Patent application number | Description | Published |
20080295762 | METHOD FOR CONTROL OF SHAPE AND SIZE OF PB-CHALCOGENIDE NANOPARTICLES - Disclosed is a method for producing, controlling the shape and size oft Pb-chalcogenide nanoparticles. The method includes preparing a Pb (Pb) precursor containing Pb and a carboxylic acid dissolved in a hydrocarbon solution and preparing a chalcogen element precursor containing a chalcogen element dissolved in a hydrocarbon solution. The amount of Pb and chalcogen in the respective precursor affords for a predetermined Pb:chalcogen element ratio to be present when the Pb precursor is mixed with the chalcogen element precursor. The Pb precursor is mixed with the chalcogen element precursor to form a Pb-chalcogen mixture in such a manner that Pb-chalcogenide nanoparticle nucleation does not occur. A nucleation and growth solution containing a surfactant is also prepared by heating the solution to a nucleation temperature sufficient to nucleate nanoparticles when the Pb-chalcogen element mixture is added. Upon injection of the Pb-chalcogen element mixture into the heated nucleation and growth solution, Pb-chalcogenide nanoparticles nucleate and a Pb-chalcogenide nanoparticle solution is formed, which is thereafter cooled to a growth temperature that is below the nucleation temperature. The Pb-chalcogenide nanoparticle solution at the growth temperature is held at the growth temperature for a predetermined time period such that a desired nanoparticle size is obtained. The Pb:chalcogen element ratio and a surfactant in the nucleation and growth solution can control the shape of the Pb-chalcogenide nanoparticles. The nucleation temperature, the growth temperature, the time at which the Pb-chalcogenide nanoparticle solution is held at the growth temperature and a surfactant can control the size of the Pb-chalcogenide nanoparticles. | 12-04-2008 |
20080315175 | ALIGNMENT, TRANSPORTATION AND INTEGRATION OF NANOWIRES USING OPTICAL TRAPPING - Individually trapping, transferring, and assembling high-aspect-ratio semiconductor nanowires into arbitrary structures in a fluid environment. Nanowires with diameters as small as 20 nm and aspect ratios of above 100 can be trapped and transported in three dimensions, enabling the construction of nanowire architectures which may function as active photonic devices. Moreover, nanowire structures can now be assembled in physiological environments. In one aspect, nanowires are positioned to direct light to remote samples, reducing exposure of the overall sample to intense source illumination. A tunable nanowire probe for subwavelength imaging is also described utilizing efficient second harmonic generation (SHG) whose optical frequency conversion allows implementing subwavelength microscopes. | 12-25-2008 |
20090169807 | LANGMUIR-BLODGETT NANOSTRUCTURE MONOLAYERS - Methods for assembly of monolayers of nanoparticles using the Langmuir-Blodgett technique, as well as monolayers, assemblies, and devices are described. The surface properties of these monolayers are highly reproducible and well-defined as compared to other systems. These monolayers can readily be used for molecular detection in either an air-borne or a solution environment, and sensors using the monolayer could have significant implications in chemical and biological warfare detection, national and global security, as well as in medical detection applications. | 07-02-2009 |
20090225310 | SURFACE-ENHANCED RAMAN SPECTROSCOPY SUBSTRATE FOR ARSENIC SENSING IN GROUNDWATER - A surface-enhanced Raman spectroscopy (SERS) substrate formed from a plurality of monolayers of polyhedral silver nanocrystals, wherein at least one of the monolayers has polyvinypyrrolidone (PVP) on its surface, and thereby configured for sensing arsenic is described. Highly active SERS substrates are formed by assembling high density monolayers of differently shaped silver nanocrystals onto a solid support. SERS detection is performed directly on this substrate by placing a droplet of the analyte solution onto the nanocrystal monolayer. Adsorbed polymer, polyvinypyrrolidone (PVP), on the surface of the nanoparticles facilitates the binding of both arsenate and arsenite near the silver surface, allowing for highly accurate and sensitive detection capabilities. | 09-10-2009 |
20090263912 | NANOWIRES AND NANORIBBONS AS SUBWAVELENGTH OPTICAL WAVEGUIDES AND THEIR USE AS COMPONENTS IN PHOTONIC CIRCUITS AND DEVICES - A microfluidic optical sensor utilizes at least one subwavelength nanowire or nanoribbon waveguide coupled to a fluidic structure having at least one nanofluidic channel through which one or more molecular species are conveyed. In response to optical pumping (e.g., a laser source) the waveguide optically interrogates nearby molecular species retained within said fluidic structure to detect chemical species in response to optical characterization of small (on the order of sub-picoliter) volumes of solution. Characterization is performed in response to evanescent wave sensing. In one aspect, optical characterization is selected from the group of optical characterizations consisting of absorbance, fluorescence and surface enhanced Raman spectroscopy (SERS). | 10-22-2009 |
20090293928 | Process For Altering Thermoelectric Properties Of A Material - A process for altering the thermoelectric properties of an electrically conductive material is provided. The process includes providing an electrically conducting material and a substrate. The electrically conducting material is brought into contact with the substrate. A thermal gradient can be applied to the electrically conducting material and a voltage applied to the substrate. In this manner, the electrical conductivity, the thermoelectric power and/or the thermal conductivity of the electrically conductive material can be altered and the figure of merit increased. | 12-03-2009 |
20090294908 | Diluted magnetic semiconductor nanowires exhibiting magnetoresistance - A method for is disclosed for fabricating diluted magnetic semiconductor (DMS) nanowires by providing a catalyst-coated substrate and subjecting at least a portion of the substrate to a semiconductor, and dopant via chloride-based vapor transport to synthesize the nanowires. Using this novel chloride-based chemical vapor transport process, single crystalline diluted magnetic semiconductor nanowires Ga | 12-03-2009 |
20110114145 | NANOSTRUCTURES HAVING HIGH PERFORMANCE THERMOELECTRIC PROPERTIES - The invention provides for a nanostructure, or an array of such nanostructures, each comprising a rough surface, and a doped or undoped semiconductor. The nanostructure is an one-dimensional (1-D) nanostructure, such a nanowire, or a two-dimensional (2-D) nanostructure. The nanostructure can be placed between two electrodes and used for thermoelectric power generation or thermoelectric cooling. | 05-19-2011 |
20110168968 | FLUIDIC NANOTUBES AND DEVICES - Fluidic nanotube devices are described in which a hydrophilic, non-carbon nanotube, has its ends fluidly coupled to reservoirs. Source and drain contacts are connected to opposing ends of the nanotube, or within each reservoir near the opening of the nanotube. The passage of molecular species can be sensed by measuring current flow (source-drain, ionic, or combination). The tube interior can be functionalized by joining binding molecules so that different molecular species can be sensed by detecting current changes. The nanotube may be a semiconductor, wherein a tubular transistor is formed. A gate electrode can be attached between source and drain to control current flow and ionic flow. By way of example an electrophoretic array embodiment is described, integrating MEMs switches. A variety of applications are described, such as: nanopores, nanocapillary devices, nanoelectrophoretic, DNA sequence detectors, immunosensors, thermoelectric devices, photonic devices, nanoscale fluidic bioseparators, imaging devices, and so forth. | 07-14-2011 |
20110233512 | VERTICAL INTEGRATED SILICON NANOWIRE FIELD EFFECT TRANSISTORS AND METHODS OF FABRICATION - Vertical integrated field effect transistor circuits and methods are described which are fabricated from Silicon, Germanium, or a combination Silicon and Germanium based on nanowires grown in place on the substrate. By way of example, vertical integrated transistors are formed from one or more nanowires which have been insulated, had a gate deposited thereon, and to which a drain is coupled to the exposed tips of one or more of the nanowires. The nanowires are preferably grown over a surface or according to a desired pattern in response to dispersing metal nanoclusters over the desired portions of the substrate. In one preferred implementation, SiCl | 09-29-2011 |
20120171778 | FUNCTIONALIZATION OF NANOFLUIDIC CHANNELS - A functionalized nanofluidic channel and method for functionalization that provides control over the ionic environment and geometry of the nanofluidic channel with the immobilization of biomolecules on the inner surface of the channel and use of high ionic concentration solutions. In one embodiment, the surface charge of the nanochannel is controlled with the immobilization of a protein such as streptavidin in the nanochannel. In another embodiment, the biomolecules are receptors and changes in nanochannel conductance indicates ligand binding events. The functionalized nanofluidic channel can be easily adapted for use with microchannel arrays. | 07-05-2012 |