- Manufacturing Find out what NIST is currently working on in Manufacturing.
Jack Pevenstein
Technology Partnership Office
301-975-5519
nisttech@nist.gov
100 Bureau Drive, M/S 2200
Gaithersburg, MD, 20899
The method of the invention identifies damage to an in-service conductor associated with the delivery (transmission and distribution) of electric power. Electro-magnetic acoustic energy is generated in an in-service conductor associated with the delivery of electric power. Corresponding return electro-magnetic acoustic energy is then measured. Features are then extracted from the return electro-magnetic acoustic energy to characterize damage to the in-service conductor. The features may be extracted through a variety of signal processing techniques, such as wavelet signal processing. The extracted features may be classified using a neural network, fuzzy logic, or a combination of both.
A method and apparatus for measurement of stress in a specimen utilizing a motorized electromagnetic acoustic transducer (EMAT). Stress causes a rotation of the pure-mode polarization directions of SH-waves and a change in the phase of waves polarized along these certain directions. The method utilizes a rotating small-aperture EMAT, connected to a processor, to measure phase and amplitude data as a function of angle. The EMAT is placed on a workpiece at the location where the stress is to be measured. The acoustic birefringence B is determined from the normalized difference of these phases. From these data, an algorithm calculates values of B and φ. The workpiece is then stressed or its stress state is changed. The values are measured again at the same location. Stress is determined from the change in B and φ.
An electromagnetic acoustic transducer for inducing and sensing vibrations in a cylindrical object and methods of using an electromagnetic acoustic transducer to determine resonant frequencies and physical properties of cylindrical objects. The electromagnetic acoustic transducers produce specific modes of vibration in cylindrical objects including axial shear vibrations, torsional vibrations, radial vibrations and plane strain vibrations. The methods of determining physical properties of a cylindrical objects include comparing sensed resonant frequencies of the cylindrical object to known relationships between resonant frequency and the physical properties of interest. The methods can be used to determine the temperature, dimensions, elastic constants, and damping coefficients of cylindrical objects, the magnitude of a load applied to a cylindrical object, or the texture or grain orientation of the material forming a cylindrical object.
A novel AC technique in cavity ringdown spectroscopy that permits IXIO-IO absorption sensitivity with microwatt level light power has been developed. Two cavity modes, one probing the empty cavity and the other probing intracavity absorption, are excited simultaneously, but their intensities are temporally out of phase, with one mode decaying and the other rising. Heterodyne detection between the two modes reveals the dynamic time constants associated with the empty cavity and the additional intracavity gas absorption. The method offers a quick comparison between the on-resonance and off-resonance information, a prerequisite to reaching the fundamental shot noise limit. This simple and yet important improvement of cavity ringdown spectroscopy should lead to enhanced performance in a wide range of applications.
A new low temperature method for nanostructured metal and ceramic thin film growth by chemical vapor deposition (CVD) involves the use of a low pressure co-flow diffusion flame reactor to react alkali metal vapor and metal halide vapor to deposit metal, alloy and ceramic films. The reaction chemistry is described by the following general equation: (mn)Na+nMXm .fwdarw.(M)n +(nm)NaX where Na is sodium, or another alkali metal (e.g., K, Rb, Cs), and MXm is a metal-halide (M is a metal or other element such as Si, B or C; X is a halogen atom, e.g., chlorine, fluorine or the like; and m and n are integers). This reaction chemistry is a viable technique for thin film growth. In one mode, using the precursors of sodium metal vapor, titanium tetrachloride (the limiting reagent), and either argon or nitrogen gases, titanium (Ti), titanium nitride (TiN), titanium dioxide (TiO2), and titanium silicide (TiSi, Ti5 Si3, TiSi2, Ti5 Si4) thin films have been successfully grown on copper and silicon substrates. Conditions can be adjusted to prevent or minimize gas-phase particle nucleation and growth. Substrate temperatures can also be varied to prevent excessive salt deposition.
A thin-film thermocouple is provided which can be used at temperature of up to 900° C. The thin-film thermocouple includes: a silicon substrate; an SiO2 diffusion barrier layer formed on the substrate; a titanium oxide adhesion layer formed on the diffusion barrier layer; a palladium thin film formed on the diffusion barrier layer; and a platinum thin film formed on the diffusion barrier layer and overlapping a portion of the palladium thin film to form a thermocouple junction.
A system is disclosed for performing x-ray photoelectron emission analysis which uses a collimated x-ray beam directed to an optically polished sample at a small grazing angle of incidence, a fixed sample/electron spectrometer geometry, and an x-ray detector for detecting x-rays reflected off of the sample. With the system, an enhancement of the x-ray field at layer interfaces in a multilayer sample can take place. The system permits depth profiling of an over layer on a substrate, such as a metal or metal oxide on a metal substrate. The enhancement permits absolute calibration of depth-dependence. The system reduces lineshape distortions due to inelastic electron scattering of exiting photoelectrons and eliminates energy distortions due to changes in the sample position relative to the focal point of the electron spectrometer.
Multilayer, thin film multijunction integrated micropotentiometers are formed in an integral multifilm membrane form over a through opening in a nonmagnetic, dielectric substrate. Through the use of conventional photolithographic and etching techniques, integrated structures are formed to include either single elongate heater elements, bifilar heater elements, or trifilar heater elements with multiple return paths. Multijunction thermopiles and resistors are formed with the heater. The individual layers of silicon oxide or silicon nitride, are formed with conventional chemical vapor deposition, sputtering and other known techniques.
A manufacturing method for convective accelerometers and tilt sensor devices using CMOS techniques. An integrated circuit chip is produced which includes a silicon substrate having an integrated circuit pattern thereon including a heater element located centrally of the substrate and at least first and second thermocouple elements located on the substrate on opposite sides of the heater element. Thereafter, portions of the substrate surrounding and beneath the heater and thermocouple elements are etched away to suspend the element on the substrate and thus to thermally isolate the elements from the substrate. The substrate is etched up to the cold thermocouple junction of the thermocouple elements so the cold junction remains on the substrate.
The present invention provides a method for machining hard materials using the machining fluids containing long chain alcohol in which the machining fluid is applied to a machining tool and then lubricates the machining of the workpiece by the machining tool and protects the machining tool during machining. The method is particularly useful when used with machining tools having a Mohs hardness of at least 9 and is most particularly useful when used with diamond machining tools.
A low noise accurate signal generator for a calibration system or a radar system includes a generator of a digital data stream having a predetermined frequency spectrum incorporated therein. A series connected array of Josephson junctions is coupled to and excited by the digital data stream to provide a stream of pulses with quantum mechanically accurate time integral. A low pass analog signal filter is coupled to the pulses of accurate time integral for extracting analog signals of the predetermined frequency spectrum. For radar applications, a low phase-noise local oscillator of a fixed RF frequency and the output of the filter are coupled to a signal mixer which outputs low phase-noise chirped RF signals for use in generating transmit pulses for the radar system whereby enhanced detection of targets in "clutter" can be obtained.
A detector of X-ray and the like in which very good resolution of energy can be obtained. The device is based on two basic components. The first is the x-ray absorber in which an x-ray interacts with a film and converts its energy into heat. Because the absorber is operated at cryogenic temperatures, approximately the range of 0.01 Kelvin to 1 Kelvin, its heat capacity is small and causes a measurable temperature rise. The second component of the invention is a base layer of normal metal which absorbs the heat generated by the x-ray. The third component of the invention is the method to detect the temperature rise. This thermometer is based on a normal metal-insulator-superconductor tunnel junction, where part of the base layer is the normal metal. When the tunnel junction is electrically biased at a voltage slightly below the gap voltage of the superconductor, the electrical current that flows through the junction is sensitively dependent on the temperature of the normal metal.
A pyroelectric detector with significantly reduced microphonic noise sensitivity that includes a pyroelectric detector element constructed from a z-cut LiNbO3 or LiTaO3 electret. Selective domain reversal is accomplished in the electret by applying an electric field. Electrodes are attached to either surface of the electret spanning the domain reversed region and a portion of the original domain region to create areas of equal and opposite sensitivity. The detector is mounted in an electrically grounded container or housing. The detector may also be constructed having multiple detector regions to accommodate resonant acoustic frequencies of the electret, to function as a position sensor, or both. In other words, the position sensor has multiple domain regions that also accommodate acoustic frequencies. The detector may also be constructed having domain reversed regions placed on the electret in a periodic pattern having a geometry and spacing that is related to the acoustic impulse response of the electret. Needle domains may also be interspersed in portions or throughout the electret to scatter acoustic waves and thereby reduce acoustic noise. Multiple detectors can be produced in a simple and inexpensive manner using shadow masking techniques.
For titanium and titanium alloys in tribological applications under bound lubrication conditions, there are employed epoxy coatings adhered to the surface of the titanium or titanium alloy by a titanium oxide primer layer. The anti-wear properties of the epoxy coating can be improved by incorporation of an anti-wear filler such as diamond powder. These coatings improve the friction coefficient and anti-wear properties of the titanium and titanium alloys.
Oxygen-containing compounds, particularly compounds wherein the oxygen is present in OH-groups, such as alcohols, sulfonic and carboxylic acids, or metal salts thereof, serve as lubricants for ceramic materials, particularly silicon nitride materials under high stress and high load conditions.
Methods for reducing wear on silicon carbide ceramic surfaces comprise contacting the surface with a lubricating oil composition including an organic sulfide. Preferred organic sulfides are of the formula R1 --S--(S)n --R2 wherein R1 and R2 are individually selected from the group consisting of alkyl, aryl, arylalkyl and alkaryl groups and hydrogen, but not both R1 and R2 are hydrogen, and n is 0, 1 or 2.
An antioxidant additive for an engine or propulsion system lubricant subjected to high temperatures which includes a high molecular weight substituted phenolic carboxylic acid tetraester of pentaerythritol. A lubricant blend which is capable of solubilizing the antioxidant additive and includes a polyolester, a phosphate ester and at least one of a polyalphaolefin and an alkylated naphthalene.
A chemical process for producing bulk quantities of an iron-silica gel composite in which particle size, form, and magnetic state of the iron can be selected. The process involves polymerizing an ethanolic solution of tetraethylorthosilicate, ferric nitrate and water at low temperature under the influence of an HF catalyst. The chemical and magnetic states of the iron in the resultant composite are modified in situ by exposure to suitable oxidizing or reducing agents at temperatures under 400° C. Iron-containing particles of less than 200 angstrom diameter, homogeneously dispersed in silica matrices may be prepared in paramagnetic, superparamagnetic, ferrimagnetic and ferromagnetic states.
Aluminum hydroxides are used as solid lubricants for aluminum oxides, ceramics and other materials having oxide surfaces. Aluminum oxide hydroxides and aluminum trihydroxides are preferred compositions for such lubricating purposes. In particular, the use of boehmite in an aqueous solution significantly reduces frictional coefficients between contacting surfaces.
The present invention uses a high energy x-ray, neutron, or gamma source for monitoring the interface between a molten and solidified crystalline phase while in a furnace in a casting process. The radiation can also be used to determine the quality and orientation of the crystals in the crystalline phase. The invention uses the distinctive diffraction patterns produced by crystalline and amorphous phases to locate the interface.
The change in the peak fluorescence wavelength of a small amount of a fluorescent compound, i.e., a fluorophore, which has been dissolved in a polymerizing material or a thermoplastic polymer is used to determine the extent of cure or solidification, respectively. The measured wavelength-shift can either be compared with a previously determined correlation to obtain an absolute value for the extent of cure, or can be utilized to compare or maintain an acceptable extent of cure throughout a manufacturing or a clinical process. Similarly, in the processing of a thermoplastic polymer by injection molding, the measured wavelength shift can either be compared with a previously determined correlation to obtain an absolute value for the temperature of the polymer, or can be utilized to adjust the injection molding cycle so that the mold is opened at the optimum times. The fluorophores used in the method are preferably selected from a class of fluorophores comprising alpha, omega substituted linear alkenes having an electron accepting group attached at the alpha position and an electron donating group attached at the omega position.
A high lead solder exhibiting improved wettability to metal substrates, an advantageously controlled melting range, and excellent thermal fatigue properties. It comprises about 98-100% lead and a minor amount, typically about 0.0005-0.1 wt %, based on the total weight of the solder composition, of an alkali metal selected from the group consisting of Na, K, and Li. Additional embodiments additionally comprise an amount of a grain-size controlling additive, e.g., 0.001-0.5 wt % (based on the total weight of all the components in the solder composition) selected from the group consisting of Ce, Ba, La, Pr, Nd, Sm, Eu, Gd, Th, Dy, Ho, Er, Tm, Yb, Y, Lu, Sc, Mg, Na, Se, Te, oxides thereof and mixtures thereof, in amount effective to control the Pb grain size; and 0-1 wt % of an element selected from the group consisting of Sn, In, Bi, Sb, Ag, Au, and Ga, and mixtures thereof.
A cabled platform suspension system includes a platform having first and second support points at spaced locations along a front work-access edge of the platform and a third, stabilizing/rotator support point. A platform support structure, such as the two or four towers of a dry dock, defines first, second, third and fourth platform suspension points arranged in a substantially rectangular pattern. Six cables are connected between the platform and support structure, with five cables being respectively connected between the first and fourth suspension points and the first and second platform support points, two cables being respectively connected between the second and third suspension points and the first and second platform support points and two cables being respectively connected between the second and third suspension points and the third platform support point.
The invention describes a crane concept to facilitate the transfer of containerized cargo between two ships at sea. The invention uses a macro/micro design under which a serial set of independently controlled manipulators move a load from a base ship to a target ship. The manipulator mounts on a ship which is moved by the actions of sea and wind. The macro-manipulator is a modified container crane. The modifications compensate for large motions of the base ship. The micro-manipulator moves the load and compensates for the motions of the receiving ship and the unscheduled motions of the base ship remaining after the macro-manipulator compensation.
Methods for electrodepositing a metal-carbon coating on a substrate comprising immersing the substrate in an aqueous electrolyte, and passing a sufficient current through the electrolyte to effect electrolyte deposition of a metal-carbon alloy on the substrate. The aqueous electrolyte comprises from about 0.2 to about 0.6 mol/l of metal ions selected from the group consisting of iron, nickel, nickel-tungsten mixture and cobalt-tungsten mixture, greater than about 1.4 mol/l of an amidosulfonic acid or a salt thereof, ammonium ions, formic acid or a salt thereof, and water.
The dielectric slit die is an instrument that is designed to measure electrical, rheological, ultrasonics, optical and other properties of a flowing liquid. In one application, it is connected to the exit of an extruder, pump or mixing machine that passes liquefied material such as molten plastic, solvents, slurries, colloidal suspensions, and foodstuffs into the sensing region of the slit shaped die. Dielectric sensing is the primary element of the slit die, but in addition to the dielectric sensor, the die contains other sensing devices such as pressure, optical fiber, and ultrasonic sensors that simultaneously yield an array of materials property data. The slit die has a flexible design that permits interchangeability among sensors and sensor positions. The design also allows for the placement of additional sensors and instrumentation ports that expand the potential data package obtained.
The present invention relates to x-ray diffraction measurement by using moving x-ray source x-ray diffraction. The invention comprises a raster-scanned x-ray source, a specimen, a collimator, and a detector. The x-ray source is electronically scanned which allows a complete image of the x-ray diffraction characteristics of the specimen to be produced. The specimen is placed remote from the x-ray source and the detector. The collimator is located directly in front of the detector. The x-rays are diffracted by the specimen at certain angles, which cause them to travel through the collimator and to the detector. The detector may be placed in any radial location relative to the specimen in order to take the necessary measurements. The detector can detect the intensity and/or the wavelength of the diffracted x-rays. All information needed to solve the Bragg equation as well as the Laue equations is available. The x-ray source may be scanned electronically or mechanically. The present invention is used to perform texture analysis and phase identification.
Disclosed is a fluid mixer that mixes liquids while simultaneously promoting rapid mixing entrainment of vapor in the liquid. The device includes a vertical rotor mounted centrally on a base assembly. The rotor comprises a tube which is hollow from an open top end to a bottom closed end, having an external screw thread in a right-side configuration relative from top to bottom and one or more holes located in the sidewall of the tube at the bottom of the hollow portion of the tube, preferably located centrally between two flanking surfaces of the screw thread. The base assembly comprises a stirbar and a supporting disk which contains a ceramic magnet. The base rests on the floor of a containment vessel. A magnetic stirring motor is centrally located sufficiently close to and beneath the containment vessel as to achieve magnetic flux coupling with the base magnet. Operation of the mixer develops a liquid vortex in the liquid phase material. As the speed increases, the external screw threads generate turbulence and draw vapor into the liquid from above the tube and urge the vapor into intimate contact with the turbulent, droplet-forming liquid. A circulation develops causing a vortex to develop. As the speed of circulation increases, the surface of the liquid is lowered until it matches the hole in the sidewall of the tube. The liquid enters the holes in the sidewall of the tube along with entrained vapor, and rises through the liquid in the hollow tube, and exits the open top end.
A method for the removal of carbonyl sulfide from liquefied petroleum is disclosed. Removal of carbonyl sulfide is accomplished by contacting a liquid petroleum gas stream containing a carbonyl sulfide as an impurity with a calixarene complexing agent as the principal agent for the removal of the carbonyl sulfide.
A high-Tc superconductor contact unit having low interface resistivity is disclosed, as is a method for making the unit. An inert metal is deposited on the surface of the superconductor, which surface is preferably non-degraded, to form a unit with the surface of the superconductor, and where temperatures as high as 500°C to 700°C can be tolerated, the unit is oxygen annealed to establish a still lower surface resistivity between the surface of the high-Tc superconductor and the inert metal, including a low surface resistivity of about 10-10 Ω-cm2 at high-Tc superconductor operating temperatures. The superconductor is a metal-oxide superconductor, and may be rare earth, thallium, or bismuth based.
Inspection of objects such as X-ray lithography masks is carried out by passing X-rays or extreme ultraviolet light through an object which absorbs in a pattern to provide a patterned X-ray or ultraviolet image which is then directed to a converter. The converter converts the image incident upon it to an image formed by electrons emitted from the converter. The emitted electrons are magnified in an electron microscope and the magnified electron image is displayed by the electron microscope. The visible image may be further digitized and processed by a computer, including long-term storage or display on a computer monitor. X-ray lithography masks may be inspected by passing X-rays through masks of the same type that will be used for lithography so that the magnified image of the X-rays passed through the masks corresponds to the pattern of X-rays that will be incident on a photoresist, allowing accurate inspection of X-ray masks before use.
A spray pyrolysis method for producing pure metal and/or metal oxide particles uses a mixture of a carrier gas and a solution of a metal salt precursor, water and a co-solvent reducing agent. The metal salt precursors preferably comprise metals from the group consisting of Fe, Co, Ni, Cu, Zn, Pd, Ag and Au, whereas the salt anions preferably comprise nitrates, acetates, oxalates and chlorides. The co-solvents are those that act as a reducing agent, are vaporizable, are inert with respect to the carrier gas, and are hydrophilic, such as alcohols, in particular, low-carbon numbered alcohols such as methanol or ethanol.
A cable-driven manipulator can precisely manipulate tools and loads using position, velocity and force control modes. The manipulator includes a plurality of cables (2 or more) that are independently controlled by modular, winch drive-mechanisms and coordinated to achieve intuitive manipulator movement in all six degrees-of-freedom. The manipulator consisting of modular sub-assemblies and components (i.e. winch, amplifier, servo interface, sensory feedback), can be rapidly reconfigured to adjust to new applications. Various combinations of manual and automatic control can also be implemented. The winches can be controlled manually by a multi-axis joystick, or can be automatically controlled by computer.
A positioning device and method for positioning objects is provided. The device includes a movable stage and a pair of levers. The pair of levers is symmetric about a first axis of the movable stage. Additionally, the pair of levers is parallel to a second axis of the movable stage. This second axis is perpendicular to the first axis. Each of the pair of levers applies a force to the movable stage. Each of the pair of levers moves in an arc. The two levers move in opposite directions along their respective arc. The two arcs are symmetrical about an axis of the movable stage.
A position detector for sensing the position of a movable member which moves along an axis relative to a stationary member. A nonrepeating N bit chain code embodied in a scale on the movable member runs along the axis. A detector fixed to the stationary member is positioned to sense a portion of the chain code. The detector has K elements (K>>N) generating a plurality of signals. A controller determines the position of the movable member relative to the stationary member as a function of the signals.
A spatial RAM system uses the position of a data sensor to generate a clock pulse that is used to trigger data acquisition. As a consequence, the errors associated with time-based clock sampling are avoided. This enables more accurate sampling of data at locations desired in space and more easily allows for non-uniform sampling.
The invention relates to a three-dimensional measuring device, comprising a rotating 360 degree sensor head, a laser scanner and an extendable mast system. The sensor head contains a 360 degree rotating multi-faceted mirror, which determines total path distance from the laser scanner to a particular target. Angular orientations on both the scanner and the faceted mirrors are calculated by a precision encoding system. The measured total path distance, mast system extension, scanner head rotation, mirror rotation angles, and mast deflection are all used to calculate the location of a target point in 3-D space relative to the scanner. The sensing device can be utilized in the construction and nuclear power areas. In the nuclear power area, the mast system can be extended into a contaminated area which the sensor remains outside the contaminated area, thereby avoiding contamination problems.
A method for the chemical precipitation of metallic silver powder employs a two solution technique in which a solution of a tin salt and a solution a silver salt are mixed in the presence of an inorganic or organic acid, alumina, an anionic surfactant, and a colloid to form a precipitation solution at a temperature and pH suitable to effect the chemical precipitation of silver. Almost 80% by weight of the precipitated powder agglomerate is less than 25 µm in diameter, and the individual powder particles which compose the agglomerate range in size from 0.2 to 2.0 µm. In addition to the favorable size distribution, silver particles precipitated in the presence of a gelatin colloid can be used with a minimal amount of sieving so that little work hardening is imparted to the particles. The powder can be annealed at a temperature of up to 750° C. for two hours in air with minimal sintering, and the acid-assisted hand consolidation of powder produced according to the present technique is capable of producing silver compacts which are nearly 80% dense. Advantageously, a hand consolidated silver compact which comprises the powder of the present invention equals or exceeds the transverse rupture strength, shear strength, creep, toughness, corrosion resistance, microleakage, and wear properties of conventional silver amalgam.
A positioning device and method for positioning objects is provided. The device includes a movable stage and a pair of levers. The pair of levers is symmetric about a first axis of the movable stage. Additionally, the pair of levers is parallel to a second axis of the movable stage. This second axis is perpendicular to the first axis. Each of the pair of levers applies a force to the movable stage. Each of the pair of levers moves in an arc. The two levers move in opposite directions along their respective arc. The two arcs are symmetrical about an axis of the movable stage.
This document describes a method for bonding two or more objects using nanometerscale to micrometer-scale adhesive particles manipulated and cured by optical tweezers, including holographic optical tweezers.
A system and method for bonding and unbonding of small objects using small adhesive particles. The system and method includes the use of a plurality of optical tweezers to manipulate objects to be bonded and adhesive particles suspended in a fluid. The objects to be bonded (or unbonded) and the adhesive particles are positioned by lower power optical tweezers and then an intense bonding optical tweezer is activated to cause the adhesive to join the objects together (or used to unbond objects).
Apparatus and method for integrating lasers and optics on glass substrates. An optical (e.g., laser) component formed from a glass substrate doped with a optically active lanthanides species with a plurality of waveguides defined by channels within the substrate. The laser component optionally includes a monolithic array of individual waveguides in which the waveguides form laser resonator cavities with differing resonance characteristics. Another aspect is directed toward pumping the laser wherein a superstrate waveguide cavity, or cladding, Ls positioned adjacent the substrate waveguide for supplying the latter with pump light. A closed crucible processing of optical waveguides on a glass substrate is also described. Waveguides are created by exposing a surface of the substrate to an ion-exchange solvent (e.g., a molten salt). A tightly sealed multi-part crucible is provided in order that gas does not leak in or out of the crucible during cooling or heating of the system.
This invention consists of a bias and readout scheme for resistive bolometers. It is chiefly intended for use with bolometer materials which exhibit a phase transition that is hysteretic. A preferred bolometer material is vanadium dioxide, which has a metal-semiconductor phase transition at 68° C. and a hysteresis of typically 5° C., depending on material preparation. The existence of hysteresis precludes the use of a conventional dc bias or a conventional pulsed bias in a bolometer operated on the phase transition. In the present method, the bias consists of an ac current for phase transitions in which the resistance decreases with increasing temperature. For phase transitions in which the resistance increases with temperature, an ac voltage bias would be used.) The waveform of the ac bias consists of a short "reset" segment in which the peak current is high enough to bring the bolometer completely into its metallic state, followed by a longer "data" segment in which the bias current and bias power monotonically decrease, so as to sweep the bolometer's physical temperature downward across the phase transition. The frequency of the ac bias is determined by the condition that the slew rate in bias power during the data segment must always exceed the slew rate in signal power, for all signals of interest. The signal is read out by averaging the bolometer voltage over a time window lying entirely within the data segment. With this bias and readout scheme, the full slope of the bolometer R(T) characteristic is reflected in the output from small signals, which would not be the case for a conventional dc or pulsed bias scheme. Since the full slope of the R(T) characteristic is accessible, the bolometer can operate in the extreme electrothermal feedback regime, which provides major improvements in speed, 1/f-noise, and sensitivity.
A Gd.sub.5Ge.sub.2Si.sub.2 refrigerant compound is doped or alloyed with an effective amount of silicide-forming metal element such that the magnetic hysteresis losses in the doped Gd.sub.5Ge.sub.2Si.sub.2 compound are substantially reduced in comparison to the hysteresis losses of the undoped Gd.sub.5Ge.sub.2Si.sub.2 compound. The hysteresis losses can be nearly eliminated by doping the Gd.sub.5Ge.sub.2Si.sub.2 compound with iron, cobalt, manganese, copper, or gallium. The effective refrigeration capacities of the doped Gd.sub.5Ge.sub.2Si.sub.2 compound are significantly higher than for the undoped Gd.sub.5Ge.sub.2Si.sub.2 compound.
A parallel nanotomography imaging system is provided having an x-ray source, which is preferably a laser-based x-ray source that generates x-rays that are collected using a collector optic and are received in a composite objective assembly. The composite objective assembly includes plural micro-objectives, each imaging the target. The x-ray image is received by an x-ray image formation and acquisition apparatus, and processed and/or displayed.
In this disclosure, we present a widely applicable technique which enables two (or more) mechanically independent structures (e.g. an atomic force microscopy (AFM) tip and a reference mark on the sample substrate) whose respective positions in three dimensional space can be maintained with sub-nanometer precision for long (~100 s) periods of time. The method is based on the scattering of laser light by one (or more) fiducial marks. One mark is coupled to each structure to be positioned, except in the case where a lens is one of the structures to be stabilized. The scattered light is collected in a photo-sensitive device which enables real-time high-bandwidth position-sensing of each structure. The method requires one of the structures to be mounted onto a precision (e.g. piezoelectric) 2D or 3D translational stage. Signals generated by the scattered light field are used in a feedback loop to modulate the stage position. The technique presented here could potentially find utility across a number of disciplines including: optical tweezers, optical microscopy, scanning probe microscopy and semiconductor pattering and processing.
A method of imaging critical dimensions by measuring the zeroeth order of diffracted light. The method involves providing a target, directing light onto the target so as to cause the target to diffract the light. The zeroeth order of the diffracted light is collected and analyzed to determine structural features of the target. The target can be an article of manufacture, such as a semiconductor device, or a separate target that is provided or fabricated on an article of manufacture. One of at least the wavelength and the angle at which the light is directed onto the target can be scanned. The target can fill all or only a portion of the field of view.
A zero-order overlay target comprises a first zero-order line array fabricated on a first layer of a semiconductor structure, the first zero-order line array having a first pitch, and a second zero-order line array fabricated on a second layer of the semiconductor structure, the second zero-order line array having a second pitch. The second pitch may be different from the first pitch, and a portion of the second zero-order line array may be positioned to become optically coupled to a portion of the first zero-order line array when subject to an overlay measurement. Further, the second pitch may be variable. For example, the variable pitch may comprise a first set of features having a pitch approximately equal to the first pitch, a second set of features having a pitch different from the first pitch, and a third set of features having a pitch approximately equal to the first pitch.
Highly Charged Ion Modified Oxides (HCIMO) are achieved by irradiating a thin, high resistance oxide with highly charged ions (HCIs) and then depositing a conducting material of choice on top the irradiated oxide. The irradiation by HCIs preferentially ablates a region on the order of a cubic nanometer at each HCI’s impact site breaking a hole through the ultra-thin oxide. This is demonstrated by the inventors by preparing an insulating layer of aluminum oxide on a cobalt lower electrode layer, exposing the oxide to very dilute HCI radiation, and then depositing a cobalt upper layer. The data show a clear and systematic decrease in the resistance of the multilayer devices correlated to the HCI dose at very dilute doses, i.e., an HCI density of 100 HCIs/ìm2 (108 HCIs/mm2) yields a resistance reduction by a factor of greater than 100. The nanometer dimensions of individual HCI impacts and the precise control over the dose combine to allow high precision selection of the material’s resistance over a wide range of values, currently demonstrated over three orders of magnitude.
As HCI modification only occurs within a few nanometers of the surface and generally does not affect metals, no special measures are needed to protect surrounding device structures from HCI damage. Since the size of the material modification is determined by the properties of a single ion, precise alignment is not required, only uniform illumination of the device area by the HCI beam, greatly simplifying commercial integration of HCI irradiation.
We have further employed this strategy of producing an ensemble of small, discrete pockets of one material within another using HCIs to produce a new type of magnetic sensor. This approach may provide a solution to the current perpendicular to the plane (CPP) magnetic sensor resistance problem. In that problem, state-of-the-art CPP type magnetic sensors produced by using metal-metal interfaces or metal-insulator interfaces lead to resistances too low or too high, respectively, to be commercially viable. By using HCIMO as the buffer material instead of a metal (as in giant magneto-resistance [GMR] type sensors) or an insulator (magnetic tunnel junction [MTJ] type sensor) we can produce devices with the desired resistance values needed for advanced magnetic sensors for future hard drive read heads.
By using HCIMO as the buffer layer in a magnetic multilayer structure, we are creating a new type of sensor that uses a superposition of metal-insulator and metal-metal sensor junctions at a controlled density without advanced fabrication techniques. Magnetic sensitivity in this new type of device has also been demonstrated with evidence that both the metal-insulator and metal-metal parts of the HCIMO type sensors produce a clearly measurable response to small external magnetic fields.
A new approach towards electrically contacting the top of an aligned nanowire or nanotube array using a conductive nanoparticle film has been developed. This contact method allows surfaces along the length of the nanowire or nanotube to remain untreated. Previously the only way to attach electrical contacts to the non-substrate ends of vertically oriented nanowires or nanotubes involved attempts at filling the spaces between the nanorods with some material. This would be followed by some kind of electro-polish to expose the top ends of the nanorods, over which a continuous film would be developed. In such a process contamination of the nanorods by the fill material, and contamination at the metal. contact interface posed problems. In the new approach, only the contact material is present. Briefly, conducting nanoparicles (metals such as gold, silver etc.) are generated, charged and deposited onto the sample containing the nanowire or nanotube array within an electrostatic precipitator. The electric field enhancement from the tips of the nanowires (or nanotubes) is utilized to attract charged nanoparticles exclusively onto the top of the array. The result is an array of standing nanorods with a continuous and porous top contact layer.
A new approach towards electrically contacting the top of an aligned nanowire or nanotube array using a conductive nanoparticle film has been developed. This contact method allows surfaces along the length of the nanowire or nanotube to remain untreated. Previously the only way to attach electrical contacts to the non-substrate ends of vertically oriented nanowires or nanotubes involved attempts at filling the spaces between the nanorods with some material. This would be followed by some kind of electro-polish to expose the top ends of the nanorods, over which a continuous film would be developed. In such a process contamination of the nanorods by the fill material, and contamination at the metal. contact interface posed problems. In the new approach, only the contact material is present. Briefly, conducting nanoparicles (metals such as gold, silver etc.) are generated, charged and deposited onto the sample containing the nanowire or nanotube array within an electrostatic precipitator. The electric field enhancement from the tips of the nanowires (or nanotubes) is utilized to attract charged nanoparticles exclusively onto the top of the array. The result is an array of standing nanorods with a continuous and porous top contact layer.
A thermometer is provided. A housing has at least one opening. A dielectric element is disposed in the housing. At least one microwave guide is coupled to the at least one opening for providing a signal into the dielectric element for propagation at a resonant frequency and for receiving the signal from the dielectric element. A temperature determination unit receives the signal from the at least one microwave guide, measures the resonant frequency of the dielectric element, and determines the temperature of the dielectric element based on a relationship between resonant frequency and temperature of the dielectric element.
A method for microfabrication of a microfluidic device having sub-millimeter three dimensional relief structures is disclosed. In this method, homogeneous surfaces, which do not exhibit apparent pixel geometry, emerge from the interaction of the overlapping of diffracted light under opaque pixels and the nonlinear polymerization properties of the photoresist material. The method requires a single photolithographic step and allows for the fabrication of microstructures over large areas (centimeters) with topographic modulation of features smaller than 100 micrometers. The method generates topography that is useful in a broad range of microfluidic applications.
Embodiments of the present invention provide an inexpensive and fast pulse characterization platform capable of real time operation, suitable for acquisition of single-photon data. Embodiments of the present invention include both a digital multi-channel data acquisition instrument and an analog pulse acquisition instrument suitable for a wide range of applications in physics laboratories. An FPGA performs multi-channel acquisition in real time, time stamps single events and determines if the events fit a predetermined signature, which causes the events to be categorized as a coincidence. The indications of coincidences are then communicated to a host computer for further processing as desired.
This invention consists of a new source for creating a focused ion beam. A magneto-optical trap serves as a source of cold atoms that are photo ionized to produce the ion source. Under appropriate conditions, the resulting ion cloud has temperature and spatial characteristics similar to that of the initial neutral atom cloud. An external electric field extracts the ions which can be focused using standard charged-particle optics. The cold temperatures achieved through laser cooling yield an ion beam with excellent characteristics which should allow for a beam resolution of 10 nm or less. The current produced from this source depends on the operating parameters of the MOT and can range from single ions on demand to over 100 pA, a much wider range than is currently possible. In addition, the wide range of elements that can be laser cooled greatly extends the possibilities for ionic species that can be used in FIBs, The net result is a source that has improved characteristics as well as expanded capabilities over current technology.
A method of harvesting carbon nanotubes (CNTs) is provided. According to this method, CNT bundles, comprising CNTs associated with metallic catalysts and having amorphous carbon coatings are agitated in an aqueous liquid containing a dispersant with free-flowing grit particles to disassociate the CNTs from the metallic catalysts, remove the amorphous carbon of the amorphous carbon coatings and shorten the CNTs via shearing.
Superconformat Metal Deposition Using Derivitized Substrates: Docket # 02-011
The process of this invention involves first adsorbing a catalyst on the surface of a specimen by immersion in a catalyst-containing solution, followed by electrolytic deposition in a second solution that need not contain catalyst. This two-step superconformal process produces a seam-free and void-free metal microelectronic conductor.
Towards Industrial Scale-Fabrication of Nanowire-Based Devices: Docket # 08-001
The invention deals with the challenge of void-free filling of recessed surface features on non-planar metalized surfaces with iron group magnetic materials. Specifically, the addition of certain benzimidazole derivatives to a conventional additive-free nickel plating baths, e.g. Watts bath NiS04-NiCli, results in a superconformal deposition growth mode. By superconformal deposition we mean that metal deposition occurs preferentially in recessed surface features, such as patterned trenches and vias, thereby resulting in void-free filling. By appropriate patterning and design a variety of fully consolidated 3-D shapes and geometries can be fabricated. The resulting structures have potential use as micromagnets for microelectromechanical devices as well as active magnetic material components for use in a variety of information storage devices. The process may also be useful in the deposition of Ni and related metals as a precursor to forming silcide contacts in microelectronics.
This invention allows control over the location and direction of nanowires on a large size single crystal wafer.
A laser Doppler vibrometer for vibration measurement that employs active feedback to cancel the effect of large vibration excursions at low frequencies, obviating the need to unwrap phase data. The Doppler shift of a reflective vibrating test object is sensed interferometrically and compensated by means of a voltage-controlled oscillator driving an acousto-optic modulator. For frequencies within the servo bandwidth, the feedback signal provides a direct measurement of vibration velocity. For frequencies outside the servo bandwidth, feedback biases the interferometer at a point of maximal sensitivity, thus enabling phase-sensitive measurement of the high-frequency excursions. Using two measurements, one with a low bandwidth and one with a high bandwidth, more than five decades of frequency may be spanned. This approach is of particular interest for the frequently occurring situation where vibration amplitudes at low frequency exceed an optical wavelength, but knowledge of the vibration spectrum at high frequency is also important.
A nanofabrication Process for use with a photoresist that is disposed on a substrate includes the steps of exposing the photoresist to a grayscale radiation pattern, developing the photoresist to remove the irradiated portions and form a patterned topography having a plurality of nanoscale critical dimensions, and selectively etching the photoresist and the substrate to transfer a corresponding topography having a plurality of nanoscale critical dimensions into the substrate.
A National Institute of Standards and Technology (NIST) researcher has come up with a method designed to improve the energy efficiency of water chillers that cool the nation’s large commercial buildings. The NIST method, if confirmed through experiments with full-scale chiller systems, could save as much as 1 percent of the 320 billion kWh of electricity used annually by chillers or an equivalent 5.5 million barrels of oil per year, according to Mark Kedzierski, the NIST mechanical engineer who developed the technique.
An optical method with the potential to discriminate between changes in the physical parameters of a target as represented in the properties of light scattered off of the target. For example, whether a change in the scattered light is due to a change in the height or width of a line.
We invent and demonstrate a qualitatively new form of cavity ringdown
spectroscopy utilizing a broad bandwidth optical frequency comb coherently
coupled to a high finesse optical cavity inside which molecular samples are located.
125,000 optical comb components, each coupled into a specific longitudinal cavity
mode, undergo ring down decays when the cavity input is shut off This provides
sensitive intracavity absOlption information simultaneously available across 100
nm in the visible and near IR spectral region. By placing various atomic and
molecular species (Ar, C2H2, O2, H20, NH3) inside the cavity, we demonstrate realtime,
quantitative measurements of the trace presence, transition strengths and
linewidths, and population redistributions due to collisions and temperature
changes. This novel capability to sensitively and quantitatively monitor multispecies
molecular spectra over a large optical bandwidth in real-time provides a
new spectroscopic paradigm for studying molecular vibrational dynamics, chemical
reactions, and trace analysis.
A stationary phase for a liquid chromatography and process for making is provided. The stationary phase material may have a modified base substrate and a fluorinated carboxylic acid covalently bonded thereto through an amide or ester bond. The stationary phase may have a substantially consistent shape selectivity characteristic with an .alpha..sub.TBN/BaP of less than 1 within a temperature range of at least 10-70.degree. C. Advantageously, a fluorinated stationary phase has a shape selectivity characteristic exhibited with an .alpha..sub.TBN/BaP of less than 1 with a mobile phase having up to at least 30% water. A process for making the stationary involves mixing a substrate material or fluorinated carboxylic acid with a reactive alkylsilane linker and at least one organic solvent to form a first solution. The other of the substrate material or fluorinated carboxylic acid is then added to the first solution, or to a product separated from the first solution, to form a second solution. The second solution is reacted to form the stationary phase.
Here we introduce a technique which allows sharp objects (e.g. scanning tunneling microscope tips, atomic force microscope tips, near-field scanning optical microscope tips, pipette tips, etc.) to be rapidly brought into close proximity to a particular region of a surface with high precision and accuracy in three dimensions. The method has potential applications in a broad array of tip-based research instrumentation and manufacturing techniques, including: scanning probe microscopy, atomic force microscopy, proximal probe lithography, dip-pen lithography, tip-indent lithography, molecule array manufacturing, and single atom manipulation.
In a typical atomic force microscope, course approach between tip and sample is achieved via a translation by a long range (0.1-1000 microns) stage followed by a fine stage movement (0.1-1000 nm); if the surface is not found, this process is repeated. Often, optical microscopes are used to aid in this process. Prior art does not allow registered tip approach due to the lack of a reliable method to yield precise three dimensional simultaneous localization of a tip and a sample surface. This knowledge is necessary in order to bring these objects into close proximity or contact with high resolution registration and speed.
A coherent laser radar that uses two coherent femtosecond fiber lasers to perform absolute ranging at long distance. One coherent femtosecond fiber lasers acts as a source and the other as a local oscillator for heterodyne detection of the return signal from a cooperative target. The system simultaneously returns a time-of-flight range measurement for coarse ranging and an interferometric range measurement for fine ranging which is insensitive to spurious reflections that can cause systematic errors. The range is measured with at least 3 μm precision in 200 μs and 5 nm precision in 60 ms over a 1.5 m ambiguity range. This ambiguity range can be extended to 30 km through reversal of signal and LO source roles.
A method of comb-based spectroscopy with synchronous sampling for real-time averaging includes measuring the full complex response of a sample in a configuration analogous to a dispersive Fourier transform spectrometer, infrared time domain spectrometer, or a multiheterodyne laser spectrometer. An alternate configuration of a comb-based spectrometer for rapid, high resolution, high accuracy measurements of an arbitrary cw waveform.
Mixing Reactions by Temperature Gradient Focusing: Docket # 01-029CIP1
A method is provided for observing mixing interactions and reactions of two materials in a fluid. The method in one form provides for concentrating by balancing electrophoretic velocities of a material against the bulk flow of fluid in the presence of a temperature gradient. Using an appropriate fluid, the temperature gradient can generate a corresponding gradient in the electrophoretic velocity of the material so that the electrophoretic and bulk velocities sum to zero at a unique position and the material will be focused at that position. A second material can then be introduced into the fluid and allowed to move through and interact with the focused band of the first material. Products of the interaction can then be detected as they are focused at a different position along the gradient. The method can be adapted to study the temperature dependence of the molecular interaction.
Fluidic Temperature Gradient Focusing: Docket # 01-029
The present invention concerns a method and device for concentrating and separating ionic species in solution within fluid conduits which include channels, microchannels and capillary tubes. The concentration is achieved by balancing the electrophoretic velocity of an analyte against the bulk flow of solution in the presence of a temperature gradient. Unlike previous methods, such as salt bridges or electrodes, which severely limit the type of analyte that can be concentrated, this invention can be adapted for use with any charged analyte, including fluorescent dyes, amino acids, proteins, DNA, cells and particles. Additionally, the use of a temperature gradient prevents the need for an electric field gradient which tends to be difficult to construct and require a control of voltage on an additional electrode. Finally, this invention can be used to achieve higher degrees of sample concentration, which can provide up to or, in some instances, exceed a 10,000-fold concentration of a dilute analyte.
Chiral Temperature Gradient Focusing: Docket # 01-029CIP2
The present invention combines the high resolution of chiral capillary electrophoresis with the high concentration enhancement and low detection limits of temperature gradient focusing. The temperature gradient focusing allows for higher degrees of sample concentration, such as more than a 10,000 fold concentration of a dilute material, when compared with any prior single sample preconcentration method. Additionally, the electrophoretic velocity gradient is formed in response to the temperature gradient without the need for externally manipulated voltages or complicated and difficult to fabricate semi-permeable structures. Finally, the present invention is able to separate stereoisomers of a material which have different affinities for the additive. Essentially, with the addition of a chiral additive, the present focusing method allows for simultaneous separation and concentration of materials that cannot be separated using temperature gradient focusing based purely upon their electrophoretic mobilities. One benefit of being able to separate chiral stereoisomers is that many drugs and drug candidates are chiral and in most cases, one stereoisomer is more desired for drug use than the other. In some instances, one stereoisomer is a beneficial drug, whereas the other results in adverse side effects.
Chiral Temperature Gradient Focusing: Docket # 01-029CIP2
The present invention combines the high resolution of chiral capillary electrophoresis with the high concentration enhancement and low detection limits of temperature gradient focusing. The temperature gradient focusing allows for higher degrees of sample concentration, such as more than a 10,000 fold concentration of a dilute material, when compared with any prior single sample preconcentration method. Additionally, the electrophoretic velocity gradient is formed in response to the temperature gradient without the need for externally manipulated voltages or complicated and difficult to fabricate semi-permeable structures. Finally, the present invention is able to separate stereoisomers of a material which have different affinities for the additive. Essentially, with the addition of a chiral additive, the present focusing method allows for simultaneous separation and concentration of materials that cannot be separated using temperature gradient focusing based purely upon their electrophoretic mobilities. One benefit of being able to separate chiral stereoisomers is that many drugs and drug candidates are chiral and in most cases, one stereoisomer is more desired for drug use than the other. In some instances, one stereoisomer is a beneficial drug, whereas the other results in adverse side effects.
Fluidic Temperature Gradient Focusing: Docket # 01-029
The present invention concerns a method and device for concentrating and separating ionic species in solution within fluid conduits which include channels, microchannels and capillary tubes. The concentration is achieved by balancing the electrophoretic velocity of an analyte against the bulk flow of solution in the presence of a temperature gradient. Unlike previous methods, such as salt bridges or electrodes, which severely limit the type of analyte that can be concentrated, this invention can be adapted for use with any charged analyte, including fluorescent dyes, amino acids, proteins, DNA, cells and particles. Additionally, the use of a temperature gradient prevents the need for an electric field gradient which tends to be difficult to construct and require a control of voltage on an additional electrode. Finally, this invention can be used to achieve higher degrees of sample concentration, which can provide up to or, in some instances, exceed a 10,000-fold concentration of a dilute analyte.
Mixing Reactions by Temperature Gradient Focusing: Docket # 01-029CIP1
A method is provided for observing mixing interactions and reactions of two materials in a fluid. The method in one form provides for concentrating by balancing electrophoretic velocities of a material against the bulk flow of fluid in the presence of a temperature gradient. Using an appropriate fluid, the temperature gradient can generate a corresponding gradient in the electrophoretic velocity of the material so that the electrophoretic and bulk velocities sum to zero at a unique position and the material will be focused at that position. A second material can then be introduced into the fluid and allowed to move through and interact with the focused band of the first material. Products of the interaction can then be detected as they are focused at a different position along the gradient. The method can be adapted to study the temperature dependence of the molecular interaction.
Gradient elution moving boundary electrophoresis (GEMBE) is a recently described technique for electrophoretic separations in short (1-3 cm) capillaries or microchannels. With GEMBE, the electrophoretic migration of analytes is opposed by a bulk counterflow of separation buffer through the separation channel. The counterflow velocity is varied over the course of a separation so that analytes with different electrophoretic mobilities enter the separation channel at different times and are detected as moving boundary, stepwise increases in the detector response. The infinite analysis is technology is an implementation of the GEMBE technique in which a very short (0.03-3.5 mm) capillary or microchannel is used as both the separation channel and a conductivity detection cell. Because the channel is so short, only a single moving boundary “step” is present in the channel at any given time, and the measured current through the channel can therefore be used to give a signal comparable to what is normally generated by more complicated detector arrangements.
A Gd.sub.5Ge.sub.2Si.sub.2 refrigerant compound is doped or alloyed with an effective amount of silicide-forming metal element such that the magnetic hysteresis losses in the doped Gd.sub.5Ge.sub.2Si.sub.2 compound are substantially reduced in comparison to the hysteresis losses of the undoped Gd.sub.5Ge.sub.2Si.sub.2 compound. The hysteresis losses can be nearly eliminated by doping the Gd.sub.5Ge.sub.2Si.sub.2 compound with iron, cobalt, manganese, copper, or gallium. The effective refrigeration capacities of the doped Gd.sub.5Ge.sub.2Si.sub.2 compound are significantly higher than for the undoped Gd.sub.5Ge.sub.2Si.sub.2 compound.
This invention is a system for producing a charged particle beam from a photoionized cold atom beam. A vapor of neutral atoms is generated. From these atoms, an atom beam having axial and transverse velocity distributions controlled by the application of laser light is produced.The produced atom beam is spatially compressed along each transverse axis, thus reducing the cross-sectional area of the produced beam and reducing a velocity spread of the produced beam along directions transverse to the beam’s direction of propagation. Laser light is directed onto at least a portion of the neutral atoms in the atom beam, thereby producing ions and electrons. An electric field is generated at the location of the produced ions and electrons, thereby producing a beam of ions traveling in a first direction and electrons traveling in substantially the opposite direction. A vacuum chamber contains the atom beam, the ion beam and the electron beam.