This patent allows for characterizations of high aspect ratio pits in the magnetic media by attaching metal via a nanotube to the microscope tip. Claim 1 reads:

1. A nanotube-based tip arrangement comprising: a tip base; at least one nanotube having a fixed end coupled to the tip base and having a free end extending away from the tip base; a sticking layer of material coated onto the free end of the at least one nanotube; and a layer of metal material coated onto the sticking layer.

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Tuesday, January 30, 2007

US Patent 7169989 - Etching Using Nanopipette

Typically etching is a batch process in which a reactive gas or liquid dissolves away material from a substrate in order to complete a microfabrication step. However, this patent proposes a more precise, albeit slower, etching method that employs a nano-sized nozzle to deliver the etching chemical.

1. A process for introducing a three-dimensional configuration of micron to sub-micron size in a polymeric substrate comprising applying an enzyme for the selective removal of sub-unit parts of the polymer to at least one predetermined area of said polymeric substrate via a pipette with a nano-sized orifice.


US Patent 7169251 - Nanofluidic Channel Fabrication

Typically forming a structure in the nanoscale that is well known to be formed in the microscale is arguably obvious. However, the attorney prosecuting this patent from the Univ. of Michigan successfully argued the non-obviousness of this method of manufacturing a nanofluidic flow passage when the microfluidic version was known. Claim 1 reads:

1. A method of forming enclosed nanofluidic channels, said method comprising: providing a first substrate having a layer of a first material thereon; providing a second substrate; forming a slot of nanoscale depth along said second substrate, said slot being formed by nanolithography and etching; and bonding said first substrate to said second substrate such that said layer of said first material on said first substrate is adjacent said slot on said second substrate to define an enclosed nanofluidic channel therethrough.

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Sunday, January 28, 2007

US Patent 7167847 - DNA Computer

DNA is a candidate material for molecular computation devices. This patent from Fujitsu uses a genetic algorithm approach to "evolve" a solution to a complex computational problem by breaking the problem down into smaller parts. Claim 1 reads:

1. A DNA computer for carrying out computations using DNAs, comprising: a dividing part configured to divide a problem that is to be solved into a plurality of partial problems; and an operation part configured to obtain a DNA sequence corresponding to a solution to the problem, by combining DNA sequences corresponding to solutions of the plurality of partial problems.

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Wednesday, January 24, 2007

US Patent 7166786 - Nanoimprint Lithography Doping

Semiconductor fabrication used in making integrated circuits usually requires a step of adding a dopant material to silicon via diffusion or ion implantation which can be costly. Imprint lithography is an alternative maskless lithography technique being explored which basically uses a stamping method to directly transfer a pattern to a target substrate. This patent from Borealis Technical Ltd. has priority going back to 1998 and presents a fairly broad claim to using this technique for semiconductor doping. Claim 1 reads:

1. A method for the induction of a band gap in a substance, comprising the steps of: (a) mounting a material on a substrate, (b) forming at least one nanostructure in said material by pressing a nanostructured mold into said material, said nanostructure having a relief causing de Broglie interference of elementary particles.

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US Patent 7166663 - Nanoparticle/Microparticle Composition

Hardness and scratch resistance of materials may be improved by adding particulate matter. However, for optically transparent materials such particle additives may cause undesired haze and lack of clarity. This patent from Nanophase proposes an optimized mixture of nanoparticles and microparticles to balance the physical and optical benefits of particulate enhanced materials. Claim 1 reads:

1. A composition comprising: a matrix material; a first particulate fraction comprising an average particle size of from about 1 nanometer to 100 nanometers; and a second particulate fraction comprising an average particle size from about 0.25 microns to about 50 microns, wherein the first particulate fraction is present in an amount between about 35 to about 65 weight percent of the total added particulate fraction.

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Tuesday, January 23, 2007

US Patent 7165553 - Nanoparticles for Cigarettes

There is some concern about possible health issues arising from the use of nanoparticles in a variety of products. However, this patent from Philip Morris proposes the benefits of catalytic nanoparticles to reduce the level of carbon monoxide produced from cigarettes. So smokers may soon be able to stop worrying about the ill effects of carbon monoxide (but perhaps may start worrying about the ill effects of nanoparticle inhalation.) Claim 1 reads:

1. A smoking article composition comprising tobacco cut filler, cigarette paper and/or cigarette filter material further comprising a catalyst capable of converting carbon monoxide to carbon dioxide, wherein the catalyst comprises nanoscale catalyst particles dispersed within a porous aluminosilicate matrix, and wherein the nanoscale catalyst particles comprise iron oxide, and/or iron oxide hydroxide, and/or wherein the matrix further comprises magnesia, titania, yttria, ceria or mixtures thereof.

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Sunday, January 21, 2007

US Patent 7164744 - Nanotube Logic Drivers

Nantero is the leading U.S. patent holder for nanotube based electronics and, while most of their patents are directed toward non-volatile mechanical memory, more recent patents focus on nanotube based logic or other circuit configurations. This patent is directed toward nanotube switching circuits for driver circuitry .

1. An off-chip driver circuit, comprising: a differential input having a first and second signal links, each coupled to a respective one of two differential, on-chip signals; at least one output link connectable to an off-chip impedance load; and at least one switching element having an input node, an output node, a nanotube channel element, and a control structure disposed in relation to the nanotube channel element to controllably form and unform an electrically conductive channel between said input node and said output node; wherein the input node coupled to a reference signal and the control structure is coupled to the first and second signal links and the output node is coupled to the output link, and wherein the nanotube channel element is sized to carry sufficient current to drive said off-chip impedance load.

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US Patent 7164646 - Scanning Probe Memory Cell With >2 Storage States

Conventional memory states are digitally stored in magnetic or optical media in terms of binary values (i.e. 0 or 1.) Scanning probe/Atomic force microscopy have added phase change material to the types of media on which digital data can be written, allowing for bit sizes on the nanoscale and greater memory densities. However, these scanning probe memory devices still typically use binary storage. This patent from Hewlett Packard teaches using the scanning probe tip to form multilevel (>2) data storage to further increase memory densities. Claim 1 reads:

1. A storage device comprising: a storage medium having plural storage cells; and a probe to scan across a surface of the storage medium to program the storage cells, wherein the probe is adapted to selectively program each storage cell to one of more than two storage states, the probe to selectively program each storage cell to have a dent having one of plural depths that represent at least two of the storage states, and wherein the probe is operable to contact a surface of the storage medium to read a storage state of at least one storage cell during a read operation.

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Thursday, January 18, 2007

US Patent 7164209 - Optimized Nanowire Spacing for Electrical Contacts

In order to assure connection between electrical contacts using metallic or semiconducting nanowires this patent from Nanosys proposes using nanowires at least twice as long as the separation between the electrical contacts. Claim 1 reads:

1. A nanowire based device comprising first and second electrical contacts disposed on a surface of a substrate and at least first and second nanowires positioned in contact with both of the first and second electrical contacts, wherein the first and second electrical contacts are separated from each other by a distance that is less than 50% of an average length of the first and second nanowires.

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Wednesday, January 17, 2007

US Patent 7163794 - Nucleic Acid Nanorobot

Although I have seen some suggestions of nucleic acid based nanorobots in non-patent literature (and more suggestions in science fiction) there are few patents on such technology. This patent from New York University relies on the use of set and unset nucleic acid molecules acting to move molecular "feet" along nucleic acid "footholds." Claim 1 reads:

1. A nano-robotic system comprising a molecular multiped, a molecular path along which the multiped can travel in more than one direction, a plurality of different sequence specific nucleic acid set molecules, and a plurality of different sequence specific nucleic acid unset molecules, said multiped comprising two or more feet, each of which has a sequence specific nucleic acid end and each of which is joined to at least one other foot on said multiped by a tether, said molecular path comprising a plurality of sequence specific nucleic acid footholds disposed along the path and to which individual nucleic acid foothold each foot of said multiped docks in the presence of a sequence specific nucleic acid set molecule that attaches by cohesion to both a sequence specific nucleic acid end of a foot of said multiped and a sequence specific nucleic acid foothold of said molecular path, said sequence specific nucleic acid set molecule comprising (1) a portion which is capable of attaching by cohesion to a sequence specific nucleic acid end of a foot of said multiped, (2) a portion which is capable of attaching by cohesion to a sequence specific nucleic acid foothold of said molecular path, and (3) a toehold portion which is incapable of separately attaching to either said sequence specific nucleic acid end of a foot of said multiped or said sequence specific nucleic acid foothold of said molecular path to which portion (1) or (2) of said sequence specific nucleic acid molecule can attach, wherein a foot that is docked to a foothold by a sequence specific nucleic acid set molecule is released from said foothold in the presence of a sequence specific nucleic acid unset molecule which strips away the sequence specific nucleic acid set molecule from said foot and said foothold, said sequence specific nucleic acid unset molecule being capable of attaching by cohesion to all of said portions (1), (2) and (3) of said sequence specific nucleic acid set molecule.

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Tuesday, January 16, 2007

US Patent 7163659 - Vertical Nanowire Array Sensor

Nanostructures are of high interest to the area of sensors since the high surface-to-volume ratio of nanostructres allows for high precision detection of extremely small quantities. This patent from Hewlett-Packard teaches forming an array of electrically connected nanowires on a substrate to use as a chemical or bio. sensor. Claim 1 reads:

1. A sensor device, comprising: a substrate; an array of free-standing nanowires, said array comprising individual free-standing nanowires, each of said individual free-standing nanowires having a first end and a second end, said first end being attached to the substrate and said second end being unattached to the substrate, said individual free-standing nanowires configured for electrical communication with other individual free-standing nanowires through the first end; and a signal measurement apparatus electrically coupled to the array of free-standing nanowires for receiving electrical information from the array of free-standing nanowires.

However, there is some prior art in the field of scanning probe microscopy that use arrays electrically connected nanotubes as tips that might have been missed such as

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Sunday, January 14, 2007

US Patent 7162137 - Nanoparticle Cladding Optical Fiber

Silica glass is the most common material used for fiber optics due to its superior optical properties. However, it has several defects including insufficient fracture resistance and sensitivity to moisture. This patent from ERS Company proposes the use of nanoparticles to provide a thixotropic property (i.e. fluidity under stress) to the outer cladding of fiber optic cable so as to help solve these problems. Claim 1 reads:

1. An optical fiber comprising: a core; and a thixotropic cladding layer including a plurality of hydrophilic nano-particles proximate the surface of the core, and a plurality of hydrophobic nano-particles around a layer of the hydrophilic nano-particles.

Thursday, January 11, 2007

US Patent 7161285 - Nanotube / Particle Impurity Film

Usually the use of nanotubes in electronic structures requires some degree of purification of the nanotubes so as to remove soot or other carbon particulates. This patent makes use of the impurities in a nanotube film to fill in gaps and increase mechanical film strength. Claim 1 reads:

1. A carbon nanotube (CNT) film, comprising: CNTs and particulate impurities, wherein said CNT film is formed as a stacked structure of a plurality of layers stacked in sequence, and the content ratio of said CNTs and said particulate impurities in each of said layers of said stacked structure is set independently of other layers.

Wednesday, January 10, 2007

US Patent 7161094 - MEMS Package with Environmental Control

Stiction is a detrimental effect in microdevices involving the sticking of a movable portion of the microdevice in an undesired position. Changes in the local humidity or partial pressure within a housing of a microdevice can result in an increase in such stiction effects. This patent teaches the provision of materials to counteract environmental changes in a MEMS package in order to prevent stiction or other detrimental effects. Claim 1 reads:

1. A display device, comprising: a package; at least one microelectromechanical system (MEMS) device enclosed within the package, the MEMS device comprising a movable element configured to contact another surface; and an environmental control material inside the package, wherein the amount of the environmental control material is selected to affect an operation of the MEMS device.

Tuesday, January 09, 2007

US Patent 7160532 - Nanotube Array on Metal Substrate

Carbon nanotube arrays are generally formed on non-metallic substrates since metallic substrates create difficulty in growing nanotubes that are pure and straight. However, in applications requiring a high current source to the nanotubes a metallic substrate would be useful as an electrode. This patent from Hon Hai Precision discloses a method of nanotube array fabrication on metal substrates. Claims 1 and 12 read:

1. A method for forming a carbon nanotube array, comprising the following steps: providing a metal substrate; oxidizing the substrate to form an oxidized layer on a surface of the substrate; depositing a catalyst layer on the oxidized layer; and introducing a carbon source gas; whereby the carbon nanotube array formed extends from the metal substrate.

12. A carbon nanotube array subassembly comprising: a metal substrate; and a carbon nanotube array formed thereon; wherein a material of the metal substrate is selected from the group consisting of tantalum, nickel, silver and steel, the metal substrate having an upper face, the upper face being oxidized to form an oxidized layer thereon.

US Patent 7160169 - Photolithography of Carbon Nanotube Emitters

Electron emission from carbon nanotube arrays are currently being applied in flat panel displays by a number of different companies such as Samsung and Canon. This patent from Samsung teaches how to use conventional optical lithography processes to the mass production capabilities of such nanotube arrays. Claim 1 reads:

1. A method of manufacturing carbon nanotube emitters, the method comprising: forming a carbon nanotube layer on a substrate on which a plurality of electrodes are formed; coating a photoresist on the carbon nanotube layer; patterning the photoresist such that the photoresist only remains above the electrodes; removing an exposed portion of the carbon nanotube layer by etching using the patterned photoresist as a etch mask; and removing the patterned photoresist and forming the carbon nanotube emitters on the electrodes.

Monday, January 08, 2007


I recently started another patent blog similar to TinyTechIP called MachineLearningIP. It will be similar to this blog but focus on recent patents related to issues in A.I. such as evolutionary computing and morphware (i.e. reconfigurable electronics).

Sunday, January 07, 2007

US Patent 7157990 - Nanotube RF Fiter

As nanotechnology gradually moves from a basic materials science toward more commercial applications a search for optimum configurations of nanomaterials in electrical, optical and mechanical devices is sought. Currently it is infeasible (or at least extremely difficult) to manufacture devices that use singular nanostructures for such devices, however arrays of oriented nanostructures are being developed in the form of nanotube ribbons (Nantero) or nanowire arrays (Nanosys). This patent from Northrop Grumman Corp. forms a radio frequency filter using an array of nanotubes. Claim 1 reads:

1. A radio frequency (RF) filter, comprising: a substrate; a dielectric layer formed on first and second portions of said substrate; a ground plane formed on a third portion of said substrate, said third portion being at least, in part, between said first and second portions; a carbon nanotube array being formed on a portion of said ground plane between said first and second dielectric layers; and first and second signal guides formed on the first and second dielectric layers, such that an RF signal may be input to and output from said carbon nanotube array via said first and second signal guides.

Thursday, January 04, 2007

US Patent 7156911 - Dental Nanoparticles

There is some interest in using nanoparticles for dental adhesive. This patent from 3M claims:

1. A hardenable dental composition comprising: (a) a polyacid; (b) an acid-reactive filler; (c) at least 15 weight percent of a nanofiller or combination thereof, each nanofiller having an average particle size of at most 200 nanometers; and (d) water.

which is similar to an earlier patent from Dentsply DeTrey GmbH

Wednesday, January 03, 2007

US Patent 7155959 - Nanodisk Sensor

Nanoink is a company which is commercializing technology based on dip pen nanolithography which basically uses a nanoscopic tip to directly write patterns on a substrate. This patent employs dip pen techniques to form gas sensors on the nanoscale which may possess greater sensitivity than conventional sensors. Claim 1 reads:

1. A sensor for temperature and gas detection comprising a sol gel nanodisk fabricated between conducting electrodes whereby the sol gel nanodisk comprises a semi-crystallized structure having surface oxygen ions.

Monday, January 01, 2007

Top Ten U.S. Nanotechnology Patents for 2006

Based on the U.S. nanotechnology I've seen in the past year and the current areas of commercialism I've put together a list of what seem to be the most economically valuable (or in certain cases controversial) U.S. patents.

U.S. Patent 7048903 (Rice University/Carbon Nanotechnologies)
Claim 1- "A dispersion of single-walled carbon nanotubes in a liquid comprising an aqueous detergent solution."

This is important for the separation of tangled nanotubes which is critical to the use of these materials in any one of the large variety of nanotube applications.

U.S. Patent 7052618 (Agilent Technologies)
Claim 1- "A nanostructure fabrication method, comprising: forming on a substrate a film including a vector polymer comprising a payload moiety; patterning the film; and removing organic components of the patterned film to form a payload-comprising nanoparticle."

Provides the common mass production processes of optical lithography for nanoparticle processing leading to potential for faster processing and greater fabrication precision for nanostructures.

U.S. Patent 7105596 (Rice University/Carbon Nanotechnologies)
Claim 1- "A composite material comprising: (a) a matrix, wherein said matrix comprises a polymer; and (b) a single-wall carbon nanotube material embedded within said matrix, wherein said single-wall carbon nanotube material comprises fibers of greater than 1,000,000 single-wall carbon nanotubes."

Basic patent for single walled nanotube/polymer composites applicable for stronger lightweight materials.

U.S. Patent 7132994 (Ambit Corp.)
Claim 1- "A resonant nanotube structure responsive to electromagnetic energy, said nanotube structure comprising: a substrate; and an ordered array of resonant nanotubes arranged on said substrate."

Basic patent for nanotubes used in light sensors and a variety of communication devices.

U.S. Patent 7153703 (University of Arkansas)
Claim 1- "A nanoparticle composition comprising: a nanoparticle coated with a plurality of dendron ligands covalently bound to a surface of the nanoparticle."

Avoids oxidation of nanoparticles and may be critical to use on nanoparticles in bioassays and other medical applications.

U.S. Patent 7120047 (Nantero)
Claim 1- "A selection system, comprising: a set of devices; a selector circuit to select at least one of the devices for access, the selector circuit comprising switches, each switch having a nanotube ribbon switching element."

Basic patent to nanotube ribbon electronics that is being commecialized by Nantero (reportedly this year).

U.S. Patent 7125605 (M.I.T.)
Claim 1- "A population of coated nanocrystals each comprising a size-selected core including a first semiconductor material and an overcoating including a second semiconductor material, wherein the population of coated nanocrystals exhibit photoluminescence having a quantum yield of greater than about 30%."

Provides for higher efficiency quantum dots useful in LED and biomarker applications.

U.S. Patent 7064372 (Nanosys)
Claim 1 - "An article, comprising a population of nanowires disposed in a thin film on a surface of a substrate, wherein: the population of nanowires is substantially oriented in a first direction; and the thin film has an area of greater than 10 square cm"

Basic patent for the nanowire macroelectronics that is being applied to RFID, solar cell, large area display, and other flexible electronic devices by Nanosys.

U.S. Patent 7099071 (Ambit Corp.)
1. A method of moving a carbon nanotube which is attached by one end thereof, to a junction on a substrate, said method comprising: applying a charge to said carbon nanotube; and providing a repelling force to an adjacent structure from said carbon nanotube to which said charge has been applied.

Basic patent to nanotubes used in nano-actuators, nano-motors, and a variety of nano-mechanical devices. Potentially overlapping with the nanotube mechanical memory devices planned to be commercialized by Nantero.

U.S. Patent 7148619 (Canon)
Claim 1 - "An electronic device comprising: (i) a first and a second electrodes; and (ii) a carbon nanotube electrically connecting the electrodes."

Basic patent for nanotube electronics.