The National Institute of Standards and Technology (NIST) places emphasis on Lab-to-market (L2M) or transfer of NIST intellectual property - original technologies, inventions, and methods (IP) to business and industry. Below is a list of FY 18 patents. A complete list of NIST patents is available for review at the Federal Laboratory Consortium (FLC): https://www.federallabs.org/labs/national-institute-of-standards-and-technology-nist-0.
Please contact our Senior Patent Officer, Dr. Donald Archer, to inquire about licensing NIST patents.
|Patent No.||Title||Description||Inventor||Expiration Date|
|9,983,102||AERODYNAMIC SHOE SAMPLING SYSTEM||
Terrorist and other criminals who come into contact with certain contraband are likely to become contaminated by trace deposits of those contraband materials through active or passive transfer of these chemical compounds. Identification of these chemical compounds and individuals will allow authorities to screen for terrorist and narcotic traffickers more effectively.
Of particular concern to law enforcement authorities is the concealment of explosives in shoes at inspection points for entry into government and military installations; this type of concealment has led to the requirement for all airline passengers to have their footwear removed and screened. Sampling footwear without removal could lead to improvements with passenger compliance and elimination of long security check point lines. Aerodynamic sampling of people, cargo, and other objects is an emerging technology.
Devices that apply aerodynamic sampling to remove trace particles from target surfaces exist but do not ensure that all dislodged particles are transported efficiently to a collector; therefore, such devices are ineffective at maximizing the transport efficiency of particulate matter once they are liberated from surfaces due to loss or spillage out of the sampling system.
The “Aerodynamic Shoe Sampling System” is an improved “front end” extraction portion of a chemical collection apparatus that minimizes spillage or washout of the sample during collection from the targeted surface. It uses high-pressure air jets and knives effectively to remove small particles of explosives, narcotics and other chemical agents from target footwear surfaces without the need for physical contact. The liberation of these chemicals eliminates sample loss through methods that use a physical device for particle abstraction such as brushes or wipe cloths even if the trace compounds are greasy, oily, and/or sticky.
|Lukow, Stefan; Staymates, Matthew E.||2/9/2035|
|9,921,174||SYSTEMS AND METHODS FOR CONTROLLING TEMPERATURE OF SMALL VOLUMES||
The equilibrium state of a chemical or biological system is determined by many physical and chemical variables. Changes in one or more of these variables drive the system into a new steady state. Measurement of relaxation times provides information about the underlying properties of the system. Historically, the ability to perturb large ensembles of molecules from equilibrium led to major advances in understanding reaction mechanisms in chemistry and biology. Today, the behavior of molecules along reaction pathways and the inter- and intra-molecular dynamics are best obtained using single molecule measurement techniques.
A less explored methodology involves isolation of the thermodynamic perturbation (e.g., temperature, pressure, chemical binding) on a single molecule and the subsequent observation of that same molecule. The methodology uses plasmonic nanostructures, a nanopore, and laser light for controlling and/or measuring temperature of small volumes to analyze polymers or other molecules by coupling plasmonic structures (e.g., metallic nanoparticles or other nanostructures) adjacent to a single nanometer-scale protein ion channel or nanopore. Visible laser light incident on the nanoparticles causes a rapid and large increase of the solution temperature, which is measured by the change in the nanopore ionic conductance. The temperature shift affects the ability of individual molecules to enter into and interact with the nanopore.
The difficulties and drawbacks associated with previously known practices are addressed using this methodology. It represents the ultimate sensitivity in reaction measurements because the methodology isolates the internal degrees of freedom of a single molecule. It resolves the issue of measuring “immeasurably fast” diffusion-controlled reactions and enables precise control, measurement, and use of rapid temperature changes of fluid volumes that are commensurate with the size of single molecules. Additionally, it can significantly improve sensor systems and force measurements based on single nanopores, thereby enabling a method for single molecule thermodynamics and single molecule kinetics. Finally, this regime can be modified in such a way to measure temperature at a nanopore; analyze polymers; and calculate the temperature of polymers without departing from producing ultimate sensitivities in reaction measurement.
|Kasianowicz, John J.; Robertson, Jospeh W. F.; Reiner, Joseph E.; Burden, Daniel; Burden, Lisa K; Balijepalli, Arvind||11/14/2033|
|9,828,677||ARTICLE AND PROCESS FOR SELECTIVE ETCHING||
The ability to affordably fabricate complex 3D geometry on the nanoscale is critical to the development and commercialization of numerous emerging technologies. For example, technologies such as chiral photonics for advanced communication and nanofluidics for Lab-on-a-Chip applications benefit from the fabrication and integration of 3D nanostructures. Additionally, any nanofabrication technique suitable for commercial manufacturing must exhibit a high degree of within-wafer uniformity and wafer-to-wafer repeatability.
Unfortunately, nanofabrication techniques that scale economically for commercial applications are typically limited to fabricating either 1D or 2D structures with a high degree of geometric control and 3D structures with little geometric control. These limitations restrict the impact of nanotechnology. Fabricating large arrays of 3D structures in an affordable, scalable manner are needed.
Metal-assisted Chemical Etching (MaCE) of silicon has recently immerged as a new technique capable of fabricating arrays of reasonably complex 3D geometry in a single lithograph/etch cycle. Example structures include chiral 3D spiraling structures, spiraling nanopillars, vertically aligned thin-film metallic nanostructures, sub-surface curved nanohorns, and zig-zag nanowires. The ability of MaCE to fabricate 3D structures results from a unique etching process in which the object that defines the etch profile travels with the etch front, enabling extremely tight feature resolution over the entire etch length.
Currently, a liquid-phase MaCE (LP MaCE) is being used; however, it faces a number of challenges that could block it from being commercially viable. Specifically, fluid flow over the catalyst, which occurs when the etchant solution is introduced onto or removed from the substrate, can induce unwanted catalyst motion. As a result, controlling the etching path with the consistency necessary for large volume manufacturing is challenging, especially when attempting to etch structures across an entire wafer. LP MaCE generates H2 gas bubbles under most catalyst/etchant, resulting in non-uniform etching across a sample due to lower etch rates under the bubble. Additionally, LP MaCE relies on catalyst motion to define the etch path. For large wafers the flow of the etchant over the substrate can induce undesirable catalyst motion.Instead of using LP MaCE, this technology uses vapor phase MaCE (VP MaCE) as a way to bypass some of the processing challenges found LP MaCE. VP MaCE has shown to improve the controllability and repeatability of MaCE while maintaining the high feature resolution and 3D nanofabrication capabilities of LP MaCE, but eliminating the problems associated with fluid flow and fluid-based processes. Additionally, VP MaCE enables tighter control over etching path and length and reduces process stop-lag (time between when you remove the etchant to when the etching process actually stops).
|9,809,882||ARTICLE AND PROCESS FOR SELECTIVE DEPOSITION||
Currently, a density gradient in silicon can be made by deep reactive ion etching or dicing a silicon wafer with a dicing saw. However, these methods provide a relatively course gradient and are not suited for creating a density gradient in a curved surface. Additionally, chemical vapor deposition process operates under harsh chemical environments, including high temperatures, high energy plasmas and dangerous gasses. These harsh conditions limit what type of substrates can be used and increase cost. Therefore, a new method for providing density gradients in materials has been developed utilizing a deposition of metal as follows:
disposing an activating catalyst on a substrate;
contacting the activating catalyst with a metal cation from a vapor deposition composition;
contacting the substrate with a reducing anion from the vapor deposition composition;
performing an oxidation-reduction reaction between the metal cation and the reducing anion in a presence of the activating catalyst; and
forming a metal from the metal cation to deposit the metal on the substrate.
The advantages to using this process are:
deposition occurs under low temperature, benign chemical environments
chemical precursors are cheap and readily available
reaction chamber is cheaper than traditional chemical vapor deposition chambers
site selective deposition
can fill ultra-small openings
do not have to worry about wetting properties of substrate
void free filling for micro-via applications
easily fabricate 3D metallic nanostructures
wide range of metal precursors
carbon free metals
|9,903,808||MULTI-HETERODYNE DETECTION WITH DUAL OPTICAL FREQUENCY COMBS GENERATED FROM CONTINOUS-WAVE LASERS||
This technology offers a new frequency continuous-wave method to overcome limitations from traditional methods used in spectroscopy. Currently, femtosecond optical frequency combs (FOFCs) generated from mode-locked pulsed lasers (MLL) offer a wide spectral bandwidth and ultra-narrow frequency component linewidths while serving as absolute frequency references when phase stabilized. However, there are limitations to this process including:
Due to the wide bandwidth of FOFCs, in some cases each frequency component has nanowatts or less of optical power that might limit ultimate sensitivity and use in spectroscopy.
Comb spacing that is given by a repetition rate for a pulsed laser is largely fixed for a given MLL by the physical dimension of the laser cavity and physical reconstruction of the system is required to change the comb spacing.
Mode-locked femtosecond lasers are vastly more expensive and less robust than the present approach.
A new measurement method which utilizes electro-optic phase modulators, arbitrary waveform generators (AWG) and frequency multipliers to generate phase components from a continuous-wave laser has been created. The multi-heterodyne technique has significant advantages in comparison to traditional frequency scanning continuous-wave methods:
The entire absorption spectra of a wide variety of species can be simultaneously recorded with no dead time due to wavelength scanning.
The comb spacing as well as the frequency component’s or teeth’s relative amplitudes are readily and precisely controlled and optimized at high speeds.
The components are fiber-coupled and therefore, can be readily ruggedized.
|Plusquellic, David F.; Long, David A.; Douglass, Kevin O.; Hodges, Joseph T.; Fleisher, Adam J.||7/20/2035|
|10,054,286||OPTICAL TRANSFORMER, PROCESS FOR MAKING AND USE OF SAME||
Resonant optomechanical scanning systems enable small actuators to generate large scan displacements at high frequencies enabling development of small, high-performance beam scanning systems. Spiral and resonance scanning systems have been developed for scanning fiber endoscope application, while mixed resonance galvanometer mirror scanning systems have been developed for microscopy and ophthalmology applications. While resonant systems are capable of high optomechanical displacement and high frequency operation, these systems have characteristic velocity variation of the projected beam across the scanned, field-of-view (FOV). Imaging modalities that require uniformity of illumination have addressed this issue by clipping the outermost portion of the scan or by over sampling a portion of a scan. These solutions are not ideal in that they decrease FOV and photon efficiency of the optical system or result in large differences in scanned solid angle per unit time. The creation and use of an optical transformer mitigate these issues and allow for linear scans across a great portion of the FOV.
It has been discovered that an optical transformer including an optomechanical member to produce a primary light (e.g., having a bounded periodic motion (BPM) or a substantially periodic motion) and a lens to transform the primary light to a secondary light produces the secondary light with a selected scan that is substantially linear from a nonlinear scan of the primary light. The secondary light cumulatively, over time, substantially fills a field of view (FOV) uniformly. Advantageously, the secondary light can be a substantially linear scan. Therefore, the optical transformer optically transforms the primary light having a nonlinear resonant scan to the secondary light having a linear scan to uniformly fill a selected FOV.
|Brown, Christopher M.; Melcher, John; Stranick, Stephan J.||11/6/2036|
|9,834,747||METHODS AND APPARATUS FOR TRANSPLANTATION OF NUCLEIC ACID MOLECULES||
This invention mitigates a problem that occurs during conventional transfer of nucleic acids into a biological cell: Nucleic acids outside cells, extracted from an organism or synthesized from oligonucleotides, are fragile and can be damaged by the shear forces that occur during fluid flow. These damages reduce the likelihood of a successful transfer. This problem is particularly acute when nucleic acids are large. For example, a large nucleic acid molecule with more than 100,000 base pairs tends to be more fragile and more susceptible to damage from shear forces, than a smaller nucleic acid.
This microfluidic device allows:
* buffers to move into and out of the chamber to make the recipient cells ready for transplantation and to trigger transplantation;
* gentle transplantation of nucleic acids into cells to occur in microfluidic chambers (e.g., by diffusion) shielded from shear forces that would damage the contents of the chamber during pipetting, or shaking;
* the chemical environment in the chamber to be controlled by fluidic methods;
* hundreds or thousands of side chambers to be arranged perpendicularly to flow channels for high throughput;
* a microscope to be used for high spatiotemporal visualization of large DNA and cells during the transfer process.
For example, for culturing cells (e.g., donor, recipient or transplanted cells), the microfluidic device delivers a steady stream of a nutrient-rich solution. Waste material produced by the cells, as well as cells that overgrow the chambers, flows away. The transplanted genetic material includes a gene for resistance to a particular antibiotic. After the cells recover from the transplantation, a solution containing the antibiotic is introduced to select for the transplanted cells and to eliminate recipient cells that did not receive the donor nucleic acids. The transplanted cells are then cultured until they overflow the chamber and enter a flow channel, from which they can be harvested as they flow out of the microfluidic device. An automated microscope with a camera is used to capture real-time visual data regarding events and objects inside the microfluidic device (such as loading of cells to chambers, lysis, transplantation, and cell culture). In addition, other sensors (e.g., embedded sensors) may be used to take real-time sensor readings of conditions (e.g., pH, temperature, pressure, or capacitance) within the microfluidic device.
|Strychalski, Elizabeth; Mershin, Andreas; Gershenfeld, Neil; Pelletier, James F.; Glass, John I.||3/21/2036|
|10,067,118||SINGLE MOLECULE FILTER AND SINGLE MOLECULE ELECTROGRAPH, AND PROCESS FOR MAKING AND USING SAME||
Nanometer-scale pores are common in biological systems and are critical for regulating biochemical processes in living systems, like the passage of ions and macromolecules through cell membranes. Biological pores can be exploited to detect small biomolecules like DNA by measuring transient changes in the pore’s ionic current. Small molecules will interrupt the flow of ions as they interact and translocate through the pore. Several manufactures are now introducing products based on this concept to sequence genes and DNA for medical applications. Reports have also shown other biomolecules like proteins may be able to be characterized using nanopores. There have been a number of attempts to fabricate nanopores using solid-state materials such as silicon nitride and two-dimensional materials such as graphene. In all cases, an electron or helium ion beam is used to ablate a hole through a membrane of the material. The diameter of the pore is generally not well controlled and the surface is amorphous because the ablation process is stochastic. Materials such as silicon nitride and graphene also tend to be electrically noisy, thereby diminishing the signal to noise ratio during the translocation measurements.
A number of problems associated with previous reports for fabricating nanopores in solid-state materials and using them for single molecule detection and characterization are remedied by this invention: 1. The invention uses a silicon dioxide tube as the pore with a well-defined inner diameter determined by controlled etching and oxidation processes. 2. Silicon dioxide is hydrophilic, and thus has superior wetting properties that are required to detect and characterize molecules in aqueous solution. 3. With previous techniques, the pore is formed through electron, gallium or helium ion ablation leaving physical damage, which could cause excessive electronic noise. In contrast, the well-controlled and precisely defined interfaces to the biomolecules made possible because of this invention could mitigate electronic noise. 4. The structure of the invention is compatible with batch fabrication processes typically used by the semiconductor industry allowing the device to be manufactured in large massive parallel arrays.
|Benjamini, Jessica; Suehle, John; Kasianowicz, John J.; Robertson, Jospeh W. F.; Balijepalli, Arvind||1/13/2037|
|10,050,608||REDUCTION OF OSCILLATOR PM NOISE FROM AM-PM NOISE CORRELATION||
The phase modulation (PM) noise reducer is a novel scheme for lowering the PM noise of an oscillator. Low PM noise, or phase instability, is among the most important metrics for oscillators used in modern civilian and military applications.
One can sense and correct an oscillator’s PM noise by measuring its PM noise in real time. However, such measurement requires a higher quality reference oscillator or a stable high-quality factor (Q) element to measure against. The PM noise reducer is new and much simpler. It requires a measurement of amplitude modulation (AM) noise only. Such a measurement is easier than a PM noise measurement, requiring only a reference voltage from, for example, a diode and a few capacitors, rather than a reference oscillator.
The PM noise reducer works by requiring a measurement of a subject oscillator’s PM noise, AM noise, and correlation between them. The AM noise of the oscillator is measured with an AM detector and a control signal of equal magnitude, same frequency response but opposite phase as the PM noise is generated. This control signal is then utilized to reduce the PM noise of the oscillator via a feed-forward error correction.
This scheme simultaneously reduces PM noise of an oscillator in steady state as well as under vibration (PM noise of an oscillator degrades under vibration). This reduction cannot be done with any existing techniques.
|Hati, Archita; Nelson, Craig; Howe, David A.||12/23/2035|
|10,082,553||MRI PHANTOM, METHOD FOR MAKING SAME AND ACQUIRING AN MRI IMAGE||
It has been discovered that a magnetic resonance imaging (MRI) phantom provides a structure having an internal volume and sample receiver for disposal of a sample in the MRI phantom and from which MRI data is acquired for determination of performance of an MRI device. Such determination can provide a comparison between the quality of operation of the MRI device over time as well as performance of the MRI device between another MRI device or comparison of MRI data to a standard image or data set, and the like. MRI data acquired using the MRI phantom can be used to validate disease mechanisms and treatments or reduce medical costs and provision of imaging service by improving image quality and reliability. Additionally, the MRI phantom can be used in multisite clinical trials for quantitative MRI or to test efficacy of novel drugs.
Beneficially, images taken on different MRI machines are comparable when using the MRI phantom because the MRI phantom can be subjected to imaging over a time interval. Further, the MRI phantom provides MRI data of diffusion, e.g., of a fluid such as water in a presence of a constant or substantially constant temperature in the MRI phantom without inclusion of a thermal effect on the fluid. A process for diffusion-weighted MRI includes using the MRI phantom to determine an apparent diffusion coefficient (ADC) in vivo for the sample disposed in the MRI phantom.
Specific design features unique to the MRI phantom device are the removable fill ports (primary and secondary) to facilitate the addition of ice water and a design constraint of no dimension larger than 194 nm to permit use in commercial MRI radiofrequency coils. Sloped structures on the main phantom shell body and the fill port undersides have been designed to easily remove air bubbles that would otherwise lead to a poor-quality magnetic resonance image. The fill ports also incorporate a handle feature to make lifting them off the main phantom shell body easy. A secondary fill port inside of the main fill port enables topping off of the phantom with water to leave no air bubbles at all, while also providing access to the center of the assembled phantom for temperature measurement by use of a long-stem thermocouple. Inset equatorial fasteners allow for a smooth outer dimension, allowing rotation. The distribution of vials within the interior of the phantom permits determination of spatial dependence of magnetic resonance parameters.
|Boss, Michael A.||2/24/2037|
|10,050,722||SIGNAL GENERATOR, PROCESS FOR MAKING AND USING SAME||
There is an increasing need to generate high spectral purity microwave signals at arbitrary, user-defined frequencies and phases to:
increase the resolution in Doppler and multi-static radar:
improve the performance of high spectral efficiency advanced communication systems;
increase the precision and accuracy in microwave spectroscopy; and
improve time and frequency metrology of microwave atomic clocks and oscillators.
The current state-of-the-art in agile electronic frequency synthesis relies on a radio or microwave frequency source (such as quartz crystal) as the basis of the synthesis chain. This limits the spectral purity and frequency stability of the resulting synthesized signal. This signal generator replaces the traditional microwave reference with an optically derived array of equally spaced radio/microwave frequencies by photodetecting a train of optical pulses. Such frequency lines have demonstrated spectral purity and stability orders of magnitude greater than traditional electronic sources, but do not exhibit the broadband frequency agility of traditional electronic synthesizers.
This invention adds frequency agility to the optically derived microwave signals while maintaining the high spectral purity and stability. This is done by using one of the frequency tones to clock a direct digital synthesizer (DDS) to generate any frequency within approximately half the clock frequency. The frequency tuning range is then extended by mixing the output of the DDS with any other of the photonically generated microwave tones. When the frequency output of the DDS covers the line spacing of the optical derived microwave tones, any frequency within the photodetection bandwidth may be generated with spectral purity orders of magnitude better than the current state of the art for electronic frequency synthesizers.
|Diddams, Scott A.; Quinlan, Franklyn; Fortier, Tara; Rolland, Antoine||9/30/2035|
|10,078,898||NONCONTACT METROLOGY PROBE, PROCESS FOR MAKING AND USING SAME||
Laser Trackers are the “bread and butter” for precision spatial metrology. They are typically used to measure the 3D or 6D features of larger objects for manufacturing, machine and robot calibration, assembly of modern machines, airplanes, vehicles, and device assembly. However, current laser tracker probes are limited by the fact that the object needs to be something solid and tangible. This new imaging probe does not rely on the object having to be tangible. It therefore fills in aspects of spatial metrology current laser tracker probes miss. Additionally, current touch probes: 1. need a tangible object; 2. must physically contact the object (accuracy relies on pressure); 3. limited to large objects (approximately 1 cm); and 4. not reliable at accurately measuring edges and corners.
The mother of laser trackers inventions - the NIST non-contact metrology probe: is a novel imaging-based laser tracker probe that: 1. combines camera inspection and laser tracker capability into one; 2. is Non-contact; 3. allows small objects <<1mm to be measured by a laser tracker with an accuracy of tens of microns (limited by laser tracker 4. allows one to track small objects <1mm with laser tracker 5. easily measures edges and corners 6. can measure objects that reflect as well as emit light 7. can measure objects that are not solid and not tangible (e.g., an image of an object, computer screen, hologram, laser beam, a liquid, etc.); 8. allows for multi-physics measurements with laser tracker; 9. in a single measurement, relates physical properties that correspond to camera information to the location measured with the laser tracker and 10. discriminates structural components in an object made of different materials based on spectral discrimination.
|Gordon, Joshua A.||8/26/2036|
|10,036,683||METHOD OF DETERMINING THE QUANTITY OF GAS IN A METAL CONTAINER BY MEASUREING THE PRESSURE AND MICROWAVE RESONANCE FREQUENCES AND ACOUSITIC RESONANCE FREQUENCIES||An acousto-microwave system to determine a mass M of gas disposed in a vessel includes: a microwave transmitter disposed on the vessel to transmit microwave radiation inside the vessel, a portion of the microwave radiation occurring at a microwave resonance of the vessel; a microwave receiver disposed on the vessel to receive microwave radiation communicated through an interior of the vessel from the microwave transmitter; an acoustic transmitter disposed on the vessel to transmit acoustic radiation inside the vessel, a portion of the acoustic radiation occurring at an acoustic resonance of the gas in the vessel; and an acoustic receiver disposed on the vessel to receive acoustic radiation communicated through the gas from the acoustic transmitter. The mass M of the gas is determined by analyzing the microwave radiation received by the microwave receiver and the acoustic radiation received by the acoustic receiver.||Moldover, Michael R.; Gillis, Keith A.; Mehl, James B.||11/28/2036|
|9,897,541||FLOW CELL FOR ATTENUATED TOTAL REFLECTION INFRARED SPECTROSCOPY BASED ON PRISM-COUPLED WAFERS||
This invention uses prisms to couple infrared radiation into a double-side polished wafer that serves as the internal reflection element (IRE) for attenuated total reflection (ATR) spectroscopy using a flow cell. ATR flow cells are used for flow chemistry, biology/biotech, electrochemistry, photochemistry, heterogeneous catalysis, surface science, environmental chemistry, research, quality control, and process monitoring. In the commercial market they are based on crystals (e.g., zinc, selenide and germanium). Unfortunately, these crystals must be removed from the flow cell, cleaned, polished and replaced in the flow cell oftentimes when new substances are introduced into the spectroscopy experiment. IREs typically cost $500 commercially and because of the high cost of IREs, the analytes and experiments are limited to those that do not damage or irreversibly alter the IRE, which must be treated as a reusable item.This new invention is an improvement over these commercial products due to its use of inexpensive disposable silicon wafers as the contact with the flowing material. Double-side polished float zone silicon and sapphire wafers cost around $20. This low price results in lower prices of each experimental run and makes many possible experiments feasible. Additionally, the wafers are semi-disposable and can be modified irreversibly, which allows greater flexibility in developing experiments and especially those that involve in-situ measurements of liquid-phase processing.
|Sperling, Brent A.||1/20/2037|
|10,067,088||DEVICE FOR RAPID DNA EXTRACTION, PURIFICATION, AND QUANTIFICATION||
The separation, purification, concentration, quantification, and extraction of charged analytes, such as biomolecules and deoxyribonucleic acid (DNA) from crude samples remains a technical and practical challenge. For example, crude samples may contain environmental contaminants, such as soil, blood, bacteria, particulate material, cell detritus, ionic species, and biomolecule inhibitors, which complicate analysis of the sample. Additionally, conventional apparatus and techniques for analyzing crude samples are labor intensive, time consuming, and require access to a laboratory, skilled technicians, and specialized equipment. Moreover, such apparatus and techniques typically deliver the purified analytes (e.g., DNA) in small fluid volumes, (about 50 μL) which limits further analysis. Further, conventional apparatus and methods for separation of charged analytes from crude samples may require pre-separation and post-separation sample preparation steps (e.g., filtration, centrifugation, and precipitation). Such further sample preparation steps may reduce the quantity of charged analytes delivered from the sample and lower the final concentration of charged analytes. The reduction of both quantity and concentration of delivered charged analytes can negatively impact the likelihood of further post-separation analyses, such as, e.g., in the case of DNA, short tandem repeat (STR) analysis for human identification. Apparatus for separating, purifying, concentrating, quantifying, and extracting charged analytes and methods are desired.
This invention is the combination of the components that allows for extraction, purification, concentration, and quantification of DNA from crude samples, all in one rapid step. The components comprising the device are: A fused silica capillary or microfluidic channel (typically ~ 8 cm long and 75 um i.d.), having two ends, a buffer end and a sample end; a run buffer reservoir connected to one end (the buffer end) of the capillary/microchannel; a fluorescence detector, interfaced with the capillary to detect fluorescent species in the capillary; a contactless conductivity detector, interfaced with the capillary to detect the conductivity at a point along the capillary; a high voltage power supply with a high voltage electrode connected to the fluid in the run buffer reservoir; a pressure controller connected to control the pressure of the head space of the run buffer reservoir; a device for measuring the current through the capillary or microchannel; a computer or other controller to record measurements of the current through the capillary, the voltage applied, the pressure, the fluorescence detector signal and the conductivity detector signal as a function of time and to control the sequence of applied voltage and pressure required to implement the extraction, purification , concentration, and quantification of DNA.The invention is superior to current practice because it uses a different mechanism (electrophoresis) to discriminate between the DNA that is desired from a sample and other molecules in a crude sample that may be polymerase chain reaction (PCR) inhibiting. It also can be used with crude samples such as soil without pre-filtering the particulates from the sample solution; this is beneficial for field-portable applications. It is also faster than current methods for DNA extraction and purification (5 minutes as compared to 20-60 minutes). Finally, it combines DNA quantification into the extraction/purification process, which reduces the time and complexity of the overall DNA analysis process.
|Ross, David J.; Strychalski, Elizabeth; Henry, Alyssa C.; Konek, Christopher T.||6/22/2035|
|9,958,317||INTEGRATING SPHERE AND FISHEYE CAMERA SYSTEM FOR GONIOMETRIC MEASUREMENT OF LIGHT SOURCES||
Integrating spheres are commonly used for measuring the total luminous/radiant flux of light sources due to their advantages in measurement speed and overall cost compared to goniophotometers. However, the integrating sphere measurements fail to reveal any information on the luminous intensity distribution of the light source, which becomes more and more important for solid-state lighting products due to a large variety of designs and applications. Furthermore, the overall measurement uncertainty of the integrating sphere method is limited by the error resulting from the sphere's spatial non-uniformity, which is often unknown and difficult to correct. Correcting this error is not possible due to the lack of information on the intensity distribution of the light sources. In some cases, the typical intensity distribution of a light source is available from the manufacturer. However, a correction is still not possible because the exact intensity distribution of the light source is unknown while they are mounted in an integrating sphere (due to unknown angular alignment relative to the sphere). In practice, the spatial non-uniformity is inevitable because of the difficulty in applying the sphere coating or in making uniform diffuse reflective material and the use of baffles inside a sphere. To minimize the measurement error from the spatial non-uniformity of a sphere, a standard light source from a national institute of metrology (NIM) that has a similar intensity distribution is typically required so that errors from the sphere's spatial non-uniformity are mostly cancelled. But the types of standard sources are very limited.
It has been discovered that a differential goniophotometer provides a fast measurement of an angular intensity distribution of a primary light source. Instead of using a conventional goniophotometer, the differential goniophotometer includes an integrating sphere or hemisphere in combination with a fisheye lens for measurement of primary light, total luminous flux, and total radiant flux. A camera is placed on the fisheye lens in which the fisheye lens has a large field of view to measure relative luminance or radiance distribution of the primary light source over an entire interior wall of the integrating sphere. Curvilinear images acquired by the fisheye lens are used to produce a luminous or radiant intensity distribution of the primary light source, based on a characterization of the integrating sphere for a point spread function and spatial non-uniformity. The absolute angular intensity distribution of the primary light source is obtained with calibration of the primary light source for total luminous flux or total radiant flux. The measured angular intensity distribution of the primary light source provides a correction of measurement error in total luminous flux, total radiant flux, and total spectral radiant flux, which can result from a spatial non-uniformity of an integrating sphere.The new sphere method can be implemented into any existing integrating system for simultaneous fast measurements of total flux and luminous/radiant intensity distributions of light sources with little increase in cost ($1K). Additionally, the luminance/radiance distributions of light sources can be measured inside an integrating sphere even with the highest coating reflectance of 98 %. Measurement of a luminance/radiance distribution inside a sphere with a lower coating reflectance such as 90 % is much easier because the difference of luminance/radiance inside the sphere is much larger. Also, a sphere with a low coating reflectance is more stable and less susceptible to the self-absorption error, but it tends to be less uniform. However, the error from the spatial non-uniformity of the sphere can be corrected using the newly developed sphere method.
|9,941,837||AN LED-BASED COMBINATORIAL FLUX ADDITION METHOD FOR PHOTOVOLTAIC SOLAR CELL NONLINEARITY MEASUREMENTS||
In the solar cell measurement field, there have been reports of two kinds of nonlinearity verification methods. One involves performing irradiance-mode spectral response measurements as a function of light bias (LB) current. The second method includes a simple flux addition method using a dual light source approach. The measurement from the first technique requires the use of complicated optics and an elaborate setup and reliance on the use of a calibrated reference photodetector whose linearity response over the low light conditions of the modulated monochromatic beam has is previously verified by another method. Additionally, this method can be time consuming especially when the light bias current needs to vary over many orders of magnitude. The second method based on comparing the ratio of added photocurrents obtained from two light sources, such as tungsten sources or two LEDs to their combined two-source output, can reveal device nonlinearity, but does not provide any insight on the actual nonlinear relationship.
This new NIST novel invention resolves these issues. It consists of two LED lamps (can be extended to sets of LED lamps of many different colors) that are remotely controlled by two LED drivers that supply certain amounts of current, first to each LED separately (singular currents), and then a combination of these unique currents to both LEDs at the same time (combination currents). A solar cell is placed in the path of the light flux generated by these LEDs. The cell can be illuminated by the LEDs in free space or through a medium such as a light pipe, ensuring maximum excitation. For each supplied current, a short circuit current signal is recorded from the solar cell. The LEDs are pulsed, for better stability, and the photogenerated current from the cell is an AC current that is first converted to voltage using a transimpedance preamplifier with a gain. This voltage is then measured by a lock-in amplifier. A lock-in amplifier only measures AC signals of a certain frequency (the pulsed frequency of the LED supplied current), therefore, the signal to noise ratio is very high. The objective is to use the measured solar cell signals and calculate the incident fluxes, taking advantage of the physical property that flux is an additive quantity. This is achieved by constructing an over determined linear system of equations, based on an Nth degree polynomial model for the relationship between signals and fluxes. These equations are solved using linear least squares fit, to solve for unknown fluxes and the degree coefficients. If the relationship between the generated signals and the incident fluxes is linear, then no higher order terms above 1 are required. However, for nonlinear devices, it may be necessary to solve for 4th or 5th degree polynomial terms. Generally, the quantity of interest is the ratio of signal to flux, r, vs. signal. If r is fixed as a function of signal, the cell is considered linear. However, there are many types of solar cell devices that show a changing r, indicative of nonlinear behavior. From a fundamental physics perspective, knowledge of this non-linear relationship can be useful in understanding or modeling charge carrier recombination phenomena or the role of defects on device performance. From a practical measurement perspective, reference solar cells or detectors that are used to measure the output of other test cells or modules are typically required to have a linear short circuit current output with irradiance over the range of interest. Since the plane of incidence irradiance level is set and monitored using linear short circuit current measurements of a reference cell, it is imperative that such devices have a linear output with irradiance, particularly over the standard reporting conditions. If the reference cell is not linear and no other substitute cells are available, then the irradiance measurements can be corrected based on knowing the mathematical relationship between the signal and the flux.
The aspects of this invention that are new are: 1. The two selected LEDs are first pulsed individually (creating singular fluxes), and then pulsed together in a combinatorial fashion, 2. The combination fluxes can be as many as desired, but more combinations provide a better fit outcome. This approach allows for the implementation of a very simple algorithm and the singular and combinatorial signals are simply recorded in a spreadsheet without the need for de-convoluting one from another, 3. The lock-in based technique provides for great signal to noise detection, 4. To take advantage of all the flux the LEDs can generate or to improve light mixing when using many LEDs, the light from both LEDs (or both LED sets) can first be coupled into a light pipe, which can then direct the mixed light to the solar cell location, 5. The data is analyzed within the framework of a polynomial-form, overdetermined linear system of equations of up to Nth degree to solve for the unscaled ratios of signal-to-flux. The goodness of the fit is determined by considering the residuals and their pattern, and 6. The unscaled ratios can be scaled based on a known flux measurement using a previously calibrated detector.
|Hamadani, Behrang; Shore, Andrew M.; Yoon, Howard W.||10/29/2036|
|9,899,197||EXTREME-UV ATOM PROBE TOMOGRAPHY INSTRUMENTATION||
NIST has created a new laser-assisted atom probe tomography (L-APT) tool. This tool uses photoionization at extreme ultra-violet (EUV) laser photon energies in the approximate range of 10 - 100 eV to promote photoionization and photo-disassociation of atomic species and molecular complexes that comprise the nano-needle-shaped specimen under examination. This new approach employs a completely different means for ionizing atomic species than what is used in conventional L-APT tools. In conventional approaches, thermal pulses imparted on the specimen tip from a pulsed visible/near-ultra-violet laser decrease the activation energy barrier for field evaporation of ions while the specimen is subjected to a strong electric field. Conventional L-APT is problematic since for a given applied field, evaporation efficiency under these conditions varies strongly depending upon the chemical composition of the specimen under examination as well as the location of an atom on the physical surface of the specimen.
The new NIST system represents a great improvement since it will employ an alternative pathway to field evaporation via direct photo-ionization of all chemical species. This feature will promote efficient single-atom photoionization across the periodic table, which will help mitigate ambiguous chemical assignments that plague current thermally-driven processes. The system also will incorporate in situ electron-beam imaging of the specimen that will provide near-real-time measurement of the specimen shape. This dimensional information will be fed immediately to reconstrnction and analysis algorithms without the need to interrupt data collection or dismount the sample. This new approach (incorporating both photoionization via an EUV laser and in situ specimen tip shape evaluation) to L-APT will offer substantially more reliable and faster analysis than what is currently possible.
|Diercks, David R.; Sanford, Norman A.; Chiaramonti Debay, Ann; Gorman, Brian P.||8/2/2036|
|9,951,271||COMBINATION LIVE AND FIXED WHOLE-CELL FLUORESCENT STAIN FOR EFFECTIVE CELL IDENTIFICATION ADN SEGMENTATION IN FLUORESCENT MICROSCOPY||
Cellular imaging technologies rely heavily on the use of fluorescence staining in a wide array of various techniques and assays. Whole-cell staining serves as a practical means of cell tracking, cell counting, and cell phenotyping for techniques such as High Content Screening (HCS) or quantitative fluorescence microscopy. Overall, whole-cell fluorescent stains typically highlight cell surface or cytoplasmic factors that are common in most cell types and provide contrast for the edge of the cell body. In many scenarios, there is a need to have a fluorescent dye that can be used to permanently label either live or fixed cells for direct comparison between the two types of samples, stain cells brightly, have low background staining, and be non-toxic. The majority of the techniques to permanently fluorescently stain cells rely on having cells fixed and permeabilized to allow the dyes access to the cytoplasmic space. While being standard practice for fluorescent microscopy, both fixation and permeabilization can affect cell shape and protein localization. Additionally, since the cells are dead, those fluorescent dyes cannot track the dynamic changes of live cells.
4,4-Difluoro-4-bora-3a,4a-diaza-s-indacene (BODIPY®, Molecular Probes/Invitrogen) dyes offer an alternative to the traditional fluorescent dyes due to their high quantum yield, small stokes shift, high photostability, and their relatively insensitivity to their environment. In additional to those properties, the BODIPY core structure is much more hydrophobic than other fluorophores, which may allow it to be cell permeable. While there are several BODIPY dyes commercially available, NIST has developed a new synthetic strategy for BODIPY-based fluorophore that is easy, inexpensive, and used routinely as a live or fixed whole-cell fluorescent stain without any additional structural modification or assay protocol modifications. This leads to more robust measurements that can transcend the physical status of the cells which are being fluorescently stained for subsequent measurements. Ultimately it can be used as a reagent in cell assay kits (i.e. cell morphology, antibody staining concentration) and sold directly as a reagent to synthesize other fluorescent compounds.
|Elliott, John T.; Arnatt, Christopher||10/14/2036|
|9,952,293||Pb(ZrxTi1-x)O3 (PZT) / COBALT-NICKEL HETEROSTRUCTURE WITH VOLTAGE-TUNEABLE PERPENDICULAR MAGNETIZATION||
NIST developed a Cobalt-Nickel multilayer with strong perpendicular magnetization that is suitable for growth on piezoelectric PZT. Strain mediated by the PZT can modulate the magnetic coercivity by over 30 %, a promising benchmark for strain- tuneable perpendicular magnetization. A strong perpendicular magnetic anisotropy field is "good" because it ensures that for technologies based on encoding digital information in the magnetic orientation, thermal energy from the environment cannot disturb the encoded data. On the other hand, this strength is also a problem, because it requires large energy to rewrite data encoded in the magnetization orientation of a particular "domain" in the (say, change a '1' to a 'O' or vice-versa).
Finding new ways to reduce the energy cost to write data on high anisotropy magnetic materials has motivated NIST to search for the best combination of ferromagnetic thin film with piezoelectric substrate. This invention uses a voltage applied through the thickness of a Pb(Zr,Ti)03 (PZT) slab to generate compressive and/or tensile strains in the two lateral directions orthogonal to the thickness. Voltage-generated strains in the PZT apply corresponding stresses to the magnetic film that has been grown directly on top of the slab. Lateral strains resulting from these stresses
Cobalt-Nickel multilayer is a new and useful improvement on previous embodied hybrids between ferromagnets and piezoelectrics and is the first time that such a multilayered film has been proposed and proven to grow on a functional piezoelectric substrate.
|Gopman, Daniel Bernard; Shull, Robert D.||12/30/2036|
|9,970,859||MODULAR APERTURE SYSTEM FOR MICROSCOPY||A detector mask transmits selectively a plurality of probe particles to a particle detector, the detector mask includes: a plate including a plate wall disposed in the plate and enclosing a transmission orifice arranged in a transmission profile to: transmit probe particles having a trajectory coincident with the transmission orifice, block probe particles having a trajectory external to the transmission orifice, and form a probe particle beam comprising the probe particles transmitted by the transmission orifice to the particle detector, wherein the transmission profile includes a sector, a semi-circle, an annular sector, or a combination including at least one of the foregoing first transmission profiles.||Holm, Jason D.; Keller, Richard; Rice, Katherine P.||1/11/2037|
|10,060,946||AFM CANTILEVER VIBRATION DETECTION WITH A TRANSMITTED ELECTRON BEAM||
This invention is a new approach for detecting oscillations of an atomic force microscopy (AFM) cantilever with a focused electron beam. The approach alleviates the inherent minimum cantilever size of several micrometers that is detectable using a conventional laser/photodiode detection system by employing a 1 nm 30 keV electron probe. This is the first demonstration of the direct detection of AFM cantilever oscillations with a stationary high energy particle beam.
An AFM cantilever and piezoelectric actuator are attached to a scanning electron microscopy (SEM) sample holder and placed in an SEM chamber between the electron source and an annular shaped electron sensitive detector. Electrical connections to the piezoelectric actuator are made through an electrical feedthrough vacuum port on the SEM chamber wall. An oscillating drive voltage is applied to the piezoelectric actuator, which oscillates the AFM cantilever and tip at the applied frequency and amplitude. A transmitted dark field SEM image of the oscillating AFM probe is acquired with the SEM. The image intensity at each point on the AFM tip is proportional to the density and thickness. The intensity increases linearly with distance from the AFM tip due to the increasing thickness of material interacting with the electron beam, which causes more electron scattering to the annular detector.
After acquiring the image, a focused stationary electron beam is positioned on the AFM tip within 100 nm of the end of the tip, and the transmitted electron detector signal is read directly with an oscilloscope. Because the AFM tip is oscillating, the amount of electron scattering is oscillatory with time due to the changing material thickness interacting with the stationary electron beam. To extract the oscillation frequency and amplitude of the AFM tip, the oscillatory electron scattering signal is captured by the transmitted electron detector and enters a lock in amplifier that multiplies the electron signal with the drive voltage signal. This technique has been used to determine resonant frequencies of AFM cantilevers up to drive frequencies of 440 kHz. The technique is limited by the stability of the AFM tip with respect to the electron beam and the bandwidth and sensitivity of the transmitted electron detector for detecting high frequency (> 1 MHz) oscillations.
|Woehl, Taylor J.; Wagner, Ryan B.; Killgore, Jason P.; Keller, Robert (Bob) R.||3/3/2037|
|9,809,452||DETERMINISTIC FORMATION OF SURFACE-DIRECTED NANOCHANNELS||
NIST presents a method for in-plane formation of nanochannels in semiconductor materials. Using this approach location, length, width, and end points of a nanochannel can be controlled. Nanochannels are formed by a metal-catalyzed surface etch reaction which is propelled by introduction of oxygen or water vapor to the heated surface of a semiconductor. During the heating cycle, metal catalyst nanoparticles such as Au and the semiconductor react forming solid or liquid alloys. The dissolved semiconductor in an Au particle reacts with the water or oxygen at the particle surface and becomes oxidized. The oxidized species depart from the Au particle surface. Iteration of dissolution of semiconductor in Au particle and its escape results in formation of surface-directed nanochannels.
|10,073,026||OPTICAL DEVICE FOR SORTING PARTICLES BY SIZE||
Particle sorting is used in a number of fields including atmospheric monitoring, workplace air quality monitoring, nano-particle manufacturing, semiconductor manufacturing, pharmaceutical manufacturing, medical research, and homeland security.
Sorting is prerequisite to measurement, analysis, and detection of particles. This invention sorts aerosol or colloidal particles by size using optical forces. It consists of a laser-pumped optical cavity that establishes a relatively large, high-intensity standing-wave optical field. Particles flowing across the optical field take different trajectories through the field based on particle size. Particles exiting the optical field are dispersed in a direction perpendicular to the direction of flow. Sorting can be performed for particles in the size range 10 nm to 10 µm.
The invention differs from the dominant technology, the diffusion mobility analyzer (DMA), in that the method of sorting is based on optical not electric forces and is more direct, i.e., requires fewer questionable assumptions. It does not require modification of the particles as does the DMA. This enables measurement of more delicate particles, such as biological particles.
Particle sorting is used in a number of fields including atmospheric monitoring, workplace air quality monitoring, nano-particle manufacturing, semiconductor manufacturing, pharmaceutical manufacturing, medical research, and homeland security. With improvement in state-of-the-art, these capabilities could find additional application in fields such as healthcare and forensics.
Sorting is prerequisite to measurement, analysis, and detection of particles.
The invention sorts aerosol or colloidal particles by size using optical forces. It consists of a laser-pumped optical cavity that establishes a relatively large, high-intensity standing-wave optical field. Particles flowing across the optical field take different trajectories through the field based on particle size. Particles exiting the optical field are dispersed in a direction perpendicular to the direction of flow. Sorting can be performed for particles in the size range 10 nm to 10 µm.
The invention differs from the dominant technology, the diffusion mobility analyzer (DMA), in that the method of sorting is based on optical not electric forces and is more direct, i.e., requires fewer questionable assumptions. It does not require modification of the particles as does the DMA. This enables measurement of more delicate particles, such as biological particles.Particle sorting is used in a number of fields including atmospheric monitoring, workplace air quality monitoring, nano-particle manufacturing, semiconductor manufacturing, pharmaceutical manufacturing, medical research, and homeland security.
|Levine, Zachary H.; Curry, John J.||6/26/2037|
|10,048,567||PROCESS AND ARTICLE FOR ELECTRONICALLY SYNTHESIZING LIGHT||
This invention is a method and apparatus for optical-to-microwave conversion and synthesis of lightwaves directly with electronics. The invention's electronic synthesizer for light creates a frequency comb in which all the modes of the comb are directly traceable to one electronic signal. It is composed of four essential pieces: an electro-optic modulation (EOM) frequency comb, novel optical-domain filtering of electronic noise, a new design for the nonlinear optics needed for spectral broadening of >1 picosecond (ps) optical pulses, and an f-2f nonlinear interferometer for carrier-phase detection. The invention works by imposing a microwave-electronic modulation onto a continuous-wave (CW) laser to create an EOM frequency comb. The electronic modulation transforms the CW laser into a train of optical pulses at the microwave rate. We then use two novel optical-domain processes that enable electronic synthesis of light, optical filtering of electronic noise and spectral broadening with >1 ps pulses to generate a coherent supercontinuum. With the supercontinuum, we use the f-2f technique for carrier-phase detection, which directly links the CW laser frequency to the microwave-electronic modulation signal.
The invention's EOM frequency comb will enable diverse applications, including electro-optical signal conversion, spectroscopic detection of molecules, coherent optical communications and optical imaging, and as a diagnostic tool for medical imaging. Our invention brings highly unique features to these applications from a widely tunable frequency comb with wide mode spacing to a coherent optical-microwave interface to robust, deterministic frequency comb generation.
|Papp, Scott; Diddams, Scott A.; Beha, Katja; Cole, Daniel||3/20/2037|
|10,067,031||OPTICAL FREQUENCY MEASUREMENT AND CONTROL USING DUAL OPTICAL-FREQUENCY COMBS||
This invention is a photonic-chip optical synthesizer, which produces a laser output in optical fiber with a user-defined optical frequency. The invention is based on microresonator optical frequency combs and other heterogeneously integrated photonic components such that revolutionary performance in terms of low power consumption, ultracompact size, and ultralow noise is possible.
The new element of this invention is the use of all photonic chip components for the creation of an optical frequency synthesizer, which enables low cost and highly scalable fabrication through semiconductor processing techniques as well as dramatic advances in size, weight, and power metrics. The invention works by leveraging two key concepts: (1) optical frequency combs can be created by purely nonlinear optical means through microresonator technology, hence the frequency comb needed for optical synthesis is dramatically smaller and simpler than in previous cases, and (2) heterogeneous photonic integration technology built on advanced semiconductor processing makes it possible to robustly connect the different pieces of an optical synthesizer in a small and highly scalable manufacturing process.
The optical frequency synthesizer invented solves the problem of generating an SI-calibrated laser source in a small, low-cost, manufacturable package. Whereas current optical synthesis technology is largely confined to the research laboratory, the technology of this invention makes it possible to create a synthesizer capable of being deployed to the field and adopted by non-specialists.
|Papp, Scott; Srinivasan, Kartik; Diddams, Scott A.; Vahala, Kerry; Bowers, John||5/8/2037|
|10,079,467||OPTOMECHANICAL LASER FOR DYNAMIC MEASUREMENTS||
A Vertical-External-Cavity-Surface-Emitting-Laser (VECSEL) comprises an external mirror that completes the lasing cavity. Changes in the separation between the light-emitting semiconductor chip and the external mirror directly modulate/tune the frequency/wavelength of the output laser light. Therefore, variations of the external cavity length can be accurately measured as frequency changes of the resulting laser.
The invention of an "Optomechanical Laser" emerges from our idea of building the chip-mirror assembly as part of a well-known mechanical structure. This mechanical oscillator converts a certain physical observable, such as acceleration or force (among others), into a length change of the external cavity. The optomechanical laser is a displacement-to-frequency transducer, which enables the measurement of a physical observable as a frequency that can be measured with exquisite accuracy.
|Pratt, Jon R.; Taylor, Jacob M.; Cervantes, Felipe G.||6/27/2037|
|10,049,710||ROTATION OF SPINS IN SPIN-ORBIT EFFECTS WITH A FERROMAGNETIC FILM FOR APPLICATIONS IN MAGNETIC APPARATUS||
Spin torque transfer random access memory (STT-RAM) is currently under development by most semiconductor manufacturers. By using the magnetization of a nanoscale patterned magnetic element to record information, STT-RAM combines multiple desirable features into a single memory technology: non-volatility, low-power, infinite write endurance, small size, scalability, and CMOS-backend fabrication capability. While standalone STT-RAM memory chips are already being shipped as a commercial product, the primary interest is driven by the need for a replacement for the conventional, large format, power hungry static RAM (SRAM) technology that is commonly employed for the cache memory on CPUs.
To write information in STT-RAM, the spin torque transfer effect is employed, whereby a large bias voltage applied to a tunnel junction with two magnetic electrodes can exert a torque on the electrode that stores the information, causing the magnetization to switch by 180 degrees. The polarity of the applied voltage determines the orientation of the magnetization in the memory electrode. Readout is accomplished via the tunneling magnetoresistance effect (TMR), whereby the effective resistance of the tunnel junction is small when the two magnetic electrodes are magnetized parallel to each other, whereas the resistance is much larger when the electrodes are magnetized antiparallel to each other.
Due to the detailed physics of the spin torque transfer process, the preferred orientation of the magnetization in the electrodes is perpendicular to the plane of the silicon wafer. This orientation significantly improves thermal stability while also reducing the voltage required to write a bit.
A significant challenge for the scaling of STT-RAM for integration into future product lines is the need to continuously reduce the inherent resistance of the magnetic tunnel junction (MTJ) as the bit area is reduced. Such a reduction is necessary because the decreased device cross-section increases the overall resistance of the memory, which diminishes the TMR signal needed to read the memory state. This requires further reductions in the tunnel junction thickness, which eventually results in significant reduction in write endurance, i.e. the number of write cycles the memory can withstand.
It has been proposed that a different physical process, the spin Hall effect (SHE), can be used to generate the torque necessary to write the STT-RAM bit, without the need to apply large bias voltages to the MTJ itself. With the SHE, current passing laterally through a nanowire consisting of heavy metals, such as Pt or Ta, generates a torque in a magnetic overlayer. The torque is oriented perpendicular to the direction of current flow, but in the plane of the semiconductor wafer. While such a torque is effective at switching in-plane orientated magnetic bits, it cannot switch the perpendicular oriented bits favored for STT-RAM applications.
Our invention overcomes this fundamental hurdle to the use of SHE for STT-RAM technology. We have found that replacement of the heavy metal nanowire with a transition-metal ferromagnetic (FM) nanowire separated from the memory element by a Cu spacer can efficiently generate a spin torque perpendicular to the semiconductor plane, thereby permitting SHE to switch perpendicular-oriented magnetic memory elements. The key physics at play in this new discovery is the large rotation of the torque via the spin-dependent reflection of spin-polarized electrons at the interface between a ferromagnet and Cu. The SHE produces a torque that is oriented transverse to the current flow direction but in the film plane. This torque is then rotated about the in-plane magnetization of the FM wire so that is it now oriented perpendicular to the film plane. The torque then enters the perpendicular memory element, causing it to switch via the spin torque transfer process. As such, this invention will greatly facilitate the use of SHE for STT RAM, and it will permit the semiconductor industry to maintain STT-RAM on the semiconductor road map for many generations to come.
|Silva, Thomas J.; SHAW, Justin; Edwards, Eric; FAN, Xin; Nembach, Hans||9/5/2037|
|10,007,885||OPTIMAL AND SECURE MEASUREMENT PROTOCOLS FOR QUANTUM SENSOR NETWORKS||
This new invention is a protocol that optimally uses quantum entanglement in a network of quantum sensors to optimally measure any desired linear combination of the fields at the sensors. This is the first protocol for using entanglement to improve measurements done by distributed quantum sensor networks. The protocol works by distributing a specific entangled state (a multi-particle GHZ state) across the network of sensors, then local pulses are used to dial the specific desired linear combination of the fields, and finally local measurements are used to read out the desired linear combination. This protocol is optimal (i.e. best possible allowed by quantum mechanics) and secure (against eavesdroppers compromising some of the sensors). This new invention is a protocol that optimally uses quantum entanglement in a network of quantum sensors to optimally measure any desired linear combination of the fields at the sensors. This is the first protocol for using entanglement to improve measurements done by distributed quantum sensor networks. The protocol works by distributing a specific entangled state (a multi-particle GHZ state) across the network of sensors, then local pulses are used to dial the specific desired linear combination of the fields, and finally local measurements are used to read out the desired linear combination. This protocol is optimal (i.e. best possible allowed by quantum mechanics) and secure (against eavesdroppers compromising some of the sensors).
|Gorshkov, Alexey V.; Foss-Feig, Michael; Eldredge, Zachary; Rolston, Steven L.||7/14/2037|